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CONTENTS
LIST OF ABBREVIATIONS ......................................................................................................... vi GLOSSARY OF TERMS............................................................................................................ viii EXECUTIVE SUMMARY............................................................................................................ xiii INTRODUCTION ........................................................................................................................... 1
Environmental Approvals ............................................................................................... 1 Proponents ..................................................................................................................... 2 Background .................................................................................................................... 2 Relevant Research......................................................................................................... 3 Outline of Water Reuse Project...................................................................................... 6 Legislative Control........................................................................................................ 10
DETAILED DESCRIPTION OF PROPOSAL.............................................................................. 13 Location ...................................................................................................................... 13 Climatic Considerations ............................................................................................... 16 Land Tenure ................................................................................................................. 16 Proposed Project Schedule.......................................................................................... 23 Proposed Location ....................................................................................................... 24 Proposed Layout .......................................................................................................... 26 Detailed Description of SAT Scheme........................................................................... 28 Detailed Description of Horticulture Scheme ............................................................... 39
JUSTIFICATION FOR THE PROPOSAL ................................................................................... 51 Need ...................................................................................................................... 51 Choice of Water Treatment Scheme............................................................................ 52 Alternative Sites ........................................................................................................... 53 Cost Benefit Analysis ................................................................................................... 54
PUBLIC CONSULTATION.......................................................................................................... 58 SOIL DISTURBANCE AND SALINITY....................................................................................... 59
Existing Environment ................................................................................................... 59 Potential Impacts.......................................................................................................... 65 Safeguards ................................................................................................................... 68 Summary of Potential Impacts and Safeguards........................................................... 73 Further Investigation and Assessment......................................................................... 77
GROUNDWATER RESOURCES................................................................................................ 78 Water Protection Zones ............................................................................................... 78 Regional Geology & Groundwater ............................................................................... 79 Local Geology and Groundwater Systems, Flow and Use .......................................... 83 Potential SAT and Horticulture Scheme Impacts......................................................... 86 Other Potential Upstream Pollution Sources ............................................................... 90
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Further Investigation and Assessment......................................................................... 91 SAT OPERATION AND MANAGEMENT................................................................................... 92
Palaeochannel Characterisation .................................................................................. 92 SAT Scheme Suitability.............................................................................................. 102 Potential SAT Impacts................................................................................................ 104 Proposed Safeguards ................................................................................................ 106 Summary of Potential Impacts and Safeguards......................................................... 114 Further Investigation and Assessment....................................................................... 119
WASTE MANAGEMENT .......................................................................................................... 120 Waste Products of SAT Scheme................................................................................ 120 Waste Products of Horticulture Scheme.................................................................... 121 Summary of Potential Impacts and Safeguards......................................................... 121 Further Investigation and Assessment....................................................................... 123
BIODIVERSITY ......................................................................................................................... 124 Existing Environment ................................................................................................. 124 Potential Impacts........................................................................................................ 128 Safeguards ................................................................................................................. 129 Summary of Potential Impacts and Management ...................................................... 131 Further Investigation and Assessment....................................................................... 137
HERITAGE / CULTURAL ISSUES ........................................................................................... 138 Existing Cultural Sites of Significance........................................................................ 138 Potential Impacts to Cultural Values .......................................................................... 138 Safeguards ................................................................................................................. 138 Summary of Potential Impacts and Management ...................................................... 139 Further Investigation and Assessment....................................................................... 140
SOCIO-ECONOMIC ENVIRONMENT ...................................................................................... 141 Existing Environment ................................................................................................. 141 Potential Impacts........................................................................................................ 141 Safeguards ................................................................................................................. 144 Summary of Potential Impacts and Management ...................................................... 148 Further Investigation and Assessment....................................................................... 155
ENVIRONMENTAL MANAGEMENT PLAN ............................................................................. 156 Environmental Commitment....................................................................................... 156 Environmental Management of Construction Activities ............................................. 157 Environmental Management of Operational Activities ............................................... 157 Measures for Ensuring Safeguards are Effectively Applied....................................... 157 Periodic Review.......................................................................................................... 158
FURTHER READING................................................................................................................ 159
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TABLES Table 1: Components of the Proposal and Responsibility. ..........................................................2 Table 2: Recent Background Research Reports..........................................................................3 Table 3: Previous Background Research Reports .......................................................................4 Table 4: Land Use Zones in the Region of the Proposed SAT and Horticulture Schemes........18 Table 5: Project Stages and Indicative Timetable ......................................................................23 Table 6: AZRI Soil Aquifer Treatment Scheme Design Parameters ..........................................33 Table 7: Median Concentrations of Determinants in Recycled Water Exiting the Alice Springs
Waste Stabilisation Ponds 2003-2004. ........................................................................36 Table 8: Summary of Water Quality Guidelines for Water Reuse..............................................42 Table 9: Classes of Reuse Water...............................................................................................43 Table 10: Summary of Acceptable Use for Different Classes of Recycled Water Quality. ........44 Table 11: Expected Pathogen Reduction...................................................................................45 Table 12: Seasonal Horticulture Activity and Equipment Usage................................................48 Table 13: Comparison of Possible Water Reuse Sites. .............................................................53 Table 14: Comparison of Costs and Benefits.............................................................................55 Table 15: Land Capability Characteristics..................................................................................59 Table 16: Characteristics of Remnant Flood Deposit Flats ........................................................61 Table 17: Characteristics of Broad Alluvial Flats........................................................................61 Table 18: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for
Soils and Salinity. .........................................................................................................74 Table 19: Summary of Site Characteristics for SAT Schemes.................................................103 Table 20: Groundwater Monitoring during Commissioning ......................................................107 Table 21: Groundwater Monitoring during SAT and Horticulture Operation ............................108 Table 22: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Soil
Aquifer Treatment. .....................................................................................................115 Table 23: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for
Wastes. ......................................................................................................................122 Table 24: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for
Biodiversity. ................................................................................................................132 Table 25: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for
Heritage and Cultural Aspects. ..................................................................................140 Table 26: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for
Socio-Economic Environment. ...................................................................................149
FIGURES Figure 1: Schematic Depiction of Soil Aquifer Treatment ............................................................7 Figure 2: Location of Project Area. .............................................................................................14 Figure 3: Topography and Drainage of the AZRI Site. ...............................................................15 Figure 4: Mean Monthly Rainfall, Evaporation and Waste Stabilisation Pond Overflows in Alice
Springs.......................................................................................................................16 Figure 5: Land Use Zones of the AZRI Site and Surrounding Areas. ........................................19 Figure 6: Location of Culturally Significant Aeolian Dune Features and Trees in the AZRI Sheep
Paddock.....................................................................................................................21 Figure 7: Location of Significant Trees in Proposed Horticulture Site........................................22 Figure 8: Overview of the Project Area ......................................................................................24 Figure 9: Existing Layout of AZRI...............................................................................................25 Figure 10: Conceptual Design of SAT Scheme..........................................................................27 Figure 11: Land Units of the Project Area ..................................................................................60 Figure 12: Salinity and Sodicity of Soils .....................................................................................66 Figure 13: Water Protection Zones of Alice Springs ..................................................................79 Figure 14: Underlying Geology in Northern Territory. ................................................................80 Figure 15: Broad Scale Geology of the Alice Springs Area. ......................................................81 Figure 16: Geological Cross-section from Alice Springs to Orange Creek Station....................82 Figure 17: Geology of Alice Springs. ..........................................................................................85 Figure 18: Geological Cross-section from Mt Blatherskite to the Alice Springs Airport. ............86
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Figure 19: Changes in Groundwater Height and Rainfall 1957 to 2003.....................................87 Figure 20: Conceptual Model of Recharge Sources, Recharge Rates, Flow Paths and Chemical
Processes Occurring at AZRI. ...................................................................................89 Figure 21: Groundwater Contours and Palaeochannel within AZRI Site ...................................92 Figure 22: Geological Cross-section through Palaeochannel. ...................................................93 Figure 23: Groundwater Mounding Height Contours of Steady State Infiltration at Rate of 3
m/day (600 ML/yr)......................................................................................................98 Figure 24: Groundwater Contours of Steady State Infiltration at Rate of 0.3 m/day (600 ML/yr).
...................................................................................................................................99 Figure 25: Particle Tracking Results for Calculated Layer 2 from Steady State Infiltration
Response to 640 ML/yr into ‘Kidney’ Shaped SAT Basin Design. ..........................100 Figure 26: Infiltration through Rectangular Basins at 600 ML/yr and Combined Extraction from
Four Bores Along Palaeochannel............................................................................101 Figure 27: Location of Existing Bores on AZRI. .......................................................................109 Figure 28: Land Liable to Flooding. ..........................................................................................114
PLATES Plate 1: Example of Excavation Undertaken in Costean Programme........................................64 Plate 2: Example of Dissipater at Recycled Water Inlet and Empty SAT Basins.......................71 Plate 3: SAT Basins During Filling..............................................................................................72 Plate 4: Example of a SAT Basin with Raised Perimeter Walls. ................................................72 Plate 5: Example of Recycled Water Flow Monitoring and Delivery Equipment......................110
APPENDICES Appendix 1: PER Guidelines Appendix 2: Summary of Existing Water Reuse Schemes Appendix 3: Summary of Community Consultation Appendix 4: AS: 4360 (1999) Risk Management Appendix 5: Summary of Alice Springs Geology and Groundwater Resources Appendix 6: NT Fauna and Flora Database Records Appendix 7: Construction Environmental Management Plan Soil Aquifer Treatment Scheme Appendix 8: Construction Environmental Management Plan Horticulture Scheme Appendix 9: Operation Environmental Management Plan Soil Aquifer Treatment Scheme Appendix 10: Operation Environmental Management Plan Horticulture Scheme
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LIST OF ABBREVIATIONS AAPA Aboriginal Areas Protection Authority AHD Above Height Datum Al Aluminium ANZECC Australia and New Zealand Environment and Conservation Council As Arsenic ASLUSP Alice Springs Land Use Structure Plan 1999 ASTP Alice Springs Town Plan 1992 AZRI Arid Zone Research Institute B Boron BOD Biological Oxygen Demand Ca Calcium Cd Cadmium CEC Cation Exchange Capacity CEMP Construction Environmental Management Plan Cl Chlorine CLW CSIRO Land and Water COD Chemical Oxygen Demand Cr Chromium CSIRO Commonwealth Scientific and Industrial Research Organisation Cu Copper DAF Dissolved Air Flotation DBIRD Department of Business, Industry and Resource Development DCA Development Consent Authority DHCS Department of Health and Community Services DIPE Department of Infrastructure, Planning and Environment DOC Dissolved Organic Carbon EDC Endocrine disrupting chemicals EMP Environmental Management Plan EIS Environmental Impact Statement EPBC Act Environment Protection and Biodiversity Conservation Act ESD Ecologically Sustainable Development ESP Exchangeable Sodium Percentage HCO3 Carbonate K Potassium L Litre MBAS Methylene Blue Active Substances mg milligram ML Mega Litre (1,000,000 litres) MPN/100 mL Most Probable Number (of faecal coliforms) per 100 millilitres
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Na Sodium NOI Notice of Intent NOx Nitrates and Nitrites OEH Office of Environment and Heritage OEMP Operation Environmental Management Plan ORP Oxidation Reduction Potential PER Public Environment Report PCR Polymerase Chain Reaction used to identify and quantify microbial material or
its derivatives, especially when present in very small amounts SAT Soil Aquifer Treatment SO4 Sulfate TDS Total Dissolved Salts THMFP Trihalomethane Formation Potential TKN Total Kjieldahl Nitrogen TOC Total Organic Carbon Total N Total Nitrogen TSS Total Soluble Salts WTP Alice Springs Wastewater Treatment Plant WSP Alice Springs Waste Stabilisation Ponds Zn Zinc
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GLOSSARY OF TERMS Agrochemicals A term used to describe the full range of chemical products used in modern
horticulture and agriculture practice and regulated through various agencies of the government, principally the Australian Pesticides and Veterinary Medicines Authority (APVMA). It includes herbicides, insecticides, fungicides, plant growth regulators, dormancy breaking chemicals, crop oils, wetting agents, fumigants and similar products.
Algae A diverse group of aquatic plants containing chlorophyll and other photosynthetic pigments. Many are microscopic (often being single cells) but some can be large, including the large seaweeds. They grow as single cells or aggregations of cells (colonies).
Aquifer (Unconfined and Confined)
A rock or sediment with sufficient porosity and permeability to allow storage and flow of groundwater. In an unsaturated aquifer the upper section of the aquifer is not filled with water (i.e. the aquifer can store more water). A saturated aquifer has no empty space remaining. An unconfined aquifer has no confining layers between the zone of saturation and the ground surface. A semi-confined/confined aquifer is generally saturated and partially or totally overlain by a confining layer that partially or totally inhibits recharge or discharge.
Artesian aquifer A confined aquifer in which the hydraulic pressure will cause water to rise in a bore above the upper confining layer of the aquifer. If the pressure is sufficient to cause the bore to flow at the surface, it is called a flowing artesian aquifer.
Beneficial Use The potential uses for a groundwater resource based upon water quality (i.e. drinking water, horticultural irrigation, parkland irrigation)
Biochemical or Biological Oxygen Demand (BOD)
A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater the degree of pollution.
Bore (well) Any artificial opening or altered natural opening, however made, by which groundwater is sought or through which groundwater flows under natural pressure, or is artificially withdrawn or injected.
Botrytis A fungus causing blight in grapes e.g. Bunch Rot or Grey Mould. Buffer An area of land used or designed to isolate one area of land from another so
that adverse effects arising from one area do not affect the other. Native vegetation buffers can be used, for example, to protect drainage lines, watercourses or sensitive vegetation communities and to improve public amenity.
Cation Exchange Capacity
This is the measure of the capacity of a soil to hold the major cations: calcium, magnesium, sodium and potassium (but also including hydrogen, aluminium and manganese in acid soils). It is a measure of the potential nutrient reserve in the soil and is therefore an indicator of inherent soil fertility. An imbalance in the ratio of cations can result in soil structural problems. High levels of individual cations (e.g. sodium aluminium and manganese) can also be toxic to plants.
Clearing The removal of vegetation by mechanical or chemical means, but not including removal of vegetation by grazing animals.
Coliform - Faecal Coliform
Microorganisms found in the intestinal tract of humans and animals. Their presence in water indicates faecal pollution and potentially dangerous bacterial contamination by disease-causing microorganisms.
Confined aquifer
A permeable geological formation or group of formations, saturated with water and lying between upper and lower confining layers of low permeability.
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Dissolved Air Flotation
A process for treating effluent, in which particulate matter (solids such as algae) is removed from the wastewater through movement of particles attached to small bubbles of air. The bubbles and particles float to the surface where they can be physically removed.
Dispersion A process resulting from soil aggregate break down in water, leaving clay particles forming a cloud around the aggregate. These soils generally have a high exchangeable sodium percentage. Dispersion is an indicator of sodic soils. It occurs when excessive sodium attached to clays forces the clay particles apart in water, resulting in a cloud of clay forming around the aggregate. The fine clay particles that have dispersed, act to clog up the small pores in the soil, degrading soil structure and restricting root growth and water movement. Dispersive soils usually have a high Exchangeable Sodium Percentage (ESP). The effect of ESP on soil behaviour such as dispersion is also influenced by other soil properties such as organic matter content, clay mineralogy, cation composition, sesquioxide content and particularly electrolyte concentration of the soil and of any applied irrigation water. Use of the ESP value needs to be understood in relation to the wider properties of the soil.
Drainage line A channel down which surface water naturally concentrates and flows. Drainage lines may become temporarily inundated as storm water flows across a catchment to more significant waterways or water bodies. The period of inundation is usually no more than 24 hours, however, water may be held for extended periods over the wet season. Unlike watercourses,drainage lines often do not form well defined channels.
Drawdown The difference, measured vertically, between the static water level in the bore and the water level during pumping.
Drinkable Water Water that is sufficiently free from biological, chemical, physical, or radiological impurities so that users will not be exposed to disease or harmful physiological effects.
Effluent In the context of this PER, effluent refers to untreated sewage entering the Alice Springs Wastewater Treatment Plant. It should be noted that some references cited in the PER use the term effluent in document titles to mean wastewater.
Erosion and Sediment Control Measures
Activities based on structural works, vegetation management, tillage operations and/or other management options designed primarily to achieve control of soil erosion and sedimentation.
Exchangeable Sodium Percentage
This is calculated as the proportion of the cation exchange capacity occupied by the sodium ions and is expressed as a percentage. In soil, after measuring Cation Exchange Capacity (CEC) of the soil, the proportion of exchangeable sodium relative to the summation of exchangeable cations is calculated to provide the exchangeable sodium percentage (ESP) for the soil. This simple calculation (units of %) is used to indicate the likely effects that a soil may have with respect to structural stability, because sodium ions favour dispersion and calcium and magnesium ions favour flocculation (opposite to dispersion). Sodic soils are categorised as soils with an ESP of 6 to 14%, and strongly sodic soils have an ESP of greater than 15 %. This measure is favoured by many users in preference to the SAR to discuss soil sodicity, although greater laboratory analytical work is required. The SAR is more tightly defined and used only in relation to a liquid, but may be used for a soil solution.
Extracted Water Water extracted from groundwater aquifers after SAT and storage in aquifers.
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Fertigation The application of a commercial fertilizer, soil amendment or recycled water from wastewater treatment facilities with irrigation water.
Groundwater Water that occurs beneath the land surface in the zone(s) of saturation. Groundwater resources are found within, and are typically controlled by, geological sequences underlying the Earth’s surface. Termed aquifers, where geological conditions allow sufficient storage and/or movement of water below the ground, groundwater can be present at depths and thicknesses ranging from less than a metre to many kilometres.
Gypsum This is the common mineral product calcium sulfate, prepared as a fine powder or micronised, which can be used as an ameliorant for dispersive soils. Gypsum initially provides an electrolyte effect to the soil, increasing its salt concentration. This prevents clay particles from swelling and therefore reduces dispersion. A longer term effect of gypsum is to replace exchangeable sodium attached to clay particles with exchangeable calcium which makes the soil less sodic and reduces dispersion.
Habitat The natural environment in which plants or animals exist. Impermeable A material that limits the passage of water. Infiltration The downward movement of water of surface origin into the soil or rock
formations. Land Capability The ability of land to accept a type and intensity of use permanently, or for
specified periods under specified management, without permanent damage. Land Unit An area of relatively uniform landform, soils and vegetation types. Palaeochannel An ancient river channel infilled with sediments. Perched Groundwater
Groundwater held above the regional or main water table by a less permeable underlying earth or rock material.
Permeability Measure of the ability of a rock or sediment to allow water flow below the ground
Polymerase Chain Reaction
Laboratory process used to identify and quantify microbial material or its derivatives, especially when present in very small amounts
Porosity (Primary and Secondary)
The ratio of the volume of void spaces in a rock or sediment that can be filled with air or water to the total volume of the rock or sediment. Primary Porosity represents the collective volume of original pore space when a rock or sediment was formed. Secondary Porosity results from subsequent fracturing or weathering of a rock or sediment (i.e. solution cavities in limestone).
Potentiometric Surface
The level to which water will rise in cased bores.
Recharge The process by which water is added to a zone of saturation, usually by downward infiltration from the surface.
Reclaimed Water or Recycled Water
Treated wastewater from a sewage treatment system that, as a result of treatment, is suitable for a direct beneficial purpose or a controlled use that could not otherwise occur. In the context of this PER the terms recycled and reclaimed are interchangeable and refers to water exiting the DAF treatment plant.
Registered Bore An inventoried bore that has been assigned an identification number by state agencies and whose records are available.
Runoff That portion of rainfall not immediately absorbed into, or detained upon the soil, and which thus becomes surface flow. Runoff is the major agent of water erosion. The amount of runoff depends on rainfall intensity and duration, slope, surface roughness, vegetation cover, and surface soil conditions including moisture content.
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Saturated Zone The sub-surface zone in which all openings are full of water. Screened Interval
A depth interval in a cased bore that is slotted or perforated and serves as the intake portion for water from the aquifer.
Sewage Means water-carried human wastes, including kitchen, bath, and laundry waste from residences, buildings, industrial and commercial establishments, or other places, together with such groundwater infiltration, surface waters, or industrial wastewater as may be present.
Sewage Treatment System
Any facility or equipment used to alter the quality of sewage by physical, chemical or biological means or a combination thereof, such that the wastewater is unlikely to cause degradation in water quality or other environmental conditions.
Significant Adverse Impact
Any impact resulting in degradation of an important resource, that is unacceptable because it cannot be mitigated or because of unacceptable conflicts in management of use of the impacted resource.
Sodicity This is a measure of exchangeable sodium in relation to other exchangeable cations. It is expressed as the Exchangeable Sodium Percentage. A sodic soil contains sufficient exchangeable sodium to interfere with the growth of plants, including crops. A soil with an ESP greater than 6 is generally regarded as being a sodic soil in Australia. ESP levels are further classified in the Australian Soil Classification scheme.
Sodium Absorption Ratio
This is a measure of the amount of sodium present in a solution relative to the amounts of calcium and magnesium. It is expressed as a percentage and usually measured in a liquid, or a soil solution. It is the best measure of the potential impact that irrigation water will have on soil structure and should be assessed considering interactions with water salinity. The value may also be determined for the soil solution, by extracting the soil solution from the soil.
Soil The layer of material at the land surface that supports plant growth. Soil Erosion The detachment and transportation of soil and its deposition at another site
by wind, water or gravitational effects. Accelerated soil erosion occurs primarily as a result of the influence of human activities.
Soil Salinity Soil salinity is a characteristic of soils relating to their content of water-soluble salts. Typically inorganic salts are crystalline ionic products that dissociate in water to form positively charged cations (Ca2+, Mg2+, Na+, K+,Al3+, Cu2+, Zn2+,Fe2+) and negatively charged anions (Cl-, NO3-, PO4
3-, SO42-,
CO32-, HCO3-).
Soluble salts dissociate in water to release cations and anions that can conduct an electric current. Thus, the simple measurement of how much current an aqueous solution will carry can be related directly to the amount (concentration) of salt present. Electrical conductivity is measured using a conductivity meter and electrical conductivity (EC) is reported in the international units of measure as deciSiemens per metre (equivalent to milliSiemens per centimetre).
Specific Yield The ratio of the volume of water that will drain under the influence of gravity to the volume of saturated rock or sediment.
Stakeholder Person and/or governmental entity who could or will be affected by activities. Standing Water Level (water table)
The stabilised level or elevation of the water surface in a bore that is not being pumped.
Threatened Species
A species or community that is vulnerable, endangered or presumed extinct.
Total Soluble Salts
This is a measure of the soluble salts in the soil (mainly sodium chloride, sulfate and carbonate). It is a calculated value derived using the Electrical C d tivity reading where, Total Soluble Salts % = Electrical Conductivity
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Conductivity reading where, Total Soluble Salts % = Electrical Conductivity (dS/m) x 0.33. TSS needs to be considered relative to profile water movement.
Unconfined Aquifer
An aquifer in which the water table is the upper boundary. There is no confining layer between the aquifer and the surface and the pressure at the water table is atmospheric. Water level in an unconfined aquifer may move up and down in response to local recharge or discharge.
Unconsolidated Formation
Means naturally occurring, loosely cemented, or poorly indurated materials including clay, sand, silt, and gravel.
Unsaturated Zone
The sub-surface zone, usually starting at the land surface that contains both water and air.
Vadose The layer of soil that is intermittently wet as water moves from the surface soils to groundwater aquifers.
Vulnerable Species
Species believed likely to move into the ‘endangered’ category in the near future if the causal factors continue operating.
Wastewater Sewage water, or other liquid, raw or partly treated flowing into a reservoir, basin, or treatment plant. It should be noted that some references cited in the PER use the term wastewater in document titles to mean recycled water.
Water Table The upper surface of an unconfined water body, the surface of which is at atmospheric pressure and fluctuates seasonally. The levels at which water stands in bores that penetrate the water body define the water table.
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EXECUTIVE SUMMARY The Alice Springs Water Reuse Scheme is a joint initiative of the Power and Water Corporation and the Department of Business, Industry and Resource Development (DBIRD). The proponents submitted a Notice of Intent (NOI) to the Office of Environment and Heritage (OEH) within the Department of Infrastructure Planning and Environment (DIPE) for determination of the level of environmental assessment required for the project. The outcome of that determination was that a PER was required for formal assessment. The Alice Springs Water Reuse Scheme aims to develop a water recycling scheme for the township of Alice Springs by making productive use of up to 1,800 ML (megalitres) of wastewater per year. Initially for this project, it is proposed to divert, store, extract and utilise 600 ML/yr, with a capacity to extend this to 1,200 ML/yr, should the initial monitoring demonstrate the scheme is working successfully. Community consultations undertaken as part of the Alice Springs Urban Water Management Strategy in 2000, identified the expectation that recycled water from the Alice Springs Waste Stabilisation Ponds (WSP) be put to highest value use possible, and not discharged to Ilparpa Swamp or lost through evaporation. The NT Controller of Water Resources has advised that, as of December 2005, Power and Water is to cease all dry weather discharges to Ilparpa Swamp. Power and Water has proposed to achieve this objective, as well as objectives relating to water conservation, through the development of a recycled water storage and reuse system at the Arid Zone Research Institute (AZRI), which is operated by DBIRD. It is proposed that private horticultural developments will occur on-site at AZRI for a range of crops that will utilise the reuse water. The proposal covered under the scope of this PER is for:
• Infiltration of recycled water through the ground to an underlying aquifer;
• Storage of this recycled water in the aquifer;
• Later extraction of the recycled water; and
• Reuse of extracted recycled water for horticultural irrigation.
The recycled water from the WSP will be tertiary treated using a Dissolved Air Flotation (DAF) system, or equivalent, to significantly reduce suspended solids (largely in the form of algae) and a disinfection process (chlorination) to significantly reduce the potential pathogen concentration. The proposed SAT and horticultural schemes are to be located at AZRI, 10 km south of Alice Springs in a region referred to historically as the Outer Farm Basin. The property is bounded to the north by the Todd River, to the south by Colonel Rose Drive, the Stuart Highway to the west and rural residential blocks to the east. Recycled water, delivered by the existing Recycled Water Transfer Pipeline, will infiltrate via shallow basins, known as infiltration basins. The influent recycled water will be intermittently ponded in the infiltration basins, with wetting and drying cycles of days to several weeks duration depending on site characteristics. As the infiltrate moves to the watertable below the basins, the soil acts as a natural treatment process to reduce the physical, chemical and microbial constituents of the infiltrating water. Treatment also occurs while the water moves through the aquifer in the saturated zone. Treatment occurs through filtration, adsorption onto soil of inorganic and organic substances and removal through in-situ reactions or degradation by in-situ microorganisms. Cyclic wetting and drying produces recurring aerobic (with oxygen) and anaerobic (without oxygen) conditions immediately below infiltration basins and uses the soil as a natural filter
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to reduce concentrations of contaminants in infiltrating water through physical, chemical and microbial processes. Water storage, or ‘banking’, involves depositing water in the ground via some form of artificial recharge, such as through infiltration. The water is stored in the aquifer system and can then be recovered as needed by pumping from groundwater extraction bores. Use of groundwater for a wide range of water banking purposes is common throughout Australia and internationally. It is envisaged that the initial reuse of the recycled waters will be for horticultural enterprises located within the AZRI site. However, use of the recycled water is also proposed for Blatherskite Park and other potential users along the pipeline route. This will have the benefit of improving the quality of water being supplied to Blatherskite Park under existing arrangements and there will also be the benefit of a reduced usage of the Roe Creek Borefield water, should other users substitute use of drinking water for recycled water. There are five main instruments to manage potential environmental impacts associated with this scheme, including: 1. EMPs for the operation and
construction of the SAT and horticultural schemes;
2. Application of the Water Act 1992 and the Public Health Act 1997 to control recycled water recharge and subsequent recovery;
3. Land Tenure Agreements to determine appropriate uses and associated leasing terms for access to land at AZRI;
4. Sale of Recycled Water Agreements detailing access requirements, costs, volumes; and
5. Conditions of use for the recycled water.
A range of detailed site investigations, as well as study tours of similar sites
elsewhere in Australian and overseas, have been used to determine the feasibility of the proposal at the AZRI site. The investigations include: • Geochemical and hydrogeological
investigations at the AZRI site; • Field trials of water infiltration rates; • Laboratory studies of soil clogging; • Modelling of groundwater movement,
based on field investigations into site hydrology and groundwater flow; and
• Field surveys of culturally significant sites and objects.
Other studies undertaken for other purposes have also been referred to, including: • Flora and fauna surveys in the
surrounding areas; • Groundwater investigations for the
Alice Springs area; • Water quality investigations for the
Alice Springs area; and • Irrigation practices in the Alice Springs
area and the implications of these on soil quality.
During assessment of these studies and consultation with community members, a number of potential impacts have been identified for the proposed SAT and horticultural schemes. These potentially include: • Impacts on groundwater quality and
height; • Impacts on soil chemistry, particularly
salinity and sodicity, and stability; • Impacts on vegetation, fauna and
habitats; • Impacts on neighbouring residents,
particularly in relation to rural amenity; • Impacts on culturally significant places
and objects; • Impacts on human health in relation to
reuse of recycled water; • Impacts on the regional economy, as a
result of generation of a new industry
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area for the region and resultant increase in employment opportunities; and
• Impacts on Ilparpa Swamp through cessation of dry weather overflows.
The latter two potential impacts are seen as beneficial to the Alice Springs community and do not require mitigation measures. The remainder were assessed in terms of environmental risk and safeguards to minimise or mitigate the impacts were developed accordingly. In addition, Construction and Operation Environmental Management Plans have been prepared for each of the SAT and horticultural schemes for use by the proponents and their contractors. The environmental management approach incorporates: • The principals of Ecologically
Sustainable Development; • Monitoring programmes to ensure the
effectiveness of the proposed safeguards; and
• Contingencies for use in the event that monitoring reveals that the safeguards are ineffective.
Broadly speaking, the proposed management strategies include measures for: • Reducing soil impacts, including
erosion control, irrigation techniques, soil chemistry management;
• Ensuring groundwater quality is not impacted, including monitoring of the quality of recycled water entering the
infiltration basins and monitoring of the movement of the infiltrated water in the soil;
• Minimising impacts on groundwater height, including SAT basin design and control of recycled water delivery rates to basins;
• Minimising impacts on vegetation, habitat and fauna, including retention of environmentally significant trees and habitat areas, targeted surveys for conservation significant fauna and flora species prior to clearing and enhancement of remaining vegetated areas;
• Minimising the impact on neighbouring properties through use of vegetated buffers, providing separation between access roads to the site and residents, controls on operations and inclusion of feedback mechanisms;
• Protection of culturally significant places and objects through continued consultation with the Aboriginal Areas Protection Authority and custodians of the land, prior to any on-ground disturbance; and
• Mitigating against impacts on human health by providing tertiary treatment prior to entry into the groundwater, natural treatment of recycled water during infiltration through the soil and storage in the aquifer, monitoring of the quality of recycled water used for irrigation, controlling irrigation techniques and best practice use of chemicals during horticultural operations.
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INTRODUCTION Environmental Approvals The Northern Territory Environmental Assessment Act 1982 and Environmental Assessment Administrative Procedures 1984 (referred to as the Environmental Assessment Act and Administrative Procedures) provide for the assessment of activities which could significantly affect the environment, to determine the acceptability of a proposal and to ensure that unnecessary and unacceptable harm to the environment can be avoided. The level of assessment varies depending on the sensitivity of the local environment, the scale of the proposal and its potential impact on the environment. Where it is considered that the proposed activity does not have significant or large-scale impacts, the level of assessment is generally at the Public Environmental Report (PER) level, whereas a detailed Environmental Impact Statement (EIS) and Supplement would be sought for those proposals where the environmental impact is likely to be of major significance. A Notice of Intent (NOI) was prepared by the Power and Water Corporation (PWC) in April 2004 and submitted to the Office of Environment and Heritage (OEH) within the Department of Infrastructure Planning and Environment (DIPE) for determination of the level of environmental assessment required. The outcome of that determination was that a PER was required for formal assessment of the project. A copy of the guidelines for preparation of this PER are provided in Appendix 1. The purpose of the PER is to provide information on the project so that the public may understand the need for, and details of the proposal, any alternatives to the project, impacts that may arise from the project and measures that will be taken to minimise or avoid adverse impacts. The present PER is to provide concise and comprehensive information regarding the design, construction and operation of the proposed Alice Springs Urban Water Reuse Strategy.
It should contain sufficient information to enable understanding and assessment of the scope and environmental implications of the proposal and should clearly identify the main environmental impacts associated with the development and should contain management strategies to minimise these impacts. The PER is required to be placed on public display and public and government agency comment is sought over a period of up to 28 days. Based on information contained in the PER and comments obtained, OEH prepares an assessment report for the Minister for Environment and Heritage for consideration. The Minister then decides what conditions, if any, should be applied to the project for the protection of the environment. The PER Guidelines also refer to the need for environmental management plans (EMPs) to cover construction and operation of the proposed activities. The principal objective of the EMPs is to provide management strategies that will avoid, ameliorate or mitigate potential adverse impacts associated with the proposed construction and operation activities. These are to include clear instructions for management, monitoring and performance evaluation and are to be guided by relevant legislation and other codes of practice. In addition to the assessment of the PER by OEH, certain aspects of the proposed activities are also subject to assessment by the Controller of Water Resources (within DIPE), who can apply restrictions and conditions on the recharge of recycled water into the ground and extraction of water for horticulture.
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Proponents The Alice Springs Water Reuse Scheme is a joint initiative of Power and Water and the Department of Business, Industry and Resource Development (DBIRD). Research and technical support has been provided by the Water Resources Branch of DIPE and CSIRO Land and Water (CLW).
Background The Alice Springs Water Reuse Scheme aims to develop a water recycling scheme for the township of Alice Springs by making productive use of 1,200 to 1,800 ML (megalitres) of wastewater per year. Initially, it is proposed to divert, store, extract and utilise 600 ML/yr, with a capacity to extend this to 1,200 ML/yr, should the initial monitoring demonstrate the scheme is working successfully. The Alice Springs Waste Stabilisation Ponds (WSP) presently discharge excess recycled water to the nearby Ilparpa Swamp. The nutrient rich water contributes to the growth of non-native grasses and reeds in the swamp, and provides a habitat for mosquito breeding. As advised by the Department of Health and Community Services (DHCS), mosquitoes are potential vectors for Murray Valley Encephalitis and Ross River Virus in the region.
Community consultations undertaken as part of the Alice Springs Urban Water Management Strategy in 2000 identified the expectation that recycled water from the WSP be put to highest value use possible, and not discharged to the swamp or lost through evaporation. In consultation with the community, the Conservation and Natural Systems section of DIPE went on to determine beneficial uses for Ilparpa Swamp under the Water Act, and has advised that future discharges from the WSP to the swamp be eliminated under the terms of the applicable Waste Discharge Licence. As of December 2005, Power and Water is to cease all dry weather discharges to Ilparpa Swamp. Power and Water has proposed to achieve the objective of ceasing dry weather discharge to Ilparpa Swamp through the development of a recycled water storage and reuse system at the Arid Zone Research Institute (AZRI), which is operated by DBIRD. It is proposed that private horticultural developments will occur on-site at AZRI for a range of crops that will utilise the reuse water. Table 1 indicates the major components of the proposed Alice Springs Water Reuse Scheme and the role of each proponent.
Table 1: Components of the Proposal and Responsibility. Component Responsibility Treatment – Additional treatment of recycled water from the existing waste stabilisation ponds to produce a higher quality of recycled water
Power and Water
Recharge – Transporting recycled water to potential users, for either direct open space irrigation or for recharging groundwater via Soil Aquifer Treatment (SAT)
Power and Water
Water Banking - Utilising underground storage of recycled water by using suitable geological formations
Power and Water
Water Extraction – Removal of stored recycled water through groundwater bores and pumping systems
DBIRD*
Reuse – Use of ‘banked’ water for irrigation or other high value use DBIRD** Final responsibility will be addressed under contractual arrangements with the private horticulturalist.
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Relevant Research A summary of the specific research undertaken in relation to the proposed project is provided in Table 2. The
outcomes of these studies have been incorporated into this PER.
Table 2: Recent Background Research Reports Report Purpose Knapton, A. 2004a. Alice Springs Water Reuse Scheme Soil Aquifer Treatment Project, Volume 1 - Site Characterisation.Draft, Water Resources Branch, Division of Natural Resources, DIPE, Alice Springs.
To document the results of a desktop study completed to determine the likelihood of suitable site characteristics regarding the feasibility of implementing SAT at AZRI.
Knapton A and Lennartz R. 2004. Alice Springs Water Reuse Scheme Soil Aquifer Treatment Project Volume 2 - AZRI Site Investigations. Draft, Water Resources Branch, Division of Natural Resources, DIPE, Alice Springs.
To document the site investigations completed to determine the key site characteristics regarding the feasibility of implementing SAT at AZRI.
Knapton A, Pavelic P, Dillon P and Low B. 2004a. Field Infiltration Tests with Potable Water to Predict Hydraulic Behaviour of a Soil Aquifer Treatment Trial for Alice Springs, Northern Territory. Draft, Water Resources Branch, Division of Natural Resources, DIPE & CSIRO Land and Water.
To evaluate the hydraulic behaviour of infiltrated water in the subsoil and to ensure excessive groundwater mounding or perching does not occur at a 600 ML/yr scale.
Knapton A. 2004b. Alice Springs Water Reuse Scheme Soil Aquifer Treatment Project Volume 4 – Groundwater Modelling.Draft, Water Resources Branch, Division of Natural Resources, DIPE, Alice Springs.
To predict hydraulic response of a 600 ML/yr SAT scheme with respect to storage, mounding and recoverability of the infiltrated water, identify the key parameters that may constrain the success of SAT and to identify future investigations required.
Pavelic P, Mucha M, Barry K, Dillon P and Hanna J. 2004. Laboratory Column Study on the Effect of Wastewater Quality on Soil Clogging During Soil Aquifer Treatment.Draft, CSIRO Land and Water
To define the water quality criteria and hence the minimum pretreatment required for recycled water from the WTP, that will allow 600 ML/yr to be recharged in basins that are of an acceptable scale.
Jeuken, M. 2004. A Hydrogeological Study of the Surficial Aquifers of South Alice Springs. Honours Thesis, School of Chemistry, Physics and Earth Sciences, Flinders University, SA.
To develop a conceptual model of the surficial aquifers south of Alice Springs, at the site of the proposed SAT scheme and to measure the rate of contaminant removal that currently occurs through land based wastewater disposal.
Lennartz R. 2005. Soil Aquifer Treatment - AZRI Soil Investigation. Land and resource Assessment, DIPE.
To establish baseline soil properties and to evaluate the basic geotechnical features to determine which areas may be suitable for storage, infiltration and recovery of recycled water.
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Report Purpose Knapton A, Jolly P, Pavelic P, Dillon P, Barry K, Mucha M and Gates W. 2004b. Feasibility of a Pilot 600 ML/yr Soil Aquifer Treatment Plant at the Arid Zone Research Institute. Water Resources Branch, Conservation and Natural Systems, DIPE Technical Report No. 29/2004.
Presents a conceptual design of a SAT system operating at AZRI, receiving tertiary treated recycled water from the WSP at a rate comparable to an annual total of 600 ML.
Crassweller C. 2004. An Archaeological Survey for the Proposed Alice Springs Water Reuse Project. Report prepared for the Power and Water Corporation.
To report on results of archaeological survey undertaken in the areas to be disturbed, to ensure that recommendations from the Office of Environment and Heritage are carried out and to recommend any mitigation procedures that may be need to protect archaeological or historic sites and objects located during the survey.
DBIRD. 2004. Survey of Culturally Significant Trees in the Proposed Horticulture Site of AZRI. Unpublished report.
To assess and report on significant tree species within the proposed horticultural development site, so as to allow incorporation of stands into horticultural layout plan.
In addition to the above, a number of previous studies have been undertaken into hydrogeological conditions and groundwater quality of the Alice Springs
region as well as options for water and recycled water management and reuse. These provide important baseline information and are listed in Table 3.
Table 3: Previous Background Research Reports Report Purpose Berry K. 1991. Monitoring Development Alice Springs Commonage. Power and Water Authority, Water Resources Branch, Alice Springs, NT Report No. 02/1991A.
To develop and understanding of the geology and hydrogeology of the Commonage area and review and report on groundwater monitoring requirements, because of concern about wastewater from Ilparpa Swamp and irrigation at Blatherskite Park seeping into groundwater drinking water aquifers.
Berry K. 1992. Alice Springs Town Basin Water and Salt Balance Studies. Power and Water Authority, Water Resources Branch, Alice Springs, NT Report No. 02/1992A.
To establish a water and salt balance and groundwater flow model for the aquifers of the Alice Springs Town Basin
Jolly P, Chin D, Prowse G and Jamieson M. 1994. Hydrogeology of the Roe Creek Borefield. Northern Territory Power and Water Authority Report No. 10/1994A
To investigate the characteristics of the Roe Creek Borefield.
Quinlan T and Woolley DR. 1969. Geology and Hydrology, Alice Springs Town and inner Farm Basins, Northern Territory. Bureau of Mineral Resources, Geology and Geophysics, Department of National Development Bulletin 89.
To undertake a geophysical survey and drilling programme to investigate the occurrence of groundwater and to construct production bores for the town water supply.
Stevens BG. 1986. Arid Zone Research Institute RN620 Bore Replacement Investigation Jan 1985 – Jun 1986. Water Resources Division, Department of Mines and Energy Report No. 22/1986.
To drill, construct, develop and test pump a replacement bore capable of yielding between 9 and 12 L/s in the vicinity of the horticulture site, power and pipelines.
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Report Purpose Dames and Moore. 1987. Alice Springs: Assessment of Environmental Effects of Existing Sewage Treatment and Disposal, and Means of Overcoming Adverse Effects.Report prepared for Northern Territory Water Authority.
To provide an assessment of the performance and environmental impacts of the sewage treatment ponds at the Alice Springs Commonage and to review previous recommendations for overcoming shortfalls in the treatment capacity and environmental acceptability.
Acer Vaughan. 1990. Report on Town Basin Water Use and Reclaimed Sewage Effluent Use. Report prepared for the Power and Water Authority.
To determine the feasibility and costs of reducing the water demand from Roe Creek Borefield by increasing use of the Town Basin aquifer and by using recycled water to alleviate soil salting problems in Alice Springs and to investigate options for achieving this.
Emerson WW and Weissman D. 1997. Compaction of Soils Irrigated with Bore Water in Central Australia. CSIRO Land and Water technical Report 12/97.
To determine the cause of development of shallow dense layers of soils in irrigated areas and how to manage the physical restraints these conditions impose on plant growth.
Sinclair Knight Merz. 2000a. Alice Springs Urban Water Management Strategy: Sewage Treatment and Effluent Management Report. Report prepared for the Power and Water Authority.
To identify and evaluate options for the long-term development of Alice Springs’ water supply and sewage systems.
Sinclair Knight Merz. 2000b. Alice Springs Urban Water Management Strategy: Aquifer Storage and Recovery Feasibility Report.Report prepared for the Power and Water Authority.
To identify and assess the feasibility of providing additional storage for recycled water using underground storage methods and recovery of the stored recycled water for reuse.
Hostetler SD. 2002. Recharge to the Amadeus Basin Around Alice Springs, Central Australia. Water Program, Bureau of Rural Sciences, Canberra.
To determine the effect of 25 years of heavy extraction of groundwater from the Roe Creek Borefield.
Varidel M. 2003. Alice Springs Effluent Irrigation System Review. Unpublished report prepared for Power and Water.
To determine a clear strategy for managing effluent from the Alice Springs Waste Stabilisation Ponds in the future, addressing current guidelines for water reuse and public health issues, efficiency of irrigation systems and potential changes to current irrigation practices.
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In addition to the studies listed above, there are a number of detailed reviews of water reuse schemes around the world, including elsewhere within Australia (e.g. De Araujo et al., 2003; Radcliff, 2004). These reviews provide descriptions of desirable site characteristics for SAT schemes, potential issues which may arise, or have arisen in the past, and methods of management of these issues.
Outline of Water Reuse Project
Preliminary Treatment of Wastewater Improving the quality of wastewater from the WSP is planned through the use of a Dissolved Air Flotation (DAF) system, or equivalent, to significantly reduce suspended solids (largely in the form of algae) and a disinfection process to significantly reduce the potential pathogen concentration. The DAF plant is proposed to produce up to 12 ML/day of recycled water for reuse. The recycled water quality is proposed to be suitable for unrestricted reuse in accordance with appropriate national water quality guidelines after Soil Aquifer Treatment (SAT) and sub-surface storage. The treatment infrastructure required for this task will be constructed adjacent to the WSP. An 8 km pipeline to transport the tertiary treated recycled water to AZRI for SAT has been constructed. The proposed works for the development of the treatment plant and transfer pipeline are not included in the scope of this PER.
Recharge via Soil Aquifer Treatment Technology SAT is a proven technology for the treatment, storage and recovery of recycled water. It is capable of producing a range of water qualities, which, in some cases, can be used for direct drinking water use. SAT involves the process of geopurification by allowing recycled water to infiltrate through the unsaturated zone (refer to Figure 1) using cyclic wetting and drying cycles. This is believed to provide conditions that are more conducive to both the treatment and recharge than could be achieved through the continuous ponding of water. Treated water will be transferred via pipeline to the SAT site at AZRI, where it will enter several shallow basins, known as infiltration basins. The influent recycled water will be intermittently ponded in the infiltration basins, with wetting and drying cycles of days to several weeks duration depending on site characteristics. As the infiltrate moves to the watertable below the basins, the soil acts as a natural treatment process (filter) to reduce the physical, chemical and microbial constituents of the infiltrating water. Treatment also occurs while the water moves through the aquifer in the saturated zone. Treatment occurs through filtration, adsorption onto soil of inorganic and organic substances and removal through in-situ reactions or degradation by in-situ microorganisms. Adsorption is the process whereby metallic ions and some pathogens are removed or taken up by soil particles.
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Figure 1: Schematic Depiction of Soil Aquifer Treatment (Source: Knapton et al., 2004b)
The constituents present in recycled waters may include: • Suspended solids (particulates); • Nutrients; • Inorganic pollutants (metals); • Bulk and trace organic pollutants;
and/or • Pathogenic microorganisms, such as
viral particles and bacteria. Cyclic wetting and drying produces recurring aerobic (with oxygen) and anaerobic (without oxygen) conditions immediately below the infiltration basins and uses the soil as a natural filter to reduce concentrations of contaminants in infiltrating water through physical, chemical and microbial processes. Thus: • Suspended solids can be filtered out; • Transport of inorganic and organic
pollutants can be retarded through adsorption on the soil matrix;
• Organic pollutants can be degraded and decomposed by soil micro-organisms; and
• Pathogenic bacteria and viruses are attenuated through processes of adsorption, predation by indigenous bacteria and exposure to hostile environments.
Use of SAT Technology Elsewhere Soil-Aquifer Treatment has been widely applied, particularly in parts of the USA and the Middle East since the 1970s, and has been shown in a number of cases to be an effective technique for storing, treating and recovering a diverse range of recycled water qualities. Comprehensive reviews of the experience gained from these operations in recent decades are available in works by National Research Council, (1994) and Bouwer (2002). SAT projects such as the Flushing Meadows Project near Phoenix, Arizona and the Dan Region Project in Israel have been operating for 25 years. These and other projects have been documented as having soils and water table depths comparable to those at the AZRI site. A summary of the systems established elsewhere, including in Arizona, is attached as supporting documentation (Appendix 2). The southern portion of Arizona has a climate very similar to Alice Springs and has had problems associated with an increasing demand for water and declining groundwater levels. Demands for fresh water, widespread acceptance of artificial recharge for water supplies and an appropriate regulatory environment have combined to create conditions for SAT to become an accepted and standard approach for return of recycled water to the
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environment in the region. SAT has proved very effective in treating recycled water to quite high quality standards, such that direct human contact with the product waters and reuse for drinking water is possible. Officers from Power and Water, DIPE and CSIRO who are involved in this project have visited a number of these schemes to assess their applicability to conditions present at Alice Springs. A very similar scheme to Alice Springs Water Reuse Scheme is the Dan Region SAT Project located in Israel. Whereas many of the SAT schemes located in the USA require a higher level of wastewater pre-treatment to enable recharge of groundwater aquifers utilised for drinking water purposes, the Israeli SAT scheme is used to produce water for non-drinking irrigation purposes as proposed for the AZRI site. This SAT scheme has been successfully in operation for almost 30 years and processes approximately 100,000 ML/year, over two orders of magnitude greater than proposed for the initial SAT scheme. A comprehensive description and assessment of key existing SAT schemes operating in the USA titled ‘An Investigation of Soil Aquifer Treatment for Sustainable Water Reuse’ has been prepared by Fox et al. (2001). The objectives of this major study included: • Evaluation of the sustainability of SAT
to avoid any accumulation of compounds of concern in the sediments or deterioration of local groundwater;
• Effective outcomes for wastewater pre-treatment, SAT site operation and the recovery of groundwater after infiltration and aquifer storage for recycled water reuse; and
• An increased understanding of the effectiveness of SAT processes and how this information can be used to design operate and regulate SAT systems.
Outcomes from this study comprised:
• Wastewater pre-treatment, which determines the quality of recycled water applied to percolation basins, is a key factor that can be controlled as part of a SAT system. The extent of pre-treatment undertaken has a direct correlation to impacts upon existing groundwater quality and the suitability of the recharged groundwater for reuse. Recycled water quality also directly impacts the design, operation and effectiveness of SAT schemes;
• SAT design and operation must take into account the site characteristics, specifically near surface soil conditions and underlying geology and groundwater. Once site conditions have been adequately characterised, the only significant design variables to be considered are the number and aerial extent of infiltration basins and the floor depth;
• Importantly, the nature of two key site characteristics did not appear to be significant factors in the successful treatment of recycled water; o The thickness of the vadose or
unsaturated zone between the infiltration basin floor and underlying groundwater or perched zones; and
o Infiltration rates through near surface soils and the vadose zone, even where they decrease during the wetting cycle; and
• Operation of SAT schemes plays a very important role in treatment outcomes and maintaining acceptable infiltration rates. The use of wetting and drying cycles appears to provide the most effective management tools for both these issues. Existing SAT facilities use a range of wetting and drying cycles that have been adapted though experience to best take advantage of the site characteristics and maximise the efficiency of the SAT infrastructure. Detailed monitoring, at least during the initial stages of SAT operation, and a flexible management approach is critical to the long term successful operation of SAT schemes.
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Previous experience with the disposal of recycled water in basins has occurred in Western Australia. Ho et al. (1992) studied the fate of contaminants in infiltrating recycled water where sandy soils were amended with bauxitic red mud along with unamended calcareous sand. Most recently, Toze et al. (2002) reported on the results of a field study at Halls Head where secondary treated recycled water is disposed of in infiltration basins that recharge the shallow groundwater. The two-year study by Toze et al. (2002) considered the efficacy of newly installed recovery bores to provide irrigation quality supplies by considering the fate of chemical and microbial contaminants. It demonstrated that the recovered water quality, with relatively short retention times (24 days), was suitable for irrigation with negligible associated health or environmental risks.
Water Banking Water banking involves depositing water in the ground via some form of artificial recharge, such as through infiltration or direct injection using bores. The water is then stored or ‘banked’ in an aquifer system and can then be recovered as needed by pumping from groundwater extraction bores. Use of groundwater for a wide range of water banking purposes is common throughout Australia and internationally. Key issues to be taken into account when considering the use of water banking includes: • Regulators and professional standards
typically take the approach that recharge water for banking should be at least of equal quality to the existing groundwater and that the recognised beneficial uses of the aquifer system should not be adversely impacted;
• The extent and nature of existing groundwater users. Their rights to water resources as well as the potential to lose banked water for unintended purposes need to be considered carefully; and
• Potential impacts upon associated surface water and groundwater quality and flows. Uncontrolled or poorly managed water banking has the potential to commence or increase discharge of poorer quality groundwater into adjacent aquifers or surface water systems as well as result in near surface water logging.
The benefits of SAT and water banking are: • The water can be treated to a relatively
high level, depending upon the quality of recycled water provided;
• The volume of water that can be stored can be significantly greater than ‘practical’ surface structures such as open ponds and large concrete or steel tanks;
• The water is stored with no evaporative losses or ongoing adverse changes, such as algal growth that may occur in surface storages;
• The length of the wetting/drying cycles can be used to control the breeding of mosquitoes in infiltration basins; and
• There are no issues with over-loading of the system, hence no major odour issues.
In the absence of established guidelines and processes, project proponents and regulators have found it difficult to strike an appropriate balance between protection of water resources and the significant benefits that can be obtained through use of water banking through SAT and other groundwater recharge mechanisms. Typically, for most Australian jurisdictions, each project is considered on its merits on a case by case basis. A current example of potentially complex issues associated with water banking is the Bolivar Wastewater Treatment Plant and Virginia Irrigation Supply project located near Adelaide. In addition to providing treated recycled water directly for horticultural irrigation purposes, a component of the project is the water banking of excess water through direct injection into an underlying limestone
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aquifer for subsequent recovery during dry weather seasons. A range of sources have indicated that trials for this water banking and recovery project have proved positive from a technical perspective. The process to obtain approval for a full scale water banking operation, however, has been delayed as relevant regulators assess the current and likely future beneficial uses for the aquifer as a whole and potential impact from injection of treated recycled water. Essentially the issues centre on the fact that the proposed water banking aquifer extends well beyond the nominal irrigation area and is considered to have a potential beneficial use for drinking water at least in certain areas. Regulators need to decide whether the potential overall beneficial use of the aquifer should take precedence or if it is acceptable to separate the immediate irrigation area from the larger aquifer beneficial uses to enable localised recycled water recharge for irrigation purposes.
Water Reuse It is envisaged that the initial reuse of the recycled waters will be for horticultural enterprises located within the AZRI site. However, reuse of the recycled water is also proposed for Blatherskite Park and other potential users along the pipeline route. This will have the benefit of improving the quality of water being supplied to Blatherskite Park under existing arrangements and there will also be the benefit of a reduced usage of the Roe Creek Borefield water, should other users substitute use of drinking water for recycled water. The establishment of a horticultural venture using up to 1,000 ML per annum of recycled water via a ‘public / private’ partnership with a selected horticultural company is the subject of current DBIRD negotiations and a preferred horticulturalist has been identified for consideration by Government. Interest in undertaking horticultural enterprises has also been expressed by commercial horticulturalists and indigenous communities in the area, where this option would be pursued in
accordance with the DBIRD Bush Foods Industry Development Plan and initiatives of the adjacent Desert Knowledge Precinct. While this partnership would account for the vast majority of the water to be recycled, additional land and water is expected to be available for further projects and other small-scale users.
Legislative Control There are five main instruments to manage potential environmental impacts associated with this scheme, comprising legislative controls and formal agreements: • EMPs for the operation and
construction of the SAT and horticultural schemes have been prepared, to provide detailed management strategies for actual and potential impacts. The EMPs refer to relevant legislation, set performance targets, provide monitoring guidelines to measure the effectiveness of environmental management strategies and describe contingencies in the event that monitoring shows poor environmental performance;
• Recycled water recharge and subsequent recovery are the subject of licensing and conditions, controlled under the Water Act 1992 and the Public Health Act 1997. These instruments will drive the extent of ‘water banking’, recovery of ‘banked’ waters, and the use of these recovered waters;
• Land Tenure Agreements will determine appropriate uses and associated leasing terms for access to land at AZRI;
• Sale of Recycled Water Agreements will detail access requirements, costs, volumes and conditions of use for the recycled water; and
• Legislation – the significant Acts relevant to the site and which will need to be complied with are: o The Water Act 1992;o The Public Health Act 1997;
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o The Soil Conservation and Land Utilisation Act 1978;
o The Heritage Conservation Act 1991;
o The Planning Act 1999;
o The Weeds Management Act 2001;
o The Commonwealth Environment Protection and Biodiversity Conservation Act 1999;
o The Aboriginal Sacred Sites Act 1998; and
o The Waste Management and Pollution Control Act 1998.
The PER is being prepared in compliance with the Environmental Assessment Act 1994.
Water Act All regulatory requirements of the Water Act 1992 will be adhered to. Advice has been sought from the Controller of Water Resources in relation to: • The regulatory instruments to govern
the operation of the SAT recharge basins; and
• The overall management of the augmented groundwater source with particular regard to appropriate buffer zones for extraction regimes.
Public Health Act The Department of Health and Community Services (DHCS) has been consulted in relation to ensuring the use of recycled water does not have any adverse affect on public health. Under the auspices of the Public Health Act 1997, all reuse projects utilising recycled water require DHCS endorsement and approval. Such approvals prescribe mechanisms to negate adverse impact to public health arising from exposure to recycled water and associated elements including soil contact and aerosol exposure.
Soil Conservation and Land Utilisation Act The Soil Conservation and Land Utilisation Act 1978 provides for the prevention of soil erosion and for the conservation and reclamation of soil. The Act provides the tools to direct a property owner to undertake rehabilitation works should activities result in soil erosion.
Heritage Conservation Act Under the Heritage Conservation Act 1991 all prescribed archaeological places and objects are protected, whether they have been recorded or not. It is an offence under the Act to disturb, damage, destroy or carry out works on these places and objects without written consent.
Planning Act The Planning Act 1999 sets out the regulatory framework for land use planning and development, using instruments such as the NT Planning Scheme and the Development Consent Authority. It ensures that control of the use and development of land is appropriate and orderly and includes a development approval process and enforcement capabilities.
Weeds Management Act The Weeds Management Act 1992 provides for the declaration of certain weed species which must be controlled and provides a framework for weed management. Prevention of weed spread and community involvement in the development of weed management plans are important aspects of this framework.
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Environment Protection and Biodiversity Conservation Act The project will not impact on any matters of national environmental significance, as listed under the Environment Protection and Biodiversity Conservation Act 1999.Matters of national environmental significance include: • World heritage properties; • Ramsar wetlands of international
importance; • Nationally threatened species or
communities; • Migratory species protected under
international agreements; • Nuclear actions; and, • The Commonwealth marine
environment.
Aboriginal Sacred Sites Act The Aboriginal Sacred Sites Act 1998 establishes procedures for the protection and registration of sacred sites, providing for entry onto sacred sites and the conditions to which such entry is subject, as well as establishing a procedure for the avoidance of sacred sites in the development and use of land. Agreement will need to be reached between custodians of sacred sites and persons performing or proposing to perform work on or use land comprised in or in the vicinity of any sacred site. Such an agreement will provide an appropriate means of site avoidance and the protection of any sacred sites.
Waste Management and Pollution Control Act The project does not required formal approval under the Waste Management and Pollution Control Act 1998. However, the Act imposes a general environmental duty of care to manage the project such that reasonable and practicable measures are taken to prevent or minimise any pollution or environmental harm and reduce the amount of waste generated.
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DETAILED DESCRIPTION OF PROPOSAL Location The proposed SAT and horticultural schemes are to be located at AZRI, 10 km south of Alice Springs in a region referred to historically as the Outer Farm Basin (Figure 2). The property is bounded to the north by the Todd River, to the south by Colonel Rose Drive, the Stuart Highway to the west and rural residential blocks to the east.
The AZRI site shows little topographic relief (<10m) with elevations grading from 558 m AHD in the northwest to 546 m AHD in the southeast (Figure 3). The site is dissected by two ephemeral drainage systems, St Mary’s Creek to the west and an overflow channel of the Todd River through the centre of the property.
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Figure 2: Location of Project Area.
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Figure 3: Topography and Drainage of the AZRI Site.
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Climatic Considerations The climatic conditions in Alice Springs typically exhibit a 200C variation each day. During the winter months of June to August the minimum temperature is around 00Cand the maximum around 200C. In the summer months, daily temperatures will typically fluctuate between 20 to 400C. The greatest use of water and the highest production of wastewater sent to sewer occur during the winter months when tourist numbers peak and
average rainfall is at its lowest. This coincides with low evaporation from the WSP. Consequently, excess wastewater flows from the WSP to Ilparpa Swamp. This trend is depicted in Figure 4. The Alice Springs Water Reuse Scheme will further treat these overflows for use on horticultural developments or storage underground until required in the summer months.
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Figure 4: Mean Monthly Rainfall, Evaporation and Waste Stabilisation Pond Overflows in Alice Springs. (Source: Power and Water, 2004)
Land Tenure
Tenure Arrangements The proposed works are to occur at the AZRI site, which is located on Vacant Crown Land, specified as Lot 800, Town of Alice Springs, NT Portion 427. DBIRD currently manages the land on behalf of the Crown. The current tenure provides a timeframe for renewal of land use options but there is no
statutory timeframe for DBIRD use of this land. The focus of AZRI is to advance research and development and promote primary industry initiatives that will encourage economic growth in Central Australia. For this reason, the AZRI site is an appropriate location to support the establishment of the Alice Springs Water Reuse Scheme.
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Under the Alice Springs Land Use Structure Plan 1999 (DIPE, 1999), the AZRI site is allocated to Community and Special uses. It specifically allows for:
the development of complementary research facilities in the vicinity of the Arid Zone Research Institute and the CSIRO.
The Alice Springs Land Use Structure Plan supports the promotion of Alice Springs as a centre of desert knowledge and research and innovations associated with this.
Horticulture Lease Arrangements It is proposed that the private horticultural partner will enter into a lease arrangement with DBIRD. The lease will include development covenants, which, if met, will have the option for being altered. For example, the lease may extend from an initial two year to a 20 year lease. If the development covenants are not met, the land would be forfeited and revert back to the Crown. Lease renewal is at the discretion of the Minister for Lands and Planning. Advice about such issues as appropriate land uses can be provided to the Minister via Government. The private horticultural partner will be required to submit a development application, which will be supported by the Construction and Operation Environmental Management Plans being prepared under the PER.
Land Use Zones The Alice Springs Town Plan 1992 (DIPE, 2004) regulates the use and development of land and provides guidance for appropriate land uses within the Alice Springs township. Land within a zone described in the Alice Springs Town Plan may only be used in accordance with this permitted land uses. If a proposed land use is not a permitted use under the Alice Springs Town Plan, consent for this land use may be sought from the Development Consent Authority (DCA). Where a proposed use of land is shown as ‘prohibited’ in the Alice Springs Town Plan,the use is prohibited. The AZRI site was initially zoned Community Purpose (CP) and Rural (R), but this was amended in 1993 and rezoned as Specific Use (SU) to permit, with the consent of the DCA, use of the land for the purpose of a citrus orchard and for ancillary purposes. The zoning of Specific Use was created to accommodate specific development projects which may not be permissible or adequately catered for in other zones. Specific Use is applied only where the ultimate development of the subject land is known. The use must be demonstrated to be consistent with existing or proposed future development in the area and be of a design compatible with the built environment of the locality. The land use zones within the vicinity of the AZRI site are shown in Table 4 and Figure 5. There is no requirement to amend the current zoning in order for the proposed SAT and horticultural schemes to proceed. However, the proposed development must be consistent with possible future land uses, including residential.
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Table 4: Land Use Zones in the Region of the Proposed SAT and Horticulture Schemes Zoning Policy B3 - Business 3 (Tourist)
Permits a mixture of compatible tourist activities, commercial or residential, while maintaining a commitment to separation of non compatible uses
CL - Community Living Permits residential accommodation on either a temporary or permanent basis. There is also opportunity for provision of non-residential supporting facilities for the social, cultural and recreational well-being of the occupants
CP - Community Purpose
Permits a variety of community uses that are compatible with surrounding uses within or outside the zone. Institution uses, such as educational, health, religious and cultural, will predominate. Residential accommodation may be permitted in association with and ancillary to the primary use
FU - Future Uses This zone applies to land where constraints such as lack of services, proximity to dominating land uses or similar influences make development of the site premature
O1 - Open Space 1 - Neighbourhood Parks
Development should be limited and consistent with the passive recreational requirements for local, public use
O2 - Organised Recreation
Development should be of a nature consistent with the recreational use of the land. Advertising should be limited to that necessary to identify the use of the land and be sited so as to minimise the impact on the locality
O3 - Regional Parks and Conservation Areas
Development should complement the existing environment so that there is minimal impact on the locality and should enhance the amenity of the area
R2 – Residential 2 (Medium Density)
Provides for multiple dwelling sites that are appropriate for the neighbourhood. All multiple dwellings are to be compatible with the scale and character of the locality. Residential subdivisions are to have regard to the design criteria contained in clauses of the ASTP
R - Rural Permits rural development with limited opportunities for urban uses. Allotments are of sufficient size to permit rural pursuits, the potential for which will be determined by local environmental conditions. Residents within this zone will be dispersed and will enjoy very few urban services and facilities
RL1 - Rural Living 1 (Close Settlement)
Permits primarily residential development with a high level of accessibility to urban services and facilities. Land within this zone is to be immediately adjacent to the urban area. There would are limited opportunities for both urban and non-urban uses. Allotments are to provide adequate separation between dwellings but will generally be inadequate for agricultural pursuits without degrading the quality of the land
RL2 - Rural Living 2 (Dispersed Settlement)
Permits a balance between residential and rural developments. Urban services and facilities will be limited and land within this zone will normally be buffered from the urban area by the RL1 zone. Allotments provide substantial separation between dwellings and opportunities for agriculture (passive) will depend on the probability of land degradation
Zone SU - Specific Use This zone is applied only where the ultimate development of the subject land is known. The use must be demonstrated to be consistent with existing or proposed future development in the area and be of a design compatible with the built environment of the locality
(Source: DIPE, 2004)
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Figure 5: Land Use Zones of the AZRI Site and Surrounding Areas.
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Native Title The Federal Court has determined that Native Title has been extinguished over the entire AZRI site. Native Title also does not apply to the groundwater, but it does apply to the adjoining land and the pipeline route. DBIRD is involved in ongoing negotiations with custodians through AAPA.
Cultural Sites of Significance No registered sites are located within the AZRI site outside of the Desert Knowledge Precinct (which has an applicable Authority Certificate). An Authority Certificate for the remainder of the AZRI site has been sought from the Aboriginal Areas Protection Authority (AAPA), under the Aboriginal Sacred Sites Act. Negotiations with land custodians have identified two hills in the northern section of the site and several large Red River Gums as sacred sites. An Authority Certificate is expected to be granted in 2005. Several land features and three tree species on the AZRI site have been identified by the Aboriginal Areas Protection Authority (AAPA) as being of cultural significance. Two landforms have been identified as having cultural significance to the local aboriginal people. These are the
aeolian dune features located in the north western portion of Sheep Paddock and the eastern portion of the River Paddock (Figure 6). Three species of tree (common names Corkwood, Ironwood and River Red Gum) have been identified as having cultural significance. Two surveys have been undertaken to identify the location of these species. Initially, mature trees (those with trunk diameters greater than a specified limit) were surveyed using GPS in the Sheep Paddock of AZRI (Figure 6). A second survey was then undertaken to include trees across the entire proposed horticultural area (Figure 7), incorporating parts of the Camel, Horse, Back, River and Sheep paddocks. Although the intent is to minimise disturbance, traditional owners are currently being consulted about any requirement to remove trees and protection of significant land forms. Where necessary, permission to disturb sites will be sought from AAPA. The proposed location for the scheme is predominantly within low scrub, with scattered clumps of large trees. Therefore, it is not expected that the ability to position this scheme and its associated infrastructure, (i.e. pipelines, ponds, power, control structures, etc.) will be limited.
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Figure 6: Location of Culturally Significant Aeolian Dune Features and Trees in the AZRI Sheep Paddock. (Source: Knapton, 2004a)
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Figure 7: Location of Significant Trees in Proposed Horticulture Site. (Source: DBIRD, 2004)
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Proposed Project Schedule The timetable for the proposed programme is provided in Table 5. Some components of this project have been commenced. This does not indicate an assumption that the project will proceed, but reflects the need to have systems in place prior to complying
with requirements to cease dry weather wastewater overflows to Ilparpa Swamp by December 2005. This early construction is a risk the proponents have recognised and accepted.
Table 5: Project Stages and Indicative Timetable
Project Stage Start Date Completion Date Wastewater Treatment Plant (DAF) 1/07/03 29/10/07
• Planning 1/07/03 16/07/04 • Construction 17/02/04 28/11/05 • Defects Liability 1/11/05 29/10/07
Pipeline - WSP to AZRI 1/07/03 21/07/06 • Planning 1/07/03 3/02/04 • Construction 4/02/04 23/07/04 • Defects Liability 26/07/04 21/07/06
Water Pumping Station 24/05/04 14/04/06 • Planning 24/05/04 3/09/04 • Detailed Design 6/09/04 26/11/04 • Construction 29/11/04 15/04/05 • Defects Liability 18/04/05 14/04/06
Water Balancing Storages 1/07/03 24/10/06 • Planning 1/07/03 31/05/04 • Construction 16/06/04 26/10/04 • Defects Liability 27/10/04 24/10/06
SAT/ASR 1/07/03 10/11/06 • Planning 1/07/03 11/07/05 • Assessment of land and water resources 2/08/04 30/09/04 • SAT Pond Trials 1/07/03 18/02/05 • Detailed Design 21/02/05 16/09/05 • Construction 19/09/05 9/12/05 • Defects Liability 14/11/05 10/11/06
Irrigation Infrastructure 1/07/03 6/10/06 • Planning - Power and Water & DBIRD
&horticulturalist 1/07/03 16/09/05 • Construction - Matilda Maid 16/05/05 7/10/05 • Defects Liability 10/10/05 6/10/06
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Completion dates are indicative and include the defects liability period associated with all construction items. It should be noted that the Wastewater Treatment Plant (DAF plant) and the Recycled Water Transfer Pipeline are not included in the scope of this PER, but have been included to provide an overall project schedule.
Proposed Location Figure 8 illustrates the location of the AZRI site in relation to Ilparpa Swamp, the WTP, existing residential areas, the Todd River, the Alice Springs Airport and township and the Recycled Water Pipeline alignment.
Figure 8: Overview of the Project Area (Source: Knapton, 2004a) The AZRI site is currently divided into a number of blocks reflecting current and past land use. These are depicted in Figure 9. The AZRI site has been used for grazing of livestock since the 1950s and
was the location for the Sentinel Herd flock for 30 years. Pasture grasses have been sown on the block over a number of years, to support livestock grazing.
Recycled Water Pipeline
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Figure 9: Existing Layout of AZRI.
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Proposed Layout
SAT Scheme Layout The site of the proposed SAT system is located within AZRI, approximately 10 km south east of Alice Springs, however, groundwater systems below the AZRI site extend well beyond this localised area. The SAT scheme layout will consist of: • Basins that may be naturally shaped,
elongated and narrow to allow preservation of environmental habitat and respect of cultural requirements. It is proposed to use natural design, topography and buffer zones to ensure the SAT basins are not visible outside of AZRI land; and
• Extraction wells, with associated access road, power and pipeline infrastructure, to be located down-gradient of the SAT basins. These will be placed at a sufficient distance to provide the required groundwater residence time, to ensure water quality standards are met.
No new buildings will be required for the SAT scheme. Figure 10 presents the conceptual layout of the proposal including monitoring and extraction bores, and the basin and recycled water pipelines.
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Figure 10: Conceptual Design of SAT Scheme
Horticulture Blocks
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The SAT basin system includes: • Two elongated basins, each 0.75 ha in
size; and • Four sub-basins within each of the
larger basins, three of which are for infiltration of recycled water. The fourth sub-basin (a surge sub-basin) is included to contain excess recycled water should the three infiltration sub-basins fill during rainfall events. The three infiltration sub-basins are each 0.16 ha in size and the surge sub-basins are each 0.2 ha in size.
The total area for infiltration is 1.5 ha, including the surge sub-basin. The entire footprint for the SAT basin system is approximately 2.16 ha, with a rectangular shape measuring 180 m x 120 m. A detailed soil investigation has recently been completed (Lennartz, 2005) to determine the final position of the infiltration basins, with respect to soil properties and recycled water infiltration. Stage 1 of the investigation enabled the identification of at least five suitable sites and Stage 2 investigations will involve more detailed investigation of two sites selected on the basis of the results from Stage 1. Preliminary results show that the nominated site (shown in Figure 10) will be suitable for siting the infiltration basins.
Horticulture Site Layout A specific layout for the horticultural site is currently being developed to take into account the distribution of soil types most suitable for horticulture and areas and trees of cultural and environmental significance. Components of the horticultural site include: • A perimeter fence to enclose the
horticulture area (100 ha) and the buildings area (5 ha);
• Five irrigation blocks, each 4 ha in size, to be developed in the first year. A further five irrigation blocks will be developed each year. These will be
placed to accommodate the desired soil types for the plants, the required buffer zones, significant Aboriginal sites, significant ecological sites and the most efficient irrigation design layout;
• Machinery and produce processing sheds within the buildings area;
• 50 m buffer zones between residential areas and sub-surface drip irrigated areas for odour mitigation;
• 50 m buffer zones between residential areas and bore pumps, irrigation pumps and cold rooms for noise mitigation;
• 100 m buffer zones between residential areas and extracted water holding dams for odour mitigation; and
• Associated infrastructure such as roads, power, telecommunications and pipelines.
Detailed Description of SAT Scheme
Treatment Selection and Location Criteria Options for the treatment of Alice Springs’ recycled water to enable reuse were assessed by Sinclair Knight Merz (2000a). Potential options were considered for three recycled water use categories: • Treatment to a standard to enable
direct reuse for drinking water; • Treatment to a standard to enable
indirect reuse for drinking water (i.e.treated reuse water is blended with standard drinking water supplies within various types of water storages prior to passing though normal drinking water treatment and testing processes); and
• Treatment to a standard to enable reuse for a range of non-drinking water uses (i.e. irrigation, recreation, commercial/industrial processing, etc.).
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Criteria utilised to assess and compare potential treatment options within each of these three categories included: • Community acceptance of recycled
water for drinking water and non-drinking water uses;
• Proven wastewater treatment technologies suitable for the climatic conditions and scale of treatment required for Alice Springs;
• Experience with recycled water use schemes elsewhere in Australia and overseas;
• Location and capacity of existing wastewater treatment infrastructure and the potential to be cost effectively utilised within future reuse schemes;
• Performance and continuation of existing recycled water use schemes (i.e. irrigation of Blatherskite Park and the tree lot);
• Maximising the volume of water available for reuse;
• Preventing or minimising the volume of wastewater discharge to Ilparpa Swamp;
• Potential impacts upon existing and future drinking water supplies sourced from groundwater;
• Existing and potential environmental impacts and possible improvements or benefits;
• Requirements for temporary storage of excess recycled water;
• Current and potential future water quality standards for drinking water and non-drinking water;
• Suitability of treated recycled water for most likely non-drinking water uses (i.e. irrigation for horticultural and municipal purposes);
• Potential to reduce generation of wastewater;
• Reuse options that could utilise recycled water without treatment through the WTP; and
• Capital and operational costs for implementing wastewater treatment, storage and supply infrastructure.
The SKM (2000a) study discounted treatment of recycled water for direct drinking water use on the basis that it was not financially feasible and would be unlikely to gain the necessary community support. A second study undertaken by SKM (2000b) focused upon the feasibility for utilising aquifer storage and recovery as part of potential indirect drinking water and non-drinking water schemes. This project undertook a preliminary assessment of each of the known suitable aquifers in the Alice Springs area to identify those that may be suitable for use in storage of recycled water as an alternative to the construction of additional open storage ponds or enclosed tanks. The study utilised a broad range of assessment and selection criteria, including: • Groundwater recovery efficiency; • Groundwater recharge efficiency; • Groundwater storage capacity; • Existing groundwater salinity; • Reaction chemistry between
groundwater and recycled water; • Aquifer degradation; • Near surface groundwater level
increase; • Proximity to existing infrastructure and
future users; • Wastewater treatment requirements; • Construction and operational costs;
and • Potential environmental impacts. For non-cost evaluation purposes these criteria were summarised into six broad potential risk headings: • Environmental impacts; • Hydrogeological uncertainty; • Potential for degraded water recovery; • Impact on current water users;
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• Impact on town water supply if treatment plant fails; and
• Potential for aquifer storage limitation. Near surface aquifers located below and adjacent to Alice Springs were excluded on the basis that the potential to exacerbate existing groundwater level and salinity issues made their use for aquifer storage and recovery unacceptable. The clear choice from this process was indirect drinking water reuse through injection of suitably treated recycled water into the Shannon Formation, which is currently utilised to provide approximately 3% of the Alice Springs drinking water supply. Other rock formations currently used for drinking water supply and near surface groundwater systems located within the Outer Farm Basin were ranked equal, but well behind use of the Shannon Formation. Based upon the findings of both SKM studies, Power and Water adopted a preferred approach to facilitate the use of recycled water at Alice Springs focused upon: • Utilising the existing WTP
infrastructure supplemented with the construction of additional treatment facilities to meet the necessary water quality standards required for reuse; and
• Utilising groundwater aquifer storage and recovery techniques for recycled water during climatic periods where recycled water supply exceeded anticipated demand.
The basis for this approach was the considerable cost benefits of maintaining use of existing wastewater treatment infrastructure and utilising natural below ground storage capacity as an alternative to construction of additional storage ponds or very large tanks. Key disadvantages recognised by Power and Water for use of the Shannon Formation for storage and recovery of recycled water included the potential loss of its current use for drinking water supplies, relatively high costs for piping, injection, extraction and required level of wastewater
treatment and issues associated with public perception regarding the proximity to other groundwater systems used for drinking water supplies. The basis for the relatively high risk score for the use of near surface groundwater systems located within the Outer Farm Basin was the uncertainty at that time over its hydrogeological capacity to be used for recycled water storage and subsequent recovery. Given the potential constraints of using the Shannon Formation and associated costs, Power and Water focused further studies on demonstrating whether use of the near surface aquifer within the Outer Farm Basin would be practical and could be managed to minimise potential environmental impacts. A key advantage identified by Power and Water for utilising the Outer Farm Basin was the potential to introduce SAT technology into the recycled water treatment process as an alternative to construction and operation of higher standard treatment plant infrastructure. Choosing the location for a SAT system is dependent on many factors, such as soil type and porosity, depth to groundwater, topography, and the quality and quantity of the recycled water. The following broad parameters are required for recycled water infiltration basins and soil aquifer recharge schemes (US EPA, 2004): • Rapid infiltration rates and
transmission of water; • No layers that restrict the movement of
water to the desired unconfined aquifer for storage and subsequent recovery;
• No expanding-contracting clays that create cracks when dried that would allow the recycled water to bypass the soil during the initial stages of the flooding period;
• Sufficient clay and/or organic-rich sediment contents to provide large capacities to adsorb trace elements and heavy metals, as well as provide surfaces on which micro-organisms can decompose organic constituents. The cation exchange capacity of clays also provides the capacity to remove
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ammonium ions and allow for subsequent nitrogen transformations; and
• A supply of available carbon that would favour rapid denitrification during flooding periods, support an active microbial population to compete with pathogens and favour rapid decomposition of introduced organics (Fox et al., 2001; Medema and Stuyfsand, 2002; Schmidt et al., 2002). Organic material in the recycled water will be a carbon source.
After the applied recharge water has passed through the soil zone, the geologic and sub-surface hydrologic conditions control the sustained infiltration rates. The possible options for the location of a SAT scheme within the Outer Farm Basin was limited to the AZRI site on the basis of the following: • Proximity to proposed irrigated
horticultural areas – AZRI selected as preferred site;
• Previous groundwater experience and studies have identified that the near surface groundwater systems in the Outer Farm Basin are highly variable and inconsistent, except for an in-filled deeper former river channel, termed a palaeochannel that had been identified crossing the AZRI site. Similar palaeochannel structures form the key groundwater flow, storage and extraction locations in near surface aquifers located below and adjacent to Alice Springs;
• Availability of suitable vacant land with clear land title; and
• The need for a buffer between adjacent land owners such as residential and commercial properties and the Airport.
Within the AZRI site, the key factors for establishing an approximate location for the SAT scheme comprised: • Estimated location of the
palaeochannel feature; • Avoiding proposed irrigation areas;
• Providing a suitable buffer to adjacent rural residential properties; and
• Existing environmental and cultural considerations within AZRI.
SAT Design Criteria Key design criteria for the scheme as a whole were based upon community and health expectations to cease use of Ilparpa Swamp for excess wastewater disposal and maximise the value and reuse of scarce water resources such as recycled water. Specific criteria included: • Prevention of mosquito breeding; • Treatment and storage of sufficient
water to meet horticultural project objectives;
• Treatment of water to meet health requirements for reuse; and
• Treatment and management of seepage water to ensure other groundwater users or soil salinity was not impacted.
Basins generally consist of bermed, flat-bottomed areas of varying sizes and shapes. Basin infiltration rates may sometimes be enhanced or maintained by creation of ridges within the basin. The advantage of ridges within the basin is that materials that cause basin clogging accumulate in the bottom of the ridges, while the remainder of the ridge maintains high infiltration rates. Final basin design for the AZRI site is still under consideration. Best practice in basin design requires: • Wetted surfaces of the soil to remain
unclogged, • An appropriate surface area to
maximise infiltration; and • A high quality of recycled water
entering the basins, to allow rapid infiltration.
Operation of the SAT basins commonly involves a wetting and drying cycle with periodic cleaning of the bottom used to prevent clogging. Drying cycles allow for
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desiccation of clogging layers and re-aeration of the soil. Cycle length is dependent on both soil conditions and the distance to the groundwater table. This is determined through field-testing on a specific site. Cyclic wetting and drying helps to maintain high infiltration rates and allows microbial populations to consume organic matter. It also helps reduce levels of microbiological constituents in the recycled water. Re-aeration of the soil also promotes nitrification, which is a prerequisite for nitrogen removal by denitrification. Periodic maintenance by cleaning of the bottom may be done by deep ripping of the soils, by scraping the top layer of soil or removal of the deposited organic materials. Deep ripping sometimes causes fines to migrate to deeper levels where a deep clogging layer may develop and is used only irregularly in most situations. Another advantage of cyclic wetting and drying is the elimination of mosquito breeding issues. It is expected that a seven day cycle will prevent mosquito larvae of problem species from hatching. The soils, geology and hydrogeology of the AZRI site have been identified as being highly suitable for SAT from comparative assessment with other SAT schemes and field studies. Two dominant shallow soil types have been recorded on site; ‘silty sands’ and ‘gravelly sands’. The silty sands are the dominant soils in the areas investigated and the gravelly sands are found along ephemeral drainages. In the areas of silty sands there appears to be a good balance between the coarser textured soils needed for high infiltration rates and the finer textured soils needed for contaminant adsorption and removal. The geology of the site consists of Quaternary silts, sands, clays and gravel overlying Tertiary clays and sandy clays. An in-filled palaeochannel feature (an ancient water channel or stream bed which has been covered by materials laid down by subsequent geological processes) incised into the Tertiary clays, 400 m wide and at least several kilometres long, has
been located at between 17 to 30 m below ground surface. The infill sediments of this feature show high permeability and storage characteristics making it the most prospective area for siting SAT, however the precise location within this area is the subject of a recently completed localised soil survey (Lennartz, 2005). The exact location of the SAT basins within the nominated site (refer to Figure 10) will be selected based on the following criteria: • The presence of silty, sandy soils,
which are preferred for the basin floors. Infiltration basins require permeable soil for high hydraulic loading rates, yet the soil must be fine enough to provide sufficient soil surfaces for biochemical and microbiological reactions, which provide additional treatment to the recycled water. Some of the best soils are in the sandy loam, loamy sand, and fine sand range;
• The location of the palaeochannel feature, as the basins must overly the palaeochannel;
• The amount of tree cover, as it is preferred that the basins are located in areas with negligible tree cover, to minimise disturbance to culturally sensitive trees species;
• The proximity to the preliminary basins established during field investigations, to maximize the benefits of the existing monitoring infrastructure; and
• The proximity to the delivery pipeline, as costs will be reduced if the basins are in close proximity to the pipeline.
The chosen location is fully fenced, which will prevent livestock from entering the basins and causing erosion and possible basin floor compaction.
Infrastructure Requirements The infrastructure requirements for the proposed SAT scheme are as follows: • Pipeline from WSP to AZRI site
(already installed);
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• Construction of two SAT infiltration basins covering approximately 0.75 ha each;
• Access roads to SAT infiltration basins and extraction wells;
• Groundwater monitoring wells around SAT area;
• Groundwater extraction wells and pipelines for obtaining water for reuse; and
• Power and telecommunications.
Design and Engineering Details Specific design and engineering features of the SAT scheme encompass: • Infiltration requirements; • Mosquito control; • Protection of environment and cultural
items; • Overflow freeboard; and
• Underlying soil and groundwater conditions.
The design of the SAT basins was devised to allow for: • Alternative filling between two sets of
basins to provide intermittent wetting and drying (notionally seven days wetting followed by seven days drying);
• Either direct supply to each of the sub-basins with the flow being controlled by the basin water levels or by allowing gravity flow between the sub-basins controlled by spillways constructed to the operating depth of 0.3 m above the basin floor;
• Expansion of the scheme in the future as technical viability is demonstrated and demand for SAT water increases; and
• The targeting of silty, sandy soils. The proposed design parameters are tabulated in Table 6.
Table 6: AZRI Soil Aquifer Treatment Scheme Design Parameters Design Parameter Design Comments
Annual Infiltration Capacity
600 ML/year
600 ML/year selected as initial scale. Possible for capacity to increase to 1,200 to 1,800 ML/year.
Average Daily Infiltration Capacity
1.8 ML/day or 20L/s over 24 hours
Current WSP inflows average 9 ML/day. 20% generally expressed as ‘overflow’ to Ilparpa Swamp.
Storage Capacity
1,800 ML over 3 years
Based on Town Basin measurements between 2,000 to 4,000 ML total storage capacity across AZRI site.
Site Capacity
Peak Daily Infiltration Capacity
2.2 ML/day or 820
ML/year
Based on proposed basin configuration and infiltration design parameters.
Average Daily Infiltration Capacity
0.3 m/d
Design value accounts for clogging potential of recycled DAF product water of a quality defined below. Potable reticulated supply used in trial.
Specific Parameters
Influent Suspended Sediments
<30 mg/l Consistent with SA Reclaimed Water Guidelines – Class B. Present studies suggest this target may be consistent with Infiltration design target.
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Design Parameter Design Comments Influent BOD <20 mg/l Consistent with SA Reclaimed Water
Guidelines – Class B. Individual Basin Area
0.75 ha each
Area required to infiltrate a minimum of 600 ML/yr of recycled water.
Number of Basins
2 For wet/dry cycle operation and flexibility in cycle duration to accommodate airborne pest potential
Basin Depth 0.6 m Minimum to expose suitable strata Water Depth in Basins
0.3 m Maximum to limit surficial layer compaction and minimise residence time of water in pond
Wet/dry Cycle Length
7 days wet & 7 days
dry
Can be adjusted to maximise recharge or if potential mosquito issue develops
Depth to Groundwater
16 m Average across site may exceed 20 m.
Retention Time
NA Not required for indirect non-drinking water reuse. Only an issue if infiltrate migrates off-site.
Recovery Wells
Up to 11 Location to be determined
Specific Parameters continued
Recovery Rate
Up to 800 ML/yr
Expected operational rate 5L/s per bore accessing existing plus recharged storage
Groundwater Flow Rate
300-1,000 m/yr
Estimated aquifer transmissivity needs to be refined to reduce uncertainty
Regional Parameters
Site Flood Inundation
1 in 50 years
In event of flood out of Todd River, operational interruption expected to be < 2 months.
In summary, current proposals are for two basins of 0.75 ha each (1.5 ha in total). Water depth is anticipated to be 300 mm with an overall basin depth of about 600 mm. The collective application of these design parameters is expressed as a conceptual design physically illustrated as per Figure 10 shown in Section 2.6.1. This possible design scenario uses a direct controlled supply to each of three pairs of sub-basins (six in total). The basins allow for 1,600 kL/day infiltration at 0.3 m/day (600 ML/yr over a 12 month period). The basins have been designed to provide flexibility in the infiltration rate or the supply rate. As the infiltration rate decreases or the supply increases the other sub-basins can be employed to account for the short-fall in surface area of the operating basins.
The water supply to each of the basins is to be controlled by the individual basin water levels with an actuated flow valve close to the outflow point. Each of the basins will require an energy dissipater at the point of inflow to prevent erosion of the basin floor, possibly including a rock or concrete apron type structure. The basins will have a minimum depth of 0.6 meters below the surface, with the individual sub-basins having flat, horizontal floors. The slope of the basin walls should be around 1:2 to reduce the erosion of the walls and to provide an easy exit for small animals which may enter the basins. Matting or waste rock material will also be required to stop erosion of the banks. The ponding depth of the basins is 0.3m.
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Whilst the proposed seven day wet/dry cycles should allow for the restoration of any decline in short-term infiltration rates, some residual clogging will occur over the longer term. This will require manual intervention. Solutions to the problem include disc ploughing to break up the clogging layer, or scraping and removal of the clogging layer. Access points should also be considered for the maintenance of basin floors and sides. The proposed SAT will have a minimum ‘design’ infiltration capacity of 600 ML/yr. During winter months the daily temperature typically fluctuates between 4oC and 20oC(compared with summer months when the daily temperature fluctuates between 20oCand 36oC). This decrease in temperature during winter results in a three to four fold decrease in evaporative losses in the wastewater treatment processes. Consequently this period will place a greater pressure on the SAT capabilities than summer months. However, evaporative losses are a very minor component of water loss over a year (<10 m of evaporation vs >100 m of infiltration). The minimum infiltration rate with recycled water, depending on its level of treatment, is estimated to be 0.3 m/day. This rate is based on providing an allowance for suspended sediments in the recycled waters, which as yet is untested, and enables a higher degree of scheme operational flexibility than may be possible if a higher rate was adopted at this time. Based on the infiltration rates achieved elsewhere with similar soils, this figure is deemed to be a conservative estimate.
Proposed Construction Methods Proposed construction methods for the SAT scheme include: • Earthworks for basin construction,
requiring use of excavator or similar. Excess soil material could either be mounded around the perimeter or transported off-site;
• Road construction, following standard road construction methods in the Northern Territory, including measures for erosion control and dust suppression;
• Drilling for bores for the groundwater monitoring and extraction programme;
• Finalisation of pipeline construction to the SAT basins; and
• Connection to electricity supply and communication systems.
Vegetation Removal The construction of the SAT basins and associated infrastructure will require some vegetation removal. The footprint of the SAT basins is estimated at 2.16 ha and the majority of vegetation in this area will be required to be removed. Removal of significant trees will require authorisation from the Aboriginal Areas protection Authority (AAPA).
Quality of Recycled Water Entering Infiltration Basins
Salinity The potential for the SAT operation to mobilise additional stored salts within the soil profile requires monitoring but will dissipate as infiltration 'washes' these salts into the storage aquifer. Preliminary laboratory observations and field testing suggest a limited potential for this to present operational constraints to the SAT scheme (Knapton et al., 2004b). Present indications are that the existing underlying groundwater is of a similar constituent chemistry to the proposed infiltrate but has a higher overall salinity level of 1,500 mg/L. The ‘native’ groundwater appears to be derived from several sources, including the Town Basin outflow, Todd River floodouts, recycled water irrigation at Blatherskite Park, Ilparpa Swamp flows and locally occurring runoff recharge. As a result of these multiple
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sources, and the high rates of aquifer through-flow, the native groundwater quality is variable over time, yet it is generally too saline for use as drinking water at present. The recycled water will be of lower salinity, around 1,000 mg/L, and the SAT operation is unlikely to produce discernible changes to the existing groundwater quality regime other than in relatively close proximity to the SAT site itself. There is negligible overall risk for the environmental values of the Quaternary aquifer to be adversely impacted, and overall water quality improvements are anticipated. This improvement is likely to manifest itself in lower salinity in the recovered SAT water than that in the presently existing aquifer.
Contaminants The infiltration basins are designed to accept continuously over 12 months a minimum recycled water volume of 600 ML (Knapton et al., 2004b). Unpublished recent data on the quality of recycled water representative of that proposed for introduction to the tertiary treatment plant (proposed DAF and chlorination) and thence to the SAT basins was obtained from Power and Water for the years 2003 and 2004. This data is summarised in Table 7.
Table 7: Median Concentrations of Determinants in Recycled Water Exiting the Alice Springs Waste Stabilisation Ponds 2003-2004. Determinant Units Concentration Total Suspended Solids mg/L 85 Volatile Suspended Solids mg/L 74 BOD mg/L 54 Total Dissolved Solids mg/L 1,046 E. coli CFU/100 mL 11,000 (Source: Power and Water, unpublished data) Organic Material The data in Table 7 shows that much of the Total Suspended Solids material (approximately 88%) is of a volatile nature (Volatile Suspended Solids); that is, it is organic material. This volatile component of the suspended solids is overwhelmingly dominated by algal biomass growing in the final, aerobic lagoons. Thus an estimate of this algal biomass (as dry weight) is given by the Volatile Suspended Solids concentration. Correcting this for the proposed volume of 600 ML/yr to be introduced into the SAT basins means that in the absence of solids removal (e.g. DAF plant, filtration system etc.) the annual algal biomass (or suspended organic material) introduced to these basins would be approximately 44 tonnes. Much of this would eventually settle to the bed of the SAT basins and result in an anaerobic sediment/water interface. This has several
implications for the water quality of infiltrate entering the vadose zone and aquifer storage. If these solids are removed from the final wastewater through tertiary treatment at the DAF plant prior to introduction to the basins, it is inevitable that some algal regrowth will occur in the infiltration basins and that subsequent deposition of this material will create an anoxic/anaerobic sediment/water interface. Quanrud et al.(2003), during a five year field-scale soil aquifer treatment of municipal wastewater in the south west of the USA in a climate broadly similar to central Australia, indicated that SAT could attenuate (by approximately 90%) all organic compounds of concern (including pesticides and their break down products in recycled water). Studies were conducted utilizing both mature (over 10 yr old) and new infiltration basins. Removal of
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dissolved organic carbon (DOC) was robust, averaging >90 % during percolation through the local 37 m vadose zone. The hydrophilic (most polar) fraction of the DOC was preferentially removed during SAT and removals were attributed primarily to biodegradation. Reductions in trihalomethane formation potential (THMFP) averaged 91 percent across the vadose zone profile. Variations in the duration of wetting/drying periods did not significantly affect organic removal efficiencies. Further work on understanding these issues is continuing worldwide although present studies confirm that very high levels of removal of the organic compounds of concern are possible in a SAT system. Bacteriological Indicators (E. coli) and Other Microbes The fate of micro-organisms and the ability to assure the microbiological quality of groundwater is critical to protecting public health and obtaining public and regulatory acceptance of managed ground water recharge programs. The micro-organisms of concern in groundwater are primarily viruses, as most (not all) bacterial pathogens of human concern are denatured in soil systems. The length of time that viruses and viral genetic material may persist in groundwater is important to planning and designing recharge projects and understanding the additional health protection provided by soil aquifer treatment. Where studied, virus contamination has been reported in groundwater that was, intentionally or unintentionally, recharged with recycled water. Contaminated groundwater was generally associated with use of poorly treated, sometimes non-disinfected sewage. Use of modern methods has made detection and identification of viral pathogens reasonably common, and US experience indicates that significant reductions of micro-organisms are seen in SAT areas where extensive analysis has been carried out. Potential contamination is also related to distances from the
recharge areas and whether up or down stream from the soil aquifer treatment sites (Fox et al., 2001) More recent US studies in environments similar to Alice Springs confirm that soil aquifer treatment of recycled water will substantially remove viruses (Quanrud et al., 2003), although these studies did not indicate total removal in all instances. Inevitably, significant concentrations of the bacteriological indicator E. coli will be present in the recycled water entering the SAT infiltration basins. Some strains of E. coli can themselves be pathogenic but their presence in water or recycled water also indicates the possibility of the presence of other potentially more serious pathogens. Some pathogens (protozoan, helminth, bacteriological or viral) will likely be present in the SAT infiltration basins at certain times sourced either from the recycled water proper or due to direct inoculation of the storages by birds etc. that will likely frequent these basins. There are a large number of studies available that demonstrate the removal and inactivation of E. coli through soil columns. Kowal (1982) found that bacteriological groundwater pollution was associated with land application of minimally treated wastewater on to soils with high percolation rates resulting in rapid infiltration. A more recent study by de Araujo et al. (2003) found that soil filtration removed 98% of faecal coliform bacteria from raw untreated wastewater. Pre-treatment of the wastewater used in the proposed SAT scheme and the design of the infiltration basins will render bacteriological contamination of the storage aquifer highly unlikely. Transport of viral particles through the soil column is only moderately understood but Chu et al. (2003) found that soils with elevated concentrations of metal oxides displayed enhanced viral sorption and inactivation of the subject viruses in the soil column. Groundwater detention times of 50 days have been cited as adequate to achieve protection of human health from pathogens (Knapton et al., 2004b).
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Endocrine Disruptors The issue of trace amounts of substances potentially detrimental to the environment and to humans has received increasing attention since the early 1960s. Wastewater treatment systems may potentially carry small amounts of both pesticides and pharmaceuticals, as the waste system may be used to both dispose of these products (inadvertently or sometimes deliberately) and as excreted products from the human body. Viruses and bacteria are also excreted and present in wastewater. Of increasing interest has been the waste products with oestrogenic activity and commonly referred to as endocrine disrupting products. Endocrine disrupting chemicals (EDCs) are a group of emerging contaminants that are hormonal in action and that may affect the endocrine function of exposed organisms. At present the testing of individual compounds is very much at the research and development stage. It is likely that in the future EDC evaluation will be conducted by assay techniques rather than individual compound determination. A number of oestrogenic compounds classified as EDCs are natural although non-natural forms are becoming a health issue in water and wastewater treatment systems. Many EDC compounds have however been found to degrade rapidly in the sub-surface due to their affinity for soil organic material (Verstraeten et al., 2003). At the present state of knowledge in respect of EDCs, these compounds are not expected to be significant to the viability of the proposed SAT project. Overseas, SAT systems are used in many situations where the recharge aquifers provide drinking water. The present plans for the Alice Springs SAT scheme do NOT allow for extraction of water from the recharged aquifer for drinking water, thus immediately reducing potential problems, but the need to understand the issue of these chemicals in the environment is of importance. Practical implications of the presence of these compounds in SAT schemes across
a wide variety of climate zones include (NCSWS, 2001; Quanrud et al., 2003): • Most conventionally treated
wastewater contains oestrogens and oestrogen mimics. The human and ecological health implications of exposure to such residuals are uncertain;
• Secondary treatment can effectively attenuate, but not eliminate, oestrogenic activity in recycled water. The efficiency with which oestrogenic compounds are attenuated is probably related to the efficiency of biological treatment processes;
• Ephemeral streams that are sometimes dominated by recycled water may be especially prone to residual oestrogens in recycled water;
• Percolation of secondary treated recycled water through sediments (e.g. SAT type schemes) is an effective barrier to transport of oestrogens and oestrogen mimics. The depth of the vadose zone may be a factor in the efficiency of removal of oestrogenic activity during infiltration. The mechanism of removal of oestrogenic chemicals during infiltration (adsorption versus biodegradation) has not been established, although the removal of bulk organics is primarily biochemical;
• Oestrogenic compounds are also attenuated by lateral transport through saturated sediments or by storage under ground. Nevertheless, low levels of oestrogenic activity can be observed after as much as 130 m of lateral transport and storage under ground for periods of months to years. It is not yet possible to relate removal efficiencies for oestrogens to infiltration depth, lateral transport distances or time of underground storage;
• The correlation between the oestrogen IC50 and dissolved organic carbon (DOC) in secondary treated recycled water and recycled water subjected to SAT suggests that DOC is a valid
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parameter for regulating some forms of water reuse; and
• Additional work is necessary to link the results of in vitro bioassays and those of bioassays that are more directly relevant as indicators of human health effects. Without such correlations, it may not be possible to base regulations or determination of regulatory compliance on the results of in vitro bioassays. Nevertheless, these tests will continue to provide an internally consistent basis for assessment of treatment efficiency and water quality comparisons.
Detailed Description of Horticulture Scheme The horticulture scheme includes a plan to develop 20 ha per year in 4 ha operational blocks for five years, resulting in a total horticultural area of 100 ha. There is currently no plan to expand the horticultural scheme beyond this, in recognition of the trial nature of this project. Final planning of the operational blocks will be subject to detailed site planning. There will also be development of a range of basic operational infrastructure including an access road and staff car parking, office, manager’s house, fruit packing sheds and cold rooms, fuel storage, fertilizer shed, machinery sheds and related minor outside storage associated with a modern horticultural operation and internal site roads. This basic infrastructure would include utility services.
Location and Design Criteria The major site features which influence the location and design of the horticultural components are: • The soil types within the horticultural
area; the distribution of soil types will determine the location of the 4 ha horticultural plots, as well as influence decisions on soil augmentation;
• The location of culturally significant tree species; it is expected that the shape of the horticultural plots will be non-uniform, to accommodate retention of trees. Some clearing will be required and this will be determined in consultation with the Aboriginal Areas Protection Authority (AAPA);
• The location of extraction wells; in order to minimise costs, it is desirable to have the horticultural lots positioned close to the extraction wells;
• The location of existing infrastructure, such as power and water; again, in order to minimise costs, it is desirable to have the horticultural lots positioned close to existing infrastructure, although it is recognised additional services will need to be installed; and
• The distance to boundaries of the proposed horticultural area, particularly those boundaries common with residential areas and roads; although vegetated buffers will be retained, it is desirable to maximise the distance between the horticultural plots and nearby residents.
Each of these factors will be considered during the final design and layout of the horticultural scheme.
Infrastructure Requirements The infrastructure requirements for the proposed horticulture scheme are as follows: • Bitumen access road from Colonel
Rose Drive; • Staff car park – constructed with
gravel; • Fruit packing shed 20 m x 20 m; • Cold storage rooms 15 m x 20 m; • Tractor and implement shed 10 m x
20 m; • Diesel storage tank 2,000 L; • Fertiliser storage shed 10 m x 10 m; • Filter and pump shed 10 m x 5 m;
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• Manager’s house 12 m x 15 m; • Access to electricity grid; • Access to town water supply; • Access to recycled water supply; • Electric bore pump enclosure (x3); and • Electric irrigation pump enclosure (x1).
Groundwater Recovery Design and Engineering Details To harvest the infiltrated water for subsequent reuse, it is envisaged that a minimum of four to five recovery bores capable of extracting up to 5 L/s each (630-790 ML/yr) could be located within the AZRI site to intercept the infiltrated water. It should be noted that the peak demand associated with horticultural activities will, however, require up to 50 % of the annual demand to be extracted during the summer months, therefore, approximately 10 to 11 bores will be necessary to meet those peak demand periods. Present drilling and pumping results suggest that further work is required to determine the optimum location and design parameters for these extraction bores. Present indications are that these bores could be located within 200 to 300 m of the SAT pond system. It is proposed to use single extraction wells or multiple extraction bores, both of which will be screened from below the base of the palaeochannel (sump) to near the surface to provide maximum exposure to the groundwater system. Wells or bores will be sealed to prevent surface water infiltration and electric pumping systems will be used.
Horticulture Area Construction Methods Proposed construction methods for the horticulture scheme include: • Soil is prepared or planting by deep
ripping to 1 m in both directions by a large tractor;
• Water mains are dug with a small chain digger;
• Water pipes are distributed with a small tractor;
• The sub-surface dripper for irrigation is ripped into place at 0.5 m depth by a small tractor;
• Crops (grapevine, citrus etc.) are planted along the sub-surface dripper using a water jet (small tractor);
• Posts (grapevines only) are inserted along the sub-surface dripper using a small tractor with a hydraulic ram impactor; and
• Trellis (grapevines only) is distributed with a small tractor.
Construction of buildings, roads, car-park areas and connection to the electricity grid and town water supply will follow standard construction industry practices and approved materials, as approved by the Northern Territory Government and according to Australian Standards and codes, including the Building Code of Australia.
Vegetation Removal The actual area of vegetation required to be cleared is not yet known, because the final layout of the horticultural scheme is still to be finalised. However, some vegetation will be cleared within the horticultural site and for the purposes of installing new roads and firebreaks (as required), as well as for planting of crops in the 4 ha horticultural plots. Any trees which may be identified as having cultural significance may not be removed without consultation with traditional owners and approval from the AAPA.
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Quality of Water for Horticulture Use
Water Quality Guidelines for Reuse Power and Water has adopted both a ‘fit for purpose’ and ‘barrier approach’ to ensure the integrity of the water quality provided to the end users. To assist in this approach a review was undertaken of the requirements of a range of Australian and international reuse guidelines for unrestricted public access. Table 8 provides a summary of water reuse guidelines in other parts of Australia and internationally. While it is not proposed to adhere to a specific guideline for benchmarking reuse for this project, the ‘South Australian Reclaimed Water Guidelines’ are considered as the most applicable, given both the climatic similarities (particularly in northern South Australia) and the reuse
application (given the extensive use of recycled water for grape growing) in Alice Springs. Table 9 provides description of the different grades of reused water quality and Table 10 provides a summary of the acceptable uses for each class of water (Environment Protection Agency and Department of Health, 1999). It is expected that the recycled water for horticultural irrigation will be closest to Class B, based on the proposed treatment train. The proposed irrigation method of sub-surface drippers for the horticultural component and surface spray for pasture development provides further safeguards, as these methods are recommended for lower quality water.
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Table 8: Summary of Water Quality Guidelines for Water ReuseRequired Water Quality Levels
State/ Territory/ Country SS(mg/L)
BOD(mg/L)
Turbidity(NTU)
pH ThermotolerantColiforms (cfu)
Acceptable Disinfection
Environmental Guidelines for the Use ofRecycled Water, Tasmania 2002
N/S <10 2 5.5 – 8.0 ≤10/ 100 mL Microfiltration/ ultraviolet radiation/ ozonation/ chlorination
ACT Environment and Health WastewaterReuse Guidelines, ACT 1997
N/S N/S N/S 6.5 – 8.0 ≤10/ 100 mL Chlorination with ≥1 mg/L chlorine residue with a minimum contact time of30 minutes
Guidelines for Environmental Management:Use of Reclaimed Wastewater, VIC 2002
<5 <10 2 6 - 9 <10/ 100 mL Ultraviolet radiation/ chlorination/ ozonation (and helminth reduction)
NSW Guidelines for Urban and ResidentialUse of Reclaimed Water, NSW, 1992
N/S N/S 2 - 5 6.5 – 8.0 <10/ 100 mL Chlorination with 5 mg/L chlorine residue with a minimum contact time of60 minutes
South Australian Reclaimed WaterGuidelines, SA 1999
N/S 20 ≤ 2 4.5 – 9.0 <10/ 100 mL Lagooning/ chlorination/ ultraviolet radiation/ chlorine dioxide
Interim Guidelines for Reuse or Disposal ofReclaimed Wastewater, QLD 1996
≤30 ≤20 ≤ 2 6.5 – 8.5 10/ 100 mL Chlorination/ultraviolet radiation /ozonation/ membrane processes
WA No Guidelines AvailableGuidelines for Sewerage Systems: Use ofReclaimed Water, National Water QualityManagement Strategy 2000
N/S N/S ≤ 2 6.5 – 8.5 10/ 100 mL Chlorination with 1 mg/L chlorine residual with a minimum contact time of30 minutes
Title 22: California Code of Regulations,State of California 2001
N/S N/S 2 - 5 ≤ 2.2/ 100 mL Chlorination with 5 mg/L chlorine residual with a minimum contact time of90 minutes
World Health Organisation N/S N/S N/S N/S <200/ 100 mL Stabilisation ponds to achieve wastewater quality indicated, or otherappropriate treatment
Maximum <5 <10 ≤ 2 6.5 – 8.0 ≤ 2.2/ 100 mL Chlorination with 5 mg/L chlorine residual with a minimum contact time of 90 minsMinimum ≤30 ≤20 2 - 5 4.5 – 9.0 ≤10/ 100 mL Chlorination with 1 mg/L chlorine residual with a minimum contact time of 30 mins
N/S: Not Specified
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Table 9: Classes of Reuse Water
Recycled Water
Microbiological Criteria E. coli/100 ml (median)
Chemical/Physical Criteria (mean)
Typical Treatment Process Train
Class A < 10 plus specific removal of viruses, protozoa and helminths may be required Treat water to reduce the risk of infection from all types of potential human pathogens
Turbidity ≤ 2 NTU BOD < 20 mg/L Chemical content to match use
Full secondary plus tertiary filtration plus disinfection. Coagulation may be required to meet water quality requirements
Class B < 100 plus specific removal of viruses, protozoa and helminths may be required The risk associated with the possible presence of intestinal parasites and viruses in water depends on use e.g. the helminth Taenia saginata represents a risk to cattle (beef measles) and should not be present in recycled water used to irrigate pasture or for stock water for cattle
BOD < 20 mg/L SS < 30 mg/L Chemical content to match use Filter lagoon wastewater samples for analysis and determine soluble BOD Suspended solids may contain algae and need not be measured
Full secondary plus disinfection
Class C < 1,000 plus specific removal of viruses, protozoa and helminths may be required The risk associated with the possible presence of intestinal parasites and viruses in water depends on use e.g. the helminth Taenia saginata represents a risk to cattle (beef measles) and should not be present in recycled water used to irrigate pasture or for stock water for cattle
BOD < 20 mg/L SS < 30 mg/L Chemical content to match use Filter lagoon wastewater samples for analysis and determine soluble BOD Suspended solids may contain algae and need not be measured
Primary sedimentation plus lagooning or full secondary (disinfection if required to meet microbiological criteria only)
Class D < 10,000 Helminths need to be considered for pasture or fodder
Chemical content to match use
Primary sedimentation plus lagooning or full secondary
(Source: Environment Protection Agency and Department of Health, 1999)
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Table 10: Summary of Acceptable Use for Different Classes of Recycled Water Quality.
Type of Crop Irrigation Method Harvesting Controls Recycled Water Spray, flood None Class A Drip, furrow None Class B
Large surface area grown on or near the ground and consumed raw (e.g. broccoli, cabbage, cauliflower, celery, lettuce) Sub-surface None Class C
Spray None Class A Flood Dropped produce not to be
harvested Class B
Drip, furrow Dropped produce not to be harvested
Class C
Crops without ground contact (e.g. tomatoes, peas, beans, capsicums, non-citrus orchard fruit, non-wine grapes)
Sub-surface None Class D Spray Produce should not be wet
from irrigation with recycled water when harvested
Class B
Flood Dropped citrus not to be harvested
Class C
Crops without ground contact and skin that is removed before consumption (e.g. citrus, nuts)
Drip, furrow, sub-surface
None Class D
Spray Produce should not be wet from irrigation with recycled water when harvested
Class B
Drip, flood, furrow
Produce should not be wet from irrigation with recycled water when harvested
Class C
Crops with ground contact and skin that is removed before consumption (e.g. melons)
Sub-surface None Class D Spray, drip, flood, furrow
None Class C Surface crops processed before consumption (e.g. brussel sprouts, pumpkins, cereals, grapes for wine making)
Sub-surface None Class D
Any Withholding period of 4 hours before pasture used for dairy animals; alternatively dry or ensile fodder before use.
Class B Irrigation of pasture and fodder for dairy animals
Any Withholding period of 5 days before pasture used for dairy animals; alternatively dry or ensile fodder before use
Class C
Irrigation of pasture and fodder for nondairy animals
Any Withholding period of 4 days before pasture used for dairy animals; alternatively dry or ensile fodder before use
Class C
(Source: Environment Protection Agency and Department of Health, 1999)
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Salinity Present indications are that the existing groundwater is of similar constituent chemistry to the proposed infiltrate but has an overall higher salinity level of 1,500 mg/L. The influent waters will be of lower salinity, around 1,000 mg/L, hence, based on mixing of the native groundwater and infiltrate, it is expected that the recovered water will have a salinity in the range of 1,000 to 1,200 mg/L. The mixing between the regional groundwater and infiltrate will become an important operational consideration in relation to the chemical quality of recovered water at this site. It is not possible to quantify this until such time as a ‘significant’ mound of infiltrate is established as part of this preliminary SAT programme. It should be noted, that the existing groundwater cannot support a drinking water use due to their brackish TDS and it is currently considered to be of ‘marginal’ utility for irrigation use in significant quantities.
Contaminants The microbiological and nutrient quality of the infiltrate mound are expected to show significant quality enhancements over the recycled water from the wastewater treatment plant, based on comparative assessments from the literature on SAT performance. Marked reductions in nutrients and pathogens are expected to produce water comparable in quality to Class A of the South Australian Reclaimed Water Guidelines. These quality outcomes are expected to be delivered in a consistent and ongoing basis over the time scale of travel through the sub-surface system. Further works are required to confirm and refine this assessment, yet a high degree of confidence exists for such an outcome at this site. Table 11 below outlines the process-train and expected pathogen reduction achieved in each process. Quantitative data provided in terms of log removal of pathogens are based on results achieved in the NT and interstate.
Table 11: Expected Pathogen Reduction
(Source: Power and Water, 2003) Notes on contaminants and pathogen groups and their expected reduction
through the treatment train are summarised below.
Raw Sewage
Waste Stabilisation Ponds
Dissolved Air Flotation (DAF)
Filtration (optional future use)
Chlorination Soil Aquifer Treatment (AZRI)
Irrigation
Bacteria 5 log reduction
some reduction
some reduction
3 log reduction
6 log reduction
Virus 3 log reduction
some reduction
some reduction
3 log reduction
?
Protozoa 3-4 log reduction
some reduction
excellent reduction
1 log reduction
excellent reduction
Helminths excellent reduction
some reduction
excellent reduction
some reduction
excellent reduction
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Bacteria Typically, raw sewage contains 107 E. coli (MPN/100ml), the primary indicator for pathogens. The waste stabilisation ponds will reduce this number to a median of 1,000 E. coli (MPN/100ml), as reflected in current results for Blatherskite Park. Recent sampling at Blatherskite Park also detected nil Enterococci. DAF is unlikely to significantly reduce bacteria numbers other than those adsorbed to the algal biomass. The chlorination kill rate will be dependent on the reduction of turbidity in the water provided by the DAF unit. Studies conducted elsewhere have shown a significant 7 log reduction in SAT systems. Viruses Little work has been undertaken in the NT in this area. The recent pathogen sampling programme yielded a ‘nil Bacteriophages detected’ result at Blatherskite Park. Further treatment, particularly chlorination and SAT is expected to significantly reduce the presence of viruses in the final product water. Protozoa Protozoa generally settle out in waste stabilisation ponds and are not found in the final recycled water. In addition, Giardia is temperature sensitive and has a low ‘sludge’ survival age. Recent results from pathogen sampling in the NT showed a ‘no presence’ result for protozoa in three out of four WSP wastewater samples. Recycled water from Blatherskite Park detected Cryptosporidium at a concentration of 2 oocysts/10L (raw sewage contained approximately 1,200 oocysts/10L). DAF and chlorination will have little impact on Cryptosporidium although excellent removal is expected from filtration and SAT processes. Helminths Recent pathogen testing in the NT showed ‘no presence’ in WSP wastewater. However, it also showed ‘no presence’ in the raw sewage, therefore the results may not be reliable. Regardless, helminths are likely to be readily removed in the waste stabilisation ponds through sedimentation and retention processes. Excellent removal through both filtration and SAT is expected.
Heavy Metals Apart from potential pathogenic organisms, the only other potential health concern is from the excessive concentration of heavy metals and their potential accumulation in soil profile and crops. A full analysis of all heavy metals was undertaken and in no circumstances did the concentration of heavy metals exceed the SA Guideline values. Metals are not considered to be an issue as additional treatment will reduce these concentrations further. Identification of the minimum residence time of the infiltrate in the aquifer will only result from trials producing pathogen attenuation data, however, residence times of between three and 12 months can be anticipated in the final design based on experience elsewhere. Higher pre-treatment pathogen removal effectiveness, through measures such as DAF treatment or filtration, can also shorten these requirements. Human and environmental risks are extremely low with the current proposals.
Amount of Banked Water Proposed to be Used for Irrigation The irrigation demand for table grapes is estimated at 250 ML per 20 ha/yr, at full operation after five years. Water requirements for irrigated horticulture in Central Australia are commonly based on a maximum water requirement of 10 ML/ha/yr, with an assumption that all water will come from irrigation, although actual water requirements will vary considerable from year to year depending on rainfall and crop demand. While individual crops do vary in relation to period of maximum demand, there is a relatively modest difference in requirements between crops. The water being used for irrigation would all be supplied from the SAT scheme, although it may also be possible that some water, particularly in the early development phases may come from direct reuse of secondary-treated recycled water, prior to SAT, as is currently seen at Blatherskite Park.
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Some irrigation may also occur on pasture at the AZRI site. It is proposed that this would occur within the horticultural area as a measure to use excess water extracted in the absence of need from the horticultural venture. As such the volume required is unknown.
Application Methods of Recycled Water Sub-surface drip irrigation is proposed for horticultural crops, such as a major table grape development. Irrigation would be through sub-surface drip lines using low volume 2.3 L/hr emitters spaced every 0.5 m. This method of irrigation is very water efficient, maximizing water efficiency and also potentially allows for some flushing of materials through the soil profile. This is proposed for irrigation efficiency, salinity management and safety of reuse. Use of micro-irrigation and specifically drip irrigation which commonly provides a higher level of soil moisture within the root zone also adds to the tolerance of crops to slightly higher levels of TDS in irrigation waters. This phenomenon relies on the ease with which plants can extract pure water if there is low osmotic potential within the soil It is also proposed to develop some pasture irrigation at the AZRI site. It is intended to utilise a centre pivot irrigation system with low pressure, large droplet sprinkler heads that apply irrigation close to the ground (unlike the current irrigation system at Blatherskite Park). Time of day controls (preventing irrigation occurring outside the hours of, say 10 pm to 4 am) and weather controls (e.g. shut off the irrigation system if wind speed exceeds a predetermined limit) can be implemented to minimise off site impacts.
Proposed Crops to be Irrigated and Their End Use The current horticulture proposal is for the development of approximately 20 ha per year of table grapes over a period of five years. The potential for citrus and other climatically adapted crops will be considered and investigated in the future. Grapevines would be produced for the production of fresh table grapes and/or dried grapes. Citrus, melons and asparagus (if grown) would be for fresh consumption and citrus may be juiced. These are crops reasonably well adapted to slightly saline soil and water conditions and could be expected to grow well in the region and the crops have been produced locally in the past. Asparagus and melons are considered tolerant to moderately insensitive to saline conditions while grapevines and citrus are slightly more sensitive but still considered adaptable to slight salinity. There are also differences within individual crops, with varietal differences often quite considerable such that it is possible to select appropriate lines within each crop. However, it is expected that project management will also focus on minimizing the influence of longer term salinity issues through agronomic and irrigation management. There is an existing modest irrigated production of table grapes at Ti Tree north of Alice Springs and a new development east of Alice Springs also producing table grapes. Plants are known to exhibit a range of sensitivities to saline irrigation water. The proposed species for use in the horticultural programme are among the groups that are tolerant of the use of irrigation water in the 500 to 1,500 mg/L range, and additionally, varieties/rootstocks that are known to be superior in their tolerances to slightly saline water will be selected within the species.
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Furthermore, the project has generally, with the exception of melons, opted to use vegetatively propagated and perennial species. This adds to the tolerance of the crops as sensitivity is greater normally during the germination and establishment of the seedling phase in annual species.
Indicative Seasonal Activity for Horticulture Scheme Table 12 provides a summary of the seasonal work programme that could be expected, and the equipment likely to be used, for each of the crops that have the potential to be included in the horticultural scheme.
Table 12: Seasonal Horticulture Activity and Equipment Usage Month Grapevines Citrus Melons Asparagus January Post-harvest
nutrition and powdery mildew (high volume sprayer)
Harvest (by hand)
February March Bed-preparation
(Slash, bale, hoe, roll)
April Harvest (by hand)
May Harvest (by hand for fresh fruit, by machine for juice)
Harvest (by hand)
June Pruning (by hand and by machine saw)
Harvest (by hand)
July Pruning (by hand) Dormex application to initiate bud break
August Weed control (low volume application of glyphosate)
September Shoot thinning (by hand) Early season powdery mildew control (high volume sprayer)
Control of aphid/scale (release of parasitic control agents)
Plant (machine planter)
Weed control (low volume application of glyphosate)
October Gibberellic acid applications to regulate growth (high volume sprayer) Bunch thinning/trimming
Control of powdery mildew (high volume sprayer) Weed control (low volume application of
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Month Grapevines Citrus Melons Asparagus (by hand) glyphosate)
November Botrytis control (high volume sprayer) Application of ethylene as berries mature to promote berry colour development Grape harvest (by hand)
Harvest (by hand)
December Application of ethylene as berries mature to promote berry colour development Grape harvest (by hand)
Gibberellic acid sizing (high volume sprayer)
Harvest (by hand)
Use of Agrochemicals The agronomic inputs for the project include a range of inorganic fertilizers – phosphorus, nitrogen, calcium, magnesium, sulfur, potassium plus use of a modest range of common herbicide, fungicide and plant protection products. Fruit fly monitoring and control is planned through pheromone traps. The agronomic inputs and practices are those commonly used in modern horticultural production for this range of crops. Herbicides are chemical products that have the primary purpose of killing or inhibiting the growth of plants by defoliation, affecting plant metabolism, preventing leaf or root growth or stopping the movement of nutrients within the plant. Knockdown herbicides are those herbicides which act in a short period of time to kill or inhibit the growth of plants but do not have residual control properties. Residual herbicides are those herbicides which remain in the plant or soil and act over a period of time to kill or inhibit the growth of plants. The herbicides proposed for use in the horticultural scheme are knockdown herbicides and do not have residual effects on soils or plants.
The herbicides and other methods of pest control proposed to be used include: • Glyphosate herbicide for weed control; • Pheromone traps for fruit fly control; • Sulfur for mite and powdery mildew
control; • Bio-control agents for aphid and scale
control; • Copper for fungal control; and • Scala/Rovral for botrytis control. The fertilizers and soil conditioners proposed to be used include: • Urea for nitrogen; • Potassium nitrate for potassium; • Mono-ammonium phosphate for
phosphorus; • Magnesium sulfate for magnesium; • Calcium nitrate for calcium; • Zinc sulfate for zinc; • Humic acid as a soil conditioner; • Molasses for carbon; and
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• Trace elements. Other agrochemicals that may be used as required on grapes include dormancy breaking chemicals, such as: • Dormex (Hydrogen cyanamide); • Gibberellin for growth regulation and
reducing vegetative growth (also known as Gibberellic acid); and
• Ethylene products for fruit maturation and control of ripening (also known as Ethrel and Ethephon).
The range of agrochemicals available and recommended within the horticulture industry change over time and new products are constantly being developed to improve environmental management. Therefore, it is not possible to list all those agrochemicals that may be used within the
horticultural project, but it is generally illegal to use agrochemicals other than recommended on product labels. It is expected that the horticulturalist would adhere to these requirements. A rising trend in horticultural production is to use integrated pest management or biological control agents where appropriate and this is also planned for this project, for control of aphids and scale insects. All of the proposed products for use in the horticultural scheme are registered for use in grape production and widely used in Australia, including in the Ti-Tree area north of Alice Springs. There have been no reported issues or problems with use of the products in the 15 or so years grapes have been grown north of Alice Springs.
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JUSTIFICATION FOR THE PROPOSAL The Alice Springs Water Reuse Scheme will deliver clear triple bottom line benefits for the Alice Springs Region. These include environmental and health improvements and opportunities for developments using recycled water. This scheme represents the preferred solution to the various issues associated with the present operation of the WSP.
Need
Environmental Concerns Wastewater is currently discharged from the WSP to the nearby Ilparpa Swamp. The nutrient-rich water contributes to the growth of non-native grasses and invasive reeds in the swamp. The introduced reed Typha domingensis (Cumbunji) is now the dominant species within Ilparpa Swamp, whereas previously it was virtually unknown in the area (Arid Lands Environment Centre, 2000). Similarly, native species such as Coolibah, which rely on periodic flooding (rather than permanent inundation), are in decline. Excessive algal growth has been observed in Ilparpa Swamp and is considered to be a direct result of the nutrient-rich wastewater inflow. Under a natural system, Ilparpa Swamp would only hold water during rainfall events, allowing native plants to be re-established. Ilparpa and the Commonage are important areas within the Alice Springs community for recreation, bird watching, tourism and cultural aspects. Ilparpa is botanically rich with numerous plant taxa considered to be of national and regional conservation significance (Arid Lands Environment Centre, 2000). Cessation of wastewater overflow into Ilparpa Swamp will allow rehabilitation of the natural environment, to further enhance its value to the community.
Mosquitoes The increase in reed growth at Ilparpa Swamp reduces wave action resulting from wind, providing ideal conditions for mosquito breeding. There are approximately 15 species of mosquito within the Alice Springs area, and several of these have been shown to be vectors for Ross River Virus and Murray Valley Encephalitis. Ross River Virus can cause debilitating symptoms which may persist for several years and Murray Valley Encephalitis, in a small percentage of cases, can cause death or permanent brain damage in survivors; mosquitoes present a serious health issue for surrounding residents, users of nearby recreational facilities and workers. The issue of mosquitoes at Ilparpa Swamp has been a long standing one. The proposed water reuse scheme will result in the cessation of dry weather overflows into Ilparpa Swamp, as of the 31st December 2005. This will significantly reduce the availability of standing water for mosquito breeding.
Community Desire for Conservation of Water In August 2000, the Alice Springs Urban Water Management Strategy Workshop was held. A discussion point for the workshop was appropriate use of the precious resource of water and potential reuse within the arid landscape of Alice Springs. The proposal to store water in groundwater aquifers will significantly reduce the amount of water currently lost to evaporation and increase the range of potential uses of the water because of its higher quality than that currently being discharged to Ilparpa Swamp or used in direct irrigation at Blatherskite Park.
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Community Preference for Recycled Water A survey of 539 Alice Springs residents identified that there is a significant concern about conservation of water and that water reuse is preferred to continued evaporation and discharge. It was also considered that expansion of the WTP and WSP were not viable options, as they would require significantly larger areas of land and had the potential to exacerbate existing odour and recycled water infiltration issues in the area. It would also not address the issue of dry weather overflows into Ilparpa Swamp or loss of water through evaporation.
Regional Industry Development The existing groundwater quality is such that it is too saline for most horticultural crops to grow successfully, the most notable exception being dates. This, in conjunction with the desire to restrict potable water for non-irrigation purposes, has limited growth of the horticultural industry in the region. The current proposal provides an opportunity to develop and grow a horticultural industry to provide fresh produce for both local and, possibly, interstate markets.
Choice of Water Treatment Scheme Other recharge methods were considered, such as bore injection and continuous pond infiltration, but SAT was selected because of its superior capability to improve water quality. SKM (2000a) investigated options for recycled water use and increasing the amount of water available for town supply. The suitability of five different schemes was assessed, only two of which involved recycled water. The schemes involving use of recycled water proposed tertiary treatment through micro-filtration and desalinisation (to enable reuse in the town water supply). However, the infrastructure costs associated with these were very high.
The use of a DAF plant and chlorination was subsequently investigated (Varidel, 2003) and recommended as the preferred option for wastewater treatment for irrigation purposes. The types of irrigation proposed, while an improvement on current systems, are not as effective in reducing soil salinity issues as the methods proposed for the horticultural scheme (i.e. sub-surface drippers). However, the use of sub-surface drippers requires a higher quality of water than would be provided by DAF and chlorination alone, as drippers tend to clog quickly if the amount of particulates in the water is high. SAT provides a polishing effect to the DAF treated recycled water. This process further removes particulates to allow use of the extracted water in a dripper irrigation system, which was the preferred method to mitigate against soil salinity impacts. Comparison with water reuse schemes elsewhere (refer to Appendix 2) has shown that a range of options are available for wastewater treatment and use of recycled water. These options include construction of infiltration basins or use of naturally occurring wetlands for the purpose of SAT. In the proposed programme, the use of wetlands, such as Ilparpa Swamp, was not feasible because of the environmental issues this has created in the past. A trial was previously conducted at the WSP to test the level of filtration of particulates from wastewater through a gravel bed. This method was proven to be effective, but a large area would be required to provide sufficient recycled water for use in horticulture. Analogous to this approach is SAT, where the natural geological structures below the infiltration basin act as a gravel filter.
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Alternative Sites A number of sites were considered for the establishment of the SAT and horticultural schemes and four were considered at a detailed level. Table 13 provides an
assessment of each of these sites and the environmental, social and economic aspects of each.
Table 13: Comparison of Possible Water Reuse Sites. Site Environment Social Economic AZRI • Best soils and
geology for SAT and recovery
• Good horticultural soils
• Designated as a research facility for the development of business and industries to support growth in the NT
• No land title issues • Maximises future
opportunities to use recycled water in a variety of locations
• Easy access for people working on the site
• Close proximity to local residents requires detailed planning and control on the site
• Closest site to the WSP, minimising expenses in supplying wastewater
• Most utilities already available
• Associates the positives aspects of industry and jobs creation for Alice close to town and government
Alice Springs Airport • Soils and geology not as good for SAT and recovery
• Possible losses of recharged water to other aquifers
• Good horticultural soils
• No land title issues • Provides future
opportunities to use recycled water in a variety of locations
• Easy access for people working on the site
• Further away from WSP so more expensive to supply wastewater
• May require land rental and would be more expensive than current
Owen Springs • Few opportunities for SAT or water recovery
• Land title issues would make it unlikely that the December 2005 deadline for ceasing dry weather overflows into Ilparpa would be met
• Significantly further away from WSP so much more expensive to supply wastewater
Brewer Estate • No recovery opportunities
• Poor soils for horticulture
• Further for people to travel to work
• Extremely expensive to supply wastewater from WSP
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Site Environment Social Economic • Potential conflict
between noxious industries and food crops
The Arid Zone Research Institute was selected as the preferred site for the project because: • The purpose of AZRI is for research
and knowledge development, which has synergies with the proposed programme;
• AZRI already has horticultural expertise to support the scheme;
• Infrastructure, such as power, water and sewage, is already in place;
• Government ownership provides the flexibility to effectively manage recycled water use; and
• AZRI has established links with similar initiatives, such as: o The Desert Knowledge Precinct; o The Bush Foods Industry; and o The Camel Industry.
Subsequent site investigations have shown that the AZRI site has the appropriate soil types and hydrogeology for the development of a SAT scheme.
Cost Benefit Analysis Many of the benefits of the proposal are non-financial in nature (e.g. cessation of dry weather overflows to the Ilparpa Swamp, reduction in water loss through evaporation, mosquito habitat reduction). Nonetheless, these benefits are substantial. Varidel (2003) made a series of recommendations about improving the quality of recycled water currently being used for irrigation purposes, as it did not meet guidelines for recycled water use in areas with unrestricted public access. Use of the existing wastewater treatment infrastructure, with addition of treatment measures and underground storage, was considerably more cost effective than implementing a whole new treatment system, expansion of existing treatment ponds or installation of aboveground storage tanks (SKM, 2000a; Varidel, 2003). It is estimated that the installation of the DAF plant and chlorination system will cost $2.3 million in capital works. A comparison of the costs for different uses of recycled water and different methods of application (i.e. different irrigation methods) is provided in Table 14.
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Table 14: Comparison of Costs and Benefits. Options Costs Benefits Build another storage pond • Estimated $600,000 capital
cost • Continued evaporation of
water • Extra 50 ha of evaporation
ponds is required
• 40 % reduction in overflows to Ilparpa Swamp
• Relatively cheap and can be implemented straight away
• No upgrade of existing treatment system required
• Short term development timeframe
Extend existing tree farm by about 10 ha and increase amount of irrigation
• Estimated $800,000 capital cost
• Disposal of valuable resource
• Irrigation demand is low in winter, when effluent overflows occur
• Ongoing issues of soil salinity and groundwater because of irrigation practices
• 20 % reduction in overflows to Ilparpa Swamp
• Relatively cheap • Could provide benefits such
as production of firewood, mulch or exotic timbers
• No upgraded of existing treatment system required
• Short to medium term development timeframe (approx. 5 years for trees to mature)
Reduce water usage in the home • Estimated $1.8 million
capital cost • Takes about 5 years for
savings on water bills to pay for investment in water saving devices
• Sewage inflows would have to be reduced by about 40% to eliminate effluent overflows into Ilparpa Swamp and this would be difficult to achieve through water use reduction alone
• Reduce sewage inflows by using water efficient showers, toilets and basins and by adjusting evaporative air conditioners
• 40 % reduction in overflows to Ilparpa Swamp
• Reduces water bills for customers
• Delays need to upgrade existing sewage system
• Reduces sewage treatment costs
• Reduces strain on drinking water supplies
• Short term development timeframe (but ongoing)
Reduce groundwater and rainwater infiltration • Estimated $2.9 million
capital cost • Relatively expensive • Estimated to reduce
• Reduce sewage inflows by lining sewer mains
• 33 % reduction in overflows to Ilparpa Swamp
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Options Costs Benefits sewage inflows by only 10%
• Current groundwater inflows assist in removing salt from Town Basin
• Reduces sewage treatment costs
• Sewer mains will last longer and operate better
• Likely to reduce effluent salinity
• Short to medium term development timeframe
Develop irrigation of parks, garden and horticulture • Irrigation of areas with
unrestricted public access requires a higher level of treatment than for plantations
• Relatively expensive • Additional or alternative
sewage treatment required • Additional storage and
separate pumping and reticulation system is required
• Need to ensure that demand for effluent exists and will continue to exist in future
• Cheaper irrigation water for these applications
• Less strain on town water supply, provided effluent is substituted for existing supplies
• Medium to long term development timeframe (greater than 5 years to establish)
Inject highly treated water into groundwater system • Relatively expensive
• Lack of support in the general public
• Higher risks (but these can be managed)
• Can use existing water supply aquifers for storage over winter
• Recharges a non-renewable resource
• Makes use of existing water supply infrastructure
• Medium to long term development timeframe (greater than 5 years to establish)
SAT and recovery • Community concerns about location of horticulture and soil salinity
• Requires infrastructure development
Infrastructure Development approx. $6.2 million: • DAF plant and chlorination
system approx. $2.3 million
• No need to increase the area for effluent treatment at WTP
• SAT provides high level treatment (superior to direct injection)
• Environmental benefits to Ilparpa Swamp through cessation of dry weather overflows
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Options Costs Benefits • Pipeline from WSP to AZRI • Infiltration basins and
monitoring equipment • Extraction wells and pumps Horticulture infrastructure costs yet to be determined: • Building infrastructure • Pipes and irrigation systems • Extracted water holding
area • Ongoing operational costs Ongoing environmental and water quality monitoring costs yet to be determined: • Building infrastructure • Irrigation infrastructure • Crop infrastructure Rehabilitation of Ilparpa Swamp: • Power and Water will
provide $220,000 over next three years to assist in rehabilitating the area
• High level of wastewater treatment, to maximise water quality and minimise human health impacts
• Reduces loss of water through evaporation, thereby also decreasing soil salinisation issues at the WTP site
• Allows improvement in irrigation design to minimise environmental impacts
• Provides opportunity for regional development of horticulture
• Provides opportunity to investigate other potential users of recycled water
• Provides increased employment opportunities
• Provides fresh produce for local markets
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PUBLIC CONSULTATION Community consultation has been ongoing since 2000, when the Alice Springs Urban Water Management Strategy was first developed. Since that time, consultations have focussed on general water issues in Alice Springs, including long-term strategies for water use, education of community on wise water use and use of recycled water. A formal Community Consultation Strategy was developed in 2003, which outlined the key stakeholders, key messages, effective methods of communication and methods for evaluating consultation effectiveness. The consultations have taken the form of: • Interviews on local radio; • Advertisements and press releases in
local printed media; • Information fliers and posters placed at
key locations around Alice Springs, including local shopping centres and the reception areas of government agencies;
• Workshops to provide advice and guidance on the Alice Springs Urban Water Management Strategy;
• Open days at the WTP and AZRI to demonstrate the research that has been undertaken;
• Stakeholder newsletters; • Letters to residents near to the AZRI
site; • Articles on the DIPE and Power and
Water websites; • Attendance at local community group
meetings, such as the Alice Springs Rangelands Ecology and Biology Technical Group and the Rural Areas Association;
• Responses to written and verbal enquiries from stakeholders and residents; and
• Public meetings to present aspects of this PER.
A table summarising of these consultations from August 2000 to the present are provided in Appendix 3. The major outcomes from these consultations are as follows: • Awareness of the Alice Springs Urban
Water Management Strategy; • Awareness of the Alice Springs Water
Reuse Scheme and associated research undertaken;
• Identification of areas of concern to residents and other stakeholders (which have been incorporated into this PER);
• Increased understanding of how the proposed SAT scheme works;
• Opportunity for members of the public to voice concerns;
• Increased awareness of water issues in Alice Springs;
• Identification of issues associated with ceasing dry weather overflows to Ilparpa Swamp, such as change to the habitat available (outside of the scope of this PER);
• Identification of concerns about the change in water availability in the existing evaporation ponds and the effect of this on migratory birds (outside of the scope of this PER);
• Identification of significant cultural sites and items within the AZRI boundary;
• Opportunity for potential future users of recycled water to identify their interest; and
• Opportunity for current concerns about aspects of horticultural operations to be addressed (which have been incorporated into this PER).
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SOIL DISTURBANCE AND SALINITY Existing Environment
Land Unit and Land Capability The proposed SAT and horticultural schemes will occur in the vicinity of several land units with the variable landform, slope,
capability, and erosion risk (DIPE, 2001). These are illustrated in Table 15.
Table 15: Land Capability Characteristics. Land Unit Landform Description Slope Capability Class for
SAT Basins and Horticulture
Development Erosion Risk
4.05 Remnant Flood Deposit Flats with Corkwood over Buffel Grass.
1% Very Good High
4.09 Broad Alluvial Flats with Ironwood and Corkwood trees over Buffel Grass and native grasses.
1% Very Good Severe
5.05 Elevated Sandy Floodplain Bars with Ironwood and Witchetty Bush over annual and perennial grasses.
3% Very Good Moderate
5.09 Remnant Drainage Channels with Coolibah over Buffel Grass.
1% Very Good Severe
5.13 Remnant Loamy Sand Deposits with Witchetty Bush over Buffel Grass.
2% Very Good High
5.14 Prior Floodout Distributary Channels with Ironwood, Corkwood over Buffel Grass.
1% Very Good High
(Source: DIPE, 2001) The site of works will predominantly occur on land units 4.05 (Remnant Flood Deposit Flats) and 4.09 (Broad Alluvial Flats) (Figure 11). Remnant Flood Deposit Flats are not expected to flood frequently because of landform slope and direction and are a
relatively stable landform. Characteristics of this land unit are provided in Table 16. Broad Alluvial Flats may be eroded by sheet flow, over-bank stream flow, wind and surface disturbance. Characteristics of this land unit are provided in Table 17.
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Figure 11: Land Units of the Project Area
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Table 16: Characteristics of Remnant Flood Deposit Flats Attributes Development Risks Capability Class
Slope (%) 1 Erosion High Formed Roads
Very good
Relief (m) 3 Rock Fall None Shallow Excavations
Very good
Soil Depth (m) > 2.0 Sheet Flooding
High Septic Disposal
Very good
Surface Condition
Loose Inundation High Horticulture Very good
Depth to Substrate (m)
> 2.0 Salinity None Building Foundations
Good
pH 6.5 to 9.0 Alkalinity High (at depth) Landscaping Very good Runoff Slow Acidity None Permeabililty High Drainage Well drained Salinity (ms/cm)
23.1 to 59.0
(Source: DIPE, 2001) Table 17: Characteristics of Broad Alluvial Flats
Attributes Development Risks Capability Class Slope (%) 1 Erosion Severe Formed
Roads Good
Relief (m) 1 Rock Fall None Shallow Excavations
Very good
Soil Depth (m) > 2.0 Sheet Flooding
Severe Septic Disposal
Very good
Surface Condition
Loose with some surface
matting Inundation High Horticulture Very good
Depth to Substrate (m)
> 2.0 Salinity None Building Foundations
Good
pH 6.0 to 9.0 Alkalinity High (mid-profile) Landscaping Very good Runoff Slow Acidity None Permeabililty Moderate Drainage Moderately
well drained
Salinity (ms/cm)
30.7 to 87.4
(Source: DIPE, 2001)
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Detailed Investigations Previous studies have shown that the soils across the broadly defined site are variable, both laterally across the area in terms of surface characteristics and down the profile. A number of sites examined have heavier clay or clay loam bedded layers in the profile, but there are a range of soils that are generally in the broad textural classes required for soil infiltration basins. Varidel (2003) broadly classified the soils as coarse surface textured red earths. The Australian Soil Classification identifies them as Red Kandosols (Isbell 1996). This is also consistent with previous sampling by Emerson and Weissman (1997). The soils are neutral to alkaline at the surface with neutral to alkaline subsoils. This is also verified by the recent chemical analyses and data from pits by Lennartz (2005). The soils of AZRI contain less clay than the existing irrigation sites on the Commonage, and tend to be in the main, sands and sandy loams at the surface. This implies that salinity build up will be less of a problem at the AZRI site because the leaching fraction can be higher. Selection of project areas at the AZRI site for detailed evaluation avoided the naturally saline soils often found in the depressions adjacent to the Todd River levee banks to the east, where numerous soils in the area have salt levels capable of limiting plant growth. The well drained soil types, such as red earths, are capable of flushing salts down the profile with irrigation (Wright, 1959). The areas originally selected have been refined through a number of stages. The overall thrust of the numerous previous assessments indicates that there are no physical or chemical barriers to plant root penetration at the AZRI site. While recent data (Lennartz, 2005) indicates the presence of narrow bands of heavier soils (sandy clay loams, clay loams) deeper in the profile these are unlikely to be a major impediment to internal drainage to significant depths.
The majority of AZRI soils, are non sodic (Exchangeable Sodium Percentage < 6), contain little salt, and the combination of these physical properties make the soils suitable for infiltration for a soil aquifer treatment system and irrigation, with the irrigation water expected to be slightly saline and slightly sodic. Selection of the areas for the infiltration basins and the horticultural project fit this category. The phosphorus absorption curves for these soils also indicate an ability of the soils to adsorb substantial amounts of phosphorus, a common issue in both recycled water infiltration and agricultural production. The recycled water for disposal has a slightly alkaline pH, medium-high salinity and medium sodium adsorption ratio (SAR). However, this data is known to vary during the year with lower salinity and lower SAR values more common during the high flow periods of the winter/spring months. The sustainable use of such recycled water for irrigation requires the maintenance of suitable chemistry and permeability within the soil. Generally it can be reasonably expected that such water will increase the surface pH of soil, as there is relatively modest soil buffering capacity, at least while organic matter is low. Studies at broadly similar sites where recycled water has been used for irrigation (primarily over spring and summer) provide some indicators of longer term issues at the proposed project site on AZRI. Lennartz (2005) undertook a study on soils within the area with the primary objective to establish baseline soil properties and to evaluate the basic geotechnical features, to determine which areas may be suitable for storage, infiltration and recovery of recycled water. Stage 1 of the investigation was to enable the identification of at least five suitable sites with Stage 2 investigations concentrating detailed work on two selected sites. Specific tasks included:
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• Characterizing the occurrence, nature and variability of the near surface soil profile;
• Interpreting soil profiles to identify and define areas the show suitable and comparable characteristics that can be targeted for further detailed survey;
• Determine the basic engineering properties of each soil type and composite profiles; and
• Establish the presence and distribution of any potential problem soils in the area and potential issues that may arise with changed land use.
A total of 29 trenches were excavated and logged, commonly to between 1.5 and 2.4 m below soil surface. Soils with up to 30 to 35 % clay content in the profile were identified. However, the impact of these soils (often quite narrow bands of about 10 cm) on infiltration rates is yet to be determined at a field scale. Basic soil parameters were tested and included horizon depth, texture, pH and coarse fragment description. Line cross-sections indicated an extreme variability between individual trenches making a cross-sectional interpretation unreliable. The broadly spaced trenches do however, provide a basis from which further detailed work can be continued and from which infiltration sites can be selected.
Samples from individual profile horizons and from alternate trenches were collected and were tested for salinity. Permeability testing of individual lithologies was also conducted. Following the individual regional trenching programme and the unpredictability of lithologies between profiles, a costeaning programme was proposed. It was initially proposed to costean (trench) a 270 m transect covering the interpreted palaeochannel that trends north west to south east through the existing DBIRD horticulture block. The advantage of a continuous deep costean is that a lateral interpretation of the sub-surface soil profile can be made. Undulations and lenses of soil and sand could be measured exactly and further interpretations and scientifically based testing and interpretations can be made with excellent base line information. A full costean over the 270 m became impractical due to the hardness of the ground and the time allocated to the exercise, so a range of short costeans at 10 m to 20 m intervals was used. Physical textural properties of the soil were observed and not directly tested due to the inaccessibility of costeans and depth of excavation. An interpretation made from the information gained from the costeaning has been compiled (Lennartz, 2005). A sample of an excavation is shown in Plate 1.
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Trench 2 Surface Description: Loose. 2% 2 mm and 1% 4 mm angular quartz fragments. Soft. 0.00 m – 0.15 m: Loamy sand (LS). Single grained with a sandy fabric. 2% 2 mm and 1% 4 mm angular quartz fragments. Non calcareous. Field pH 6.5. 0.15 m – 0.50 m: Sand loam (SL). Single grained with a sandy fabric. 2% 2 mm angular quartz grains. Field pH 7.0. 0.50 m – 0.65 m: Heavy loamy sand (LS(H)). Single grained with a sandy fabric. 2% 2 mm angular quartz fragments. Field pH 8.0. 0.65 m – 1.0 m: Loamy sand (LS). Single grained with a sandy fabric. 2% 2 mm angular quartz fragments. Field pH 8.5. 1.0 m – 1.30 m: Sandy clay loam (SCL). Single grained with a sandy fabric. 2% 2 mm angular quartz fragments. Field pH 8.5. 1.3 0m – 2.00 m: Sandy loam (SL). Single grained with a sandy fabric. 3% 2 mm angular quartz fragments. Field pH 9.0 2.00 m – 2.40 m: Sandy loam (SL). Single grained with a sandy fabric. 5% 2 mm and 3% 4 mm angular quartz fragments. Field pH 9.5.
Plate 1: Example of Excavation Undertaken in Costean Programme The cross-section clearly shows the interlayering of various alluvial flooding events and, as observed in this and other trenches, the ‘text book’ examples of graded bedding. Graded bedding, the grading from basal coarse, sand sediment to overlying fine, clay sediment, is evidence of large scale flood inundation events that have combined to form the present day soil profile. It is expected that the combination of all soil profile datasets in conjunction with later stage permeability and particle analysis work will enable the identification of suitable infiltration sites within the nominated area at AZRI.
In summary, the majority of the trenches show surface soils (0 to 2.4 m) that are in the broad soils groups of lighter sandy loams, loams and similar groups with a few areas having surface soils in the clay loam and sandy clay loam and similar ‘heavier’ textural classes. Organic matter levels in these soils appear low. This work was to allow further definition of the areas with the lighter surface soils to allow selection of the areas for more detailed studies, as the lateral complexity of the soil texture and structures in the area is high.
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Soils Suitable for SAT Basins The preferred surface soils for SAT systems are sandy loams and loamy or fine sands, based on US studies (US EPA, 2004), with the depth and interleaving of heavier soils expected to have some influence on permeability. There does appear to be a range of these soils within the proposed site, which will be broadly suitable for the proposed use. However, as indicated earlier some narrow layers of slightly heavier soil materials is often inter layered with lighter textured soil materials within the profiles as characteristic of the overall site structure, along with lateral complexity and field studies at the medium scale are necessary to fully determine the infiltration capacities. As infiltration basins are quite large with four sub-basins within each one of them, a range of soil structures are likely beneath any one basin, given the complex variability and structure of the soils over short distances. A variable infiltration rate may be common within any one basin as well as between basins due to this soil variability.
Soils Suitable for Horticulture Chemical analyses of the soils in the proposed areas are broadly indicative of the local soils. Phosphorus is modest, surface pH is generally close to neutral pH 7 with a slight variation of about 0.5 unit around neutral and tending to rise slightly with depth, iron levels tend downwards with depth and are modest values. It is interesting to note that soil pH data from the soil survey work tends to show higher pH with depth than in this cross section of results. The calcium / magnesium ratios are around four, which is lower than desirable for horticultural soils, but not unusual and may be adjusted with calcium applications. Cation exchange capacity (CEC) is fair to good, with sodium a very small proportion of the total CEC. The broad parameters of the horticultural soils are light textured loams, loamy sands and some interspersion of slightly heavier
textured surface soils such as sandy clay loams and clay loams. There is no steady pattern of textural changes with depth, a common pattern in many soils, but the interspersing of alternate lighter and heavier textured soil bands between the surface and around 2 m below ground which reflects the pattern of an intergraded depositional area. While some hard surface soils are apparent within the proposed areas, the soils appear broadly suitable for use to grow the nominated crops. Careful design and operation of the irrigation system will be needed to provide good soil and water management. However, the use of recycled water in horticulture and agriculture is very common and can commonly include conventional production systems as well as recreational areas, e.g. turf and lawns.
Potential Impacts
Increase in Soil Salinity and Sodicity Sodic soils contain a significant proportion of sodium associated with clay particles. AZRI soils are not sodic, but soils can be modified due to sodium in the irrigation water. As the amount of sodium adsorbed to clay particles increases, the physical and chemical properties of the soil change: • Soil becomes more prone to
dispersion and erosion; • Coarser structure; • Higher density; and • Lower hydraulic conductivity. In Australia, sodicity is usually classified by the following levels, although these levels may be modified slightly depending on the mineralogy of the clay in the soil: • Exchangeable Sodium Percentage < 6
- non-sodic; • Exchangeable Sodium Percentage 6 -
14 – sodic; and
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• Exchangeable Sodium Percentage >15 - strongly sodic.
While changes in soil salt concentration due to irrigation water application often occur over a relatively short period of time (a few months), changes in Exchangeable
Sodium Percentage (ESP) may occur over a period of years due to the relatively slow rate of replacement of exchangeable cations by sodium. The following diagram from earlier work by Varidel (2003) provides an example of this issue for the AZRI soils.
Figure 12: Salinity and Sodicity of Soils (Source: Varidel, 2003) Ideally, the soils receiving the recycled irrigation water should be in the ‘flocculated’ zone to ensure that the soil structure remains open and free-draining. Soils in the ‘spontaneously dispersive’ zone tend to have very poor structure, giving rise to poor permeability, poor root penetration and therefore poor crop health. The ‘mechanically dispersive’ zone is an at-risk area in which the soils have a strong tendency to disperse under some circumstances such as when spray irrigated or if cultivated while moist (Varidel, 2003). A range of studies indicate that the soils at the AZRI site are generally in the mechanically dispersive category, based on assumed values for the Sodium Adsorption Ration (SAR) and electrical conductivity (EC), and as such require careful management to ensure long term productive use for horticulture. Mechanically dispersive soils have a strong tendency to disperse under certain
conditions, such as spray irrigation or cultivation while moist. However, some previous work, which directly examined the current wastewater quality, indicated that it tended to be of a ‘safe to apply to soil’ quality, using a SAR for the recycled water of 3.2. Other data used in previous work by Varidel (2003) used SAR values of 9 for wastewater, but data on the period of year when these values were obtained is not stated. This tends to indicate quite wide fluctuations in wastewater quality. There is a need to differentiate between the SAR of the receiving soils and the SAR of the irrigation water in understanding the issues involved. Wastewater quality and volume does vary through the year, with mid to late winter and spring having maximum sewage flows and better wastewater quality in most years, based on accumulated Power and Water data. Thus, an opportunity exists to select periods for infiltration when the wastewater
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quality is relatively more suitable, while having larger volumes that can be sent for disposal to the proposed SAT scheme at the AZRI site. This should enable a degree of management influence on the quality of the infiltrate moving to groundwater and potentially on the quality of the extracted water for reuse. Irrigation with recycled water (assumed salinity at around 1,000 mg/L TDS) is expected to raise the salinity of the soil water between rainfall events, but these rainfall events will help prevent dispersion from occurring and keep the soil structure open. The use of gypsum in the irrigation water, or applied to the wetted zone of the soil, also assists in maintaining soil stability. Data obtained from current recycled water disposal sites at Blatherskite Park and the tree lot indicates that poorly managed irrigation with recycled water over the past twenty years has significantly increased the soil ESP. Given that the soils at the AZRI site are broadly similar to those at the existing recycled water irrigation/disposal sites, it is reasonable to conclude that the long-term impacts of recycled water irrigation will be similar at both sites, unless efforts are implemented to modify the processes that occur in soil, improve the quality of the recycled water used for infiltration or irrigation on the proposed AZRI sites and improve methods of delivery of this recycled water. The use of a SAT scheme and appropriate irrigation techniques will significantly reduce the risk of long term impacts on soils at the AZRI site. Gypsum is the usual product used to manage sodicity in cultivated and managed agricultural and horticultural areas irrigated with less than ideal quality water with sandy loam surfaces, as this will prevent densification caused by dispersion and crusting. Previously, gypsum was applied as a fine solid, but it is now common to use micronised dispersed material as a liquid, often applied with the irrigation water. Gypsum should be part of the management strategies for long term soil stability required by the horticultural project as well as the SAT soil receiving basins.
Concerns with salinity relate to possible impacts to the soil’s osmotic potential, specific ion toxicity within the applied water (commonly sodium, chloride and boron), and degradation of soil physical conditions. These conditions may result in reduced plant growth rates, reduced yields, and in severe cases, total crop failure. In the long term without appropriate practices in relation to soil and water management the area could be rendered unfit for economic horticultural production due to increasing salinisation.
Soil Compaction and Erosion The light soils of the entire AZRI site are prone to compaction, due to the low clay percentages and poor structure. The soil particle size analysis from Emerson and Weissman (1997) indicate that compaction through inappropriate cultivation and traffic, or chemical dispersion could easily occur and result in the formation of very dense material. The hydraulic conductivities of these soils initially is typically high, because the light textures have significant pore space and high hydraulic conductivities allow salts to be readily leached below the root zone. Some modification to these generalities is expected due to narrow, denser soil layers (clay loams and sandy clays) at various depths within the profile (Lennartz 2005), but the comment is generally valid. This high hydraulic conductivity is an advantage in soils used for recycled water irrigation. The quality of the water extracted from the SAT scheme is potentially likely to be ranked as medium to poor at a nominal inferred value of 1,000 mg/L TDS, so maintenance of uncompacted soils is very important to ensure continued high infiltration levels. The proposed sites for the SAT basins and the horticultural venture are situated on Land Units considered to have very good capability for shallow excavations and horticulture, but high (Land Unit 4.05) and severe (4.09) erosion risks for development.
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Nutrients Varidel (2003) examined the nutrient balance for irrigated horticultural and pasture areas at AZRI using wastewater as a source of recycled water. Phosphorus is readily bound into the soil structure and is only released when the phosphorus concentration in the soil water falls below an equilibrium threshold. This means that many soils have the capacity to adsorp phosphorus for an extended period of up to several decades before becoming saturated. Once the soil’s phosphorus sorption capacity is exhausted, excess nutrient will leach to groundwater. Clay soils have a higher capacity to adsorp phosphorus than sandy soils, so the soils at the AZRI site will have a relatively low phosphorus-sorption capacity. While this scenario is different to the system proposed, as tertiary treated recycled water will be directed to the soil via infiltration basins, the same principle potentially applies to the infiltration basin soils. Varidel (2003) found that the physical capability of the soils at AZRI to adsorb phosphorus was approximately 740 kg/ha, if recycled water from the WSP was used directly for horticultural irrigation, without treatment to remove phosphorus. In the current programme, a significant amount of phosphorus will be removed through DAF treatment and during the SAT process and the proposed application method for horticultural irrigation will significantly reduce the likelihood of soil phosphorus saturation occurring at AZRI. Irrigation for pasture development will use low impact spray systems, thereby minimising application rates. However, some caution in relation to nutrient loading is advised in the infiltration basins. Some phosphorus will be sorbed to soil during the infiltration phase of the SAT project. If it were assumed that tertiary treatment removed only a minimal amount of nutrient, it is more likely that phosphorus sorption could reach saturation quite quickly in the infiltration basins.
The issue of excess nutrients does require management, both for the infiltration basins and in the horticultural project, assuming some phosphorus is still present in the extracted irrigation water. In the longer term if phosphorus is not removed, then this would move to the groundwater, after the soil is saturated for phosphorus. At lower excess application rates for both phosphorus and nitrogen, if these nutrients were removed prior to infiltration, it is estimated that it would be 75 to 100 years before the soil phosphorus capacity was reached, assuming no prior intervention at the soil or crop management phase. Intervention at the horticultural site, such as the augmenting of soils with organic material will assist in increasing soil sorption capacity.
Safeguards
Irrigation Management and its Influence on Soil Parameters In broad terms, independent of which type of irrigation system is used, the irrigation system needs to be managed so that the movement of excess water to the groundwater is minimised, but still provides sufficient flow to flush salts through the root zone and prevent accumulation in the surface soils. One method of achieving this is to use a ‘pulse’ scheduling system. This involves an irrigation cycle under which only enough water to meet crop requirements is applied most of the time, with an occasional heavy application of water to provide the flushing flow. This technique is especially successful with sprinkler irrigation used with broad acre crops or pastures and has been successful in other locations (including in Israel under comparable climatic conditions and soils). Options to use a range of newer design low pressure sprinklers in a range of various operating systems, also reduce evaporative losses and deliver water more efficiently and are a superior option.
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Ensuring sufficient water is applied to leach salts from the root zone will require specific on site monitoring and management. Electrical Conductivity (EC) profiles should be measured in soil using a field probe at least monthly for the first twelve months to ensure salts are not concentrating in the root zone. If salts do accumulate, management options should centre on increasing the leaching fraction to remove salts from the root zone. This may be achieved by: • Higher water application rates; • Occasional flood irrigation (if practical); • Significant rainfall events; and • Mulching the surface to prevent
evaporation. To prevent capillary rise and evaporative concentration, water application rates should be such that surface wetness is not observed. Given the sandy loam to loam texture of the surface soils, capillary rise may not be a problem as these texture classes typically have large, freely draining pore spaces, which tend to cause downward percolation of applied water. As previously indicated, compaction of the soils can be an issue as these pores can be easily disrupted by tillage, when the soil is too dry or too wet. Vehicular movement (e.g. cultivation operations, spraying) must therefore be undertaken when soil is moist, but not wet, to avoid mechanical compaction of the surface layers. Part of the management should be to use the same wheel tracks wherever possible, as there is some indication the overall soil effects are minimised through this approach.
Prevention of Salinisation of Agricultural and Horticultural Soils Modern agronomic management can minimize salinity impacts in the production cycle through efficient irrigation methods and/or soil treatment. All of the practices planned for the project are designed to
meet this requirement. The following well recognized practices will be used in the horticultural project: • Low volume emitters such as drippers
to minimise irrigation water usage and thus salt build up;
• Soil moisture probes will be installed to enable monitoring of the soil/root wetted zone to ensure adequate, but not excessive, moisture is used;
• Organic matter amendments including humic acid, additional soil organic material e.g. compost is expected to be used to increase soil cation exchange capacity, and improve water holding capacity through enhanced organic matter in the soil root zone;
• Amendments such as calcium will be used to displace sodium from the root zone - chemical analyses of the area’s soils indicate moderate to low sodium cation exchange values, with sodium a very low percentage of the total cation exchange capacity. Although additional salt within the applied water will include sodium, the soil can be maintained at a suitable medium for plant growth without accumulating excess sodium through application of calcium, which displaces the sodium. Commonly gypsum is used for this purpose, and recent common practice is to use micronised gypsum injected into the irrigation systems (commonly referred to as fertigation) and supplied to the soil with the irrigation water;
• Flushing of the root zone will occur during rain periods; and
• Salt tolerant rootstocks will be used for the grapevines and other species where possible to ensure satisfactory plant performance.
While there are some environmental risks in the long term to soil salinisation in using slightly saline water for irrigation on soils within semi-arid and arid zones, the planned use of micro-irrigation and application of well understood agronomic management principles for both soils and irrigation waters is a prudent management
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approach and uses current best management practices. In order to manage the risk of creating soil salinity issues in the long term, it is proposed that an inline monitoring system be in place to monitor salinity levels of the irrigation water, with a view to shutting off supply should salinity levels exceed that required under recycled water use guidelines for irrigation. This approach has ramifications for the horticulture venture (risk of losing continuous supply), however, should shut-down be required, irrigation could occur direct from the pre-SAT pipeline, as is currently seen elsewhere in the region (e.g. Blatherskite Park). This would be a temporary measure only, until salinity of SAT water reaches an acceptable standard for use. It should be stressed that, although this risk needs to be considered, the likelihood of occurrence is low. In summary, it can be concluded that significant long terms impacts to soil salinity and sodicity at the AZRI horticultural site is unlikely to occur, if some basic management practices are employed: • Use of improved irrigation water quality
to that currently used at Blatherskite park and the Tree Lot;
• Use of appropriate irrigation systems; • Addition of gypsum to horticultural
soils to assist in maintenance of soils structure; and
• Occasional over watering to flush salts through the soil layer.
Other options include rotation of crop types and location, to periodically ‘rest’ the soil from irrigation impacts.
Management of Soil Leaching A number of management practices and plant selection practices can have influence on the overall outcome of the system and even then, the soil must be properly drained and adequately leached to prevent salt build-up. Leaching is the deliberate
over-application of irrigation water in excess of crop needs to establish a downward movement of water and salt away from the root zone. This becomes more critical as the soil sodium accumulates or the levels of Total Dissolved Salts of irrigation water rise. The leaching process does not require water of a higher quality (e.g. drinking water) to achieve the aim of mobilising salts, as it is the volume of flow that has the desired the effect. Lower salinity water would assist in dissolving salts, but this is not a vital component. It is proposed that if leaching is required to lessen accumulation of salts in the surface layers of soil, the irrigation water could be used to effect. The predicted volume of irrigation water available and that required for irrigation, is such that there should be volumes in excess of that required, allowing a capacity to use this water for leaching.
Erosion and Sediment Control Some compaction may be impossible to avoid, but traffic should be generally kept to designated road/trail areas and ‘tramlines’ in the cropped areas. Low flotation tyres for equipment may be a prudent option for equipment used in the various construction activities as well as those used in maintenance of the infiltration basins. Soil dispersion can be prudently managed via gypsum application. Additional organic matter levels in the soil may also assist with soil surface structural improvements and assist in minimising compaction and erosion. Additional organic amendments are planned for use in the horticultural project. Some additional organic matter from the recycled water will be deposited in the soil surface zones of the infiltration basins. At the infiltration basins, the walls of the basins will need to be stabilised, to prevent movement of fines into the basins (exacerbating clogging). This can be achieved in numerous ways, including use of erosion control matting or rock reinforcement. It is not recommended that
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the basin sides are stabilised with vegetative cover, as this has the potential to require ongoing maintenance. Each of the basins will require an energy dissipater at the point of inflow to prevent erosion of the basin floor, possibly including a rock or concrete apron type structure (refer to Plate 2). The basins will have a minimum depth of 0.5 metres below the surface, with the individual sub-basins having flat, horizontal floors. Excess soil material could either be mounded around the perimeter or transported off-site. Plate 2 illustrates the shallow nature of the basin
and Plate 3 shows a typical basin during the ‘wet’ cycle. Plate 4 shows another example of SAT basins used in Phoenix, Arizona. The slope of the basin walls should be around 1:2 to reduce the erosion/slope failure of the walls and to provide an easy exit for small animals, which may enter the basins. However, the proposed location for the SAT basins is fully fenced, which will prevent livestock from entering the basins and causing erosion and possible basin floor compaction.
Plate 2: Example of Dissipater at Recycled Water Inlet and Empty SAT Basins. (Source: Dan SAT Project, Israel)
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Plate 3: SAT Basins During Filling. (Source: Dan SAT Project, Israel)
Plate 4: Example of a SAT Basin with Raised Perimeter Walls. (Source: Phoenix, Arizona SAT Scheme)
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Learning from Other SAT and Irrigation Schemes Although the Alice Springs proposal has its own unique characteristics, as the irrigation water will come from stored recycled water in an underground aquifer, it is not an entirely new concept and sufficient expertise is available to manage the agronomic and irrigation issues. There have been a number of recycled water schemes around Australia, including several very successful schemes both north and south of Adelaide, where recycled water is used extensively on vines, for both table grape and wine production. There are also further schemes being developed including one near Cunnamulla, Queensland, that uses recycled and/or high sodium water on vines and citrus. Most of these have direct use of recycled water, rather than water provided from an aquifer. Many projects have been undertaken in climates similar to that of Central Australia, including areas nearby, such as Ti-tree. There have also been many projects world-wide in which the combination of a semi-arid to arid climate has been combined with use of recycled water, with notable development in Israel. There is a range of appropriate experience and expertise to manage the horticulture production in the environment, agronomically and in relation to irrigation technology. Commercial assistance is also available from companies and scientific staff locally and overseas, who have extensive experience with this type of scheme. These include world class companies involved in irrigation technology and application that have operations within Australia, as well as from recycled water research facilities here and overseas. Example sources of expert technical advice and prior experience in similar horticultural schemes include:
• Expert advice from recycled water research facilities in Israel;
• Expert advice from recycled water schemes in Adelaide;
• Development and management of a vineyard at Ti-Tree that used high salinity bore water;
• Development and management of vineyard at Cunnamulla that uses high sodium bore water; and
• Development (in progress) and management of citrus orchard at Cunnamulla that utilises recycled water.
DBIRD also have local research and development expertise and experience from the nearby Ti-Tree horticultural farm area to provide assistance and to help manage off-site impacts.
Summary of Potential Impacts and Safeguards For ease of reference, the identified potential impacts associated with soils and erosion are provided in a summary form in Table 18. To determine the significance of impacts that may occur, Australian Standard 4360 (1999) Risk Management was used (Appendix 4). Using this standard, each potential impact is assessed in terms of the likelihood of occurrence and the consequence of occurrence. The product of these two scores gives an overall risk rating, providing guidance on the significance of the management strategies required.
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Table 18: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Soils and Salinity.Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Erosion ClearingConstructionRainfallOperation
Medium Clear only area requiredMinimise vehicle access to thatnecessaryIncorporate erosion controlmeasures into designStabilise basin walls with wasterock, matting or other suitableinert materialHave basin walls with gentleslope (1:2)Design basin with entry point formaintenance equipmentInclude surge sub-basin indesign of infiltration basins toaccommodate excess waterUse dissipater at point of waterinflow in infiltration basins
Assess clearing extent duringprocessWeekly inspections of allerosion control measuresDaily inspection during rainfallperiodsIn-line monitoring of waterlevels in ponds
Revegetate cleared areasRedesign erosion controlsystems to better suit conditionsModify surface of access roads,where expected high use
SAT
Dust ConstructionClearing
High Minimise vehicle access to thatnecessaryRestrict movement on boundaryfirebreaks to that required forAZRI property managementRevegetate disturbed areasRemove waste soil if notrequired for use on site
Daily assessment of climaticconditions and dust generationduring construction
Cease activity during strongwindsModify surface of access roads,where expected high use
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Compaction ConstructionOperation
High Minimise vehicle access to thatnecessaryFit earthmoving machinery withlow flotation tyres
Weekly inspection of work siteand roadsFinal inspection of basin floors
Rip/furrow/aerate soils,including basin floor afterconstruction, before levelingModify surface of access roads,where expected high use
Change tonutrient status ofsoils
Operation High Annual maintenance to scarifybasin floor and removesediment and organic materialbuild upAlternate sub-basin use
In-line monitoring of recycledwater qualityIn-basin monitoring of soilnutrients
Increase tertiary treatment trainto provide further polishing (e.g.filtration)Cease SAT operations
SATcontinued
Clogging Operation High Conservative basin designUse of 7 day wet/dry cycleAnnual maintenance to scarifybasin floor and removesediment and organic materialbuild up
In-line monitoring of waterlevels in ponds and recycledwater inflow rates to maintainwater levels
Modify wet/dry cycleIncrease frequency of basinfloor maintenanceIncrease pre-treatment ofrecycled water prior to disposalCease SAT operations
Horticulture Erosion ClearingConstructionRainfallOperation
Medium Clear only area requiredMinimise vehicle access to thatnecessaryIncorporate erosion controlmeasures into design
Assess clearing extent duringprocessWeekly inspections of allerosion control measuresDaily inspection during rainfallperiods
Revegetate cleared areasRedesign erosion controlsystems to better suit conditionsSeal access roads, whereexpected high useAugment soils with gypsum tominimise dispersion tendency
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Dust ConstructionClearingOperation
High Minimise vehicle access to thatnecessaryRestrict movement on boundaryfirebreaks to that required forAZRI property managementRevegetate disturbed areas
Daily assessment of climaticconditions and dust generationduring construction
Cease activity during strongwindsModify surface of access roads,where expected high use
Compaction ConstructionOperation
High Minimise vehicle access to thatnecessaryPrevent movement on orworking of soils when wetFit earthmoving machinery withlow flotation tyres
Weekly inspection of work siteand roads
Rip/furrow/aerate soilsModify surface of access roads,where expected high use
Change to soilsalinity andsodicity
Operation High Monitor salinity and sodicity ofirrigation water and soilUse appropriate irrigationtechniques to minimise salinity(e.g. sub-surface drip irrigation)Mulch around irrigation sites toreduce evaporationMonitor delivery rate of irrigationwater – surface soils should notbe visibly wetChoose salt tolerant crops
In-line monitoring of irrigationwater to ensure salinity andsodicity levels acceptableMonitoring of soil parameters,including salinity, sodicity andmoisture
Increase tertiary treatment trainto provide further polishing (e.g.filtration)Leaching of soils through short-term increased flow of irrigationwatersAugment soils with gypsum tomaintain sodicityCease irrigation activities
HorticultureContinued
Change to soilnutrients
Operation High Avoid addition of excessnutrient
Monitoring of soil parameters,including nutrientconcentrations
Cease or modify fertiliseractivities
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
HorticultureContinued
Change to soil pH Operation Medium Augment soils with organicmatter e.g. mulch, to increasebuffering capacityAugment soil with soil pHadjustment products
Monitoring of soil parameters,including pH
Augment soils with appropriatechemical additions to increasebuffering capacityCease or modify irrigation
Further Investigation and AssessmentThe results of the recently completed detailed soil survey should be analysed to determine the exact layout of the proposed horticultural site, keeping in mind therequirements outlined in this PER.
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GROUNDWATER RESOURCES From ad hoc extraction by local residents and farmers prior to World War II, through to the subsequent transition to a centralised drinking water supply and continued irrigation use over the past 60 years, groundwater has provided almost all the water resource needs for Alice Springs and surrounding areas over the past 100 years. Two key outcomes of this important association of groundwater with the ongoing growth of Alice Springs comprise: • Continuing enhancement of the
knowledge and understanding of geological conditions and associated groundwater resources underlying the Alice Springs region to ensure that an adequate supply of suitable quality water is maintained and managed to mitigate existing and potential environmental impacts; and
• Development of community expectations and regulatory requirements to protect and enhance groundwater resources for ongoing and future beneficial uses.
The geology and associated groundwater resources underlying the Alice Springs Region is relatively complex, resulting in
considerable investigation, assessment and reporting over the past 50 years or so on behalf of Power and Water, DIPE and their various Northern Territory and Commonwealth Government predecessors. For the purposes of this PER, the nature of existing groundwater systems and their interaction with the broader environment is primarily presented in a simplified graphical form where possible, supported by written summary descriptions. The Bibliography provided with this PER lists the extensive range of existing studies used to prepare and support the information presented in this section.
Water Protection Zones Water Protection Zones are identified in the Alice Springs Land Use Structure Plan 1999 (ASLUSP) (DIPE, 1999). These were identified in order to allow control over land use and development, in order to protect groundwater resources. Figure 13 shows the three main Water Protection Zones for Alice Springs. The AZRI site sits within the low yielding aquifers of the Amadeus Basin.
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Figure 13: Water Protection Zones of Alice Springs (Source: DIPE, 1999)
Regional Geology & Groundwater Based upon the origin and age of deposition, the geology underlying the Northern Territory has been broken down into the various regions shown on Figure 14. Alice Springs is located adjacent to the boundary of two geological regions, the Arunta Complex to the north and the Amadeus Basin to the south. A larger scale geological map of the Alice Springs area shown in Figure 15 identifies that the Blatherskite Ranges effectively forms the boundary between these two geological regions. Recognisable key facilities located within each geological regions include: • Arunta Complex: Alice Springs
township and wastewater treatment facilities, Ilparpa Swamp and Blatherskite Park; and
• Amadeus Basin: Alice Springs Racecourse and Airport, the Roe Creek Borefield that provides the Alice Springs drinking water supply and the AZRI site.
Figure 16 presents a simplified geological cross-section from Alice Springs to Orange Creek Station, located approximately 100 km to the south west, which shows the general relationship between the older, underlying Arunta Complex bedrock and the younger, overlying Amadeus Basin sediments that are up to 7 km thick.
AZRI
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Figure 14: Underlying Geology in Northern Territory.
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Figure 15: Broad Scale Geology of the Alice Springs Area.
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Figure 16: Geological Cross-section from Alice Springs to Orange Creek Station (Source: Knapton et al., 2004b)
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Arunta Complex The geological units of the Arunta Block mapped in Figure 15 are basically a surface expression of a much larger geological sequence that forms the basement rock for the southern part of the Northern Territory. These geological units consist of highly altered metamorphic and intrusive igneous rocks, such as granite and gneiss. The Arunta Complex is typified by the undulating and uneven rock outcrops and ground surface present over a large area north of the Heavitree Ranges. Groundwater investigations over the past 50 years have determined that the geological units of the Arunta Complex generally do not contain groundwater resources of any great value due to: • Low porosity and permeability of the
rock providing minimal water storage and restricting any economic groundwater extraction; and
• Low groundwater quality that is not suitable for beneficial uses such as drinking water or irrigation.
The key exception is near surface alluvial sediments deposits underlying Alice Springs and the area located immediately south between the Heavitree and Blatherskite Ranges that were primarily formed through erosion and deposition associated with past and ongoing surface water flows in the Todd River. Termed the Town Basin and Inner Farm Basin, respectively, aquifers present within these sediments once provided the drinking water supply for Alice Springs and continue to be used for irrigation of various public open spaces.
Amadeus Basin The Amadeus Basin comprises a series of interbedded sequences of sedimentary rocks, such as sandstone, siltstone, limestone and quartzite, which have been deposited over the much older basement rock of the Arunta Complex. As shown on Figure 16, major ground movements over
geological time have resulted in the undulating wave-type deformation of the sediments of the Amadeus Basin and the bedrock of the underlying Arunta Complex. Termed synclines, these regional-scale structures and the individual rock units play a significant role in the storage and movement of groundwater in the area south of Alice Springs. Although deformed below the ground surface, the Amadeus Basin is typified by the relatively flat open plains associated with more recent Tertiary and Quaternary age sedimentary deposits that have generally in-filled the uneven eroded surfaces of the underlying rock, with occasional outcrops in the form of east-west trending, non-continuous ranges. A number of the geological units that form the Amadeus Basin contain important groundwater resources such as those targeted by the Roe Creek Borefield that are currently utilised for the Alice Springs drinking water supply. The importance of the general groundwater resources present within a large part of the Amadeus Basin and the localised Town Basin and Inner Farm Basin, located within the adjacent Arunta Complex, is recognised through the declaration of the Alice Springs Water Control District by regulatory authorities, the boundary of which is shown on Figure 16.
Local Geology and Groundwater Systems, Flow and Use More detailed geological mapping of the area immediately around Alice Springs, which includes the town centre, Heavitree and Blatherskite Gaps, wastewater treatment ponds, Ilparpa Swamp. AZRI, airport and the Roe Creek Borefield is shown on Figure 17. The geology underlying the area shown on Figure 17 is essentially a localised scale version of the regional geology with the Amadeus Basin
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sediments located south of Blatherskite Range overlying the Arunta Complex rock outcrops present to the north. A simplified, local-scale cross-section from Blatherskite Gap to South of the Alice Springs Airport presented in Figure 18 identifies all the relevant geological formations containing groundwater resources in the area of the proposed SAT scheme or horticultural extraction and irrigation within the AZRI site. Descriptions of these relevant geological formations, from oldest to youngest and
their associated groundwater resources, known recharge and discharge sources and current uses are provided in Appendix 5. The following sections that discuss potential impacts upon key groundwater systems that currently provide drinking water supplies for Alice Springs and may be impacted by the proposed SAT and horticultural schemes and/or other potential pollution sources should be read with reference to the Figure 18 cross-section and the additional detail provided in Appendix 5.
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Figure 17: Geology of Alice Springs.
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Figure 18: Geological Cross-section from Mt Blatherskite to the Alice Springs Airport. (Source: Knapton et al., 2004b)
Potential SAT and Horticulture Scheme Impacts
Drinking Water Supply Rock Formations Alice Springs obtains its drinking water supplies from three key rock formations (Shannon Formation, Parcoota Sandstone & Mereenie Sandstone) that are overlain by more recent Tertiary and Quaternary aged sediments over most of the Amadeus Basin. Existing monitoring and investigation data demonstrates that there is no groundwater flow connection between groundwater present within Tertiary sediments and the underlying drinking water supply rock formations. An appropriate example of this is shown in Figure 19 that demonstrates that groundwater levels present within the Tertiary Sediments have been rising to some degree since the mid 1970s whilst at the same time groundwater levels within the various underlying drinking water supply rock formations have been steadily falling as a result of extraction by tens of
metres in the same time period. Given the volume of water extracted for drinking water supplies, any groundwater connection to the overlying Tertiary aquifers would have resulted in a decrease in groundwater levels. Another example is the typical age of the groundwater present in the underlying rock formation aquifers being many thousands of years, indicating that changes to surface water or near surface groundwater systems within the alluvial sediments, such as the proposed SAT recharge scheme, will have no measurable impact upon the underlying rock formation aquifers and associated drinking water supplies for Alice Springs and the surrounding area. On this basis, the various drinking water supply groundwater systems underlying the Tertiary and Quaternary sediments are not discussed further.
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Figure 19: Changes in Groundwater Height and Rainfall 1957 to 2003. (Source: Knapton et al., 2004a)
Tertiary Sediments The Tertiary sediments primarily comprise low permeability clays that provide little or no groundwater resources. The exception is a series of up to four semi-continuous, horizontal lenses of sand, no more than 2 m thick and ranging in depth between 50 m and 100 m. These sand lenses predominantly receive recharge through hydraulic connections with the Bitter Springs Limestone along Blatherskite Range. The sand lens aquifers are confined by overlying clay layers approximately 30 m thick as demonstrated within the AZRI site by a groundwater pressure head of approximately 18 m within the upper sand lens that is present at a depth of approximately 50 m. The general
flow directions and movement of groundwater within the Tertiary sediments is not well understood. Groundwater quality within the Tertiary Sediments is generally only suitable for a range of irrigation purposes. Extraction of groundwater for this purpose occurs within the AZRI site and also by various residential properties located along the eastern boundary of the AZRI site. Monitoring data indicates that salinity levels are increasing within the upper Tertiary aquifer. The mechanism for this increase is not well understood, however, investigations carried out for the AZRI site
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indicate that old or poorly constructed irrigation extraction bores may be providing a direct hydraulic connection to relatively high saline groundwater present in overlying alluvial groundwater systems. It is also possible that irrigation extraction of groundwater exceeds natural recharge, thus drawing more saline water from the Bitter Springs Formation.
Quaternary Sediments An Honours thesis prepared by Jeuken (2004) documents and interprets groundwater flow paths and quantities within Quaternary sediments present across the Inner and Outer farm basins, focusing on the AZRI site area. The resulting conceptual model of alluvial sediment groundwater movement is summarised in Figure 20. The key recharge sources for the Inner Farm Basin comprise: • Discharge from the Town basin
through Heavitree Gap; • Surface water flow events within the
Todd River; and • Infiltration of seepage from the various
water treatment and storage ponds (considered the predominant recharge source).
The key recharge sources for the Outer Farm Basin palaeochannel through the AZRI site comprise: • Discharge from the Inner Farm Basin
through Blatherskite Gap (considered the predominant recharge source). Average groundwater flow velocities of 1.5 m/day (700 m/year) have been estimated;
• Surface water flow events within the Todd River and St Mary’s Creek; and
• Some upward groundwater movement from the underlying Tertiary Sediment aquifers.
The recharge sources overlain with alluvial groundwater contours for the Outer Farm Basin demonstrate that the preferential groundwater flow paths generally follow the
nominal alignment of a palaeochannel feature identified on Figure 21 that extends from Blatherskite Gap, across the AZRI site to the south eastern corner at Colonel Rose Drive. The location of the palaeochannel and groundwater flow direction beyond Colonel Rose Drive is currently not well understood. It has been theorised that it would continue in a south east direction, rejoining the current Todd River channel further down stream. Further investigation is required to determine this. Areas of deeper alluvial sediments along palaeochannel within the Town Basin and Inner Farm Basins receive recharge from surface flows in the Todd River and consistent seepage from the wastewater treatment ponds. This combination of conditions provides substantial groundwater resources with salinity levels that are currently suitable for extraction for irrigating a range of public open spaces throughout Alice Springs. Beyond the zones influenced by the relatively low salinity surface recharge sources, groundwater salinity concentrations increase to the point that use of groundwater from either the Town Basin or Inner Farm Basin for irrigation purposes is not possible. Originally both the Town Basin and Inner Farm Basin contained areas of groundwater, particularly along palaeochannels, with suitable quality within the zone of influence of Todd River recharge that they provided the Alice Springs drinking water supply until the mid 1960s. Following the introduction of the Roe Creek Borefield and the cessation of drinking water extraction from these aquifers, groundwater levels subsequently increased in the 1970s above natural levels, resulting in salinisation and the Town Basin and Inner Farm Basin becoming unsuitable for drinking water extraction. Increasing groundwater extraction for irrigation use from the Town and Inner Farm Basins was one of the strategies adopted in an attempt to manage groundwater levels and reduce ongoing salinisation. Maintaining existing groundwater discharge quantities from the Town Basin through Heavitree Gap and
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from the Inner Farm Basin through Blatherskite Gap also provides a key groundwater level and salinity management mechanism. Groundwater recharge and flow conditions within the Outer Farm Basin are considered to be different to the Town Basin and Inner Farm Basin aquifers. The palaeochannel section of the Outer Farm Basin, containing the main groundwater resources, is located further away from natural recharge from the Todd River. Direct recharge from low salinity surface flows is therefore reduced. Also, there is no confining mechanism directing groundwater flow through narrow
gaps within the deeper sections of the aquifer. Although the palaeochannel is considered to be the main flow pathway within the Outer Farm Basin, groundwater flow will occur in shallower or thinner aquifers over a widespread area south of Blatherskite Gap. As a result of these conditions, groundwater resources present within the palaeochannel within the Outer Farm Basin are therefore less reliable and have a greater salinity. At present there are no registered users of the Outer Farm Basin alluvial aquifer and it is not considered to have any existing beneficial use.
Figure 20: Conceptual Model of Recharge Sources, Recharge Rates, Flow Paths and Chemical Processes Occurring at AZRI. (Adapted from: Jeuken, 2004)
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Other Potential Upstream Pollution Sources The proposed SAT scheme infiltration area is located downstream from a number of developments that could potentially affect existing or added groundwater, with the geology of the area indicating linkages between these potential pollution sources.
Salinity There has been an accumulation of salinity in the groundwater immediately north of Heavitree Gap and this nominally slowly flushes through the Gap to move further downstream. While the course of the movement is predominantly within the current bed of the Todd River, there is a small possibility of greater volumes of this also moving sub-surface through the palaeochannel continuing to raise salinity in the existing groundwater and added infiltration water. It is a source of some salinity already.
Groundwater Movement from Blatherskite Park Over the past 20 years, the irrigation at this site has led to the development of a slowly moving plume of saline groundwater which is moving south east into and potentially then down the palaeochannel, ultimately to migrate into the aquifer below the proposed activity sites. While not considered in detail for this project, improvements to the recycled water quality and irrigation method are proposed for Blatherskite Park, which would lead to longer term moderation of the developing plume of groundwater. However, it is estimated to be several decades at present indications before this groundwater plume would potentially directly impact the groundwater underlying the project site.
Monitoring of the situation is recommended and intervention may be warranted at a later period.
Overflows from Ilparpa Swamp Removing the dry weather wastewater flows into Ilparpa Swamp is expected to curtail the regular overflows that have occurred. However, it is probable that periodic inundation of the swamp through episodic rainfall events may still cause overflows. This would more closely resemble the former natural cycles and while some water would flow into the ground this is considered a minor pollution source.
Alice Springs Racecourse The racecourse has a sand/oil track and stables plus the usual range of activities on the site, including human activities. Oil used for the track is of vegetable origin, not mineral, and does not have the same potential to pollute groundwater as it tends to break down reasonably quickly in the warm environment. While there is some movement of detritus from horses and other animals, most of this material is transformed into organic enhancements in the near soil surface layers and is not a significant pollution issue. Use of recycled water in larger volumes at this site in future, for example to grow crops on the site, may have broadly similar issues in relation to soil and management to the use of the recycled water for horticulture or agriculture at the proposed sites at AZRI. Flushing to groundwater required for management could impact or disrupt the systems already in place downstream.
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Desert Knowledge Precinct and Existing Infrastructure at CSIRO Activities at this development are initially likely to include buildings and some additional vehicle movements. Any additional pollution sources are likely to be surface contaminants, which would be removed downstream via overland flows and attenuated through infiltrating the ground. While there is a need to minimise pollution sources, the planned developments are considered of to have minimal impacts. In the longer term additional development may occur in the area between AZRI and the Old Timers Home and this would need careful consideration in relation to the proposed SAT scheme.
Further Investigation and Assessment The southern extent of the palaeochannel and the location of its rejoining with the Todd River is currently unknown. It would be desirable over the long term to undertake hydrogeological investigations to determine the path of the palaeochannel as it leaves the AZRI site, so that preferential movement of infiltrated recycled water could be monitored. This requirement can occur over the longer term given the estimated amount of time required for infiltrated recycled water to move substantial distances under an extraction programme.
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SAT OPERATION AND MANAGEMENT Palaeochannel Characterisation Power and Water commissioned or supported a series of studies of the Outer Farm Basin palaeochannel to determine its suitability for the Alice Springs Water Reuse Scheme SAT project. The outcomes of these studies and findings with respect to the suitability for use of SAT technology at the AZRI site are described in the following sections.
Site Investigation Knapton and Lennartz (2004) describe site investigations of the palaeochannel through
the AZRI site to determine its suitability for water banking and recovery. The investigations confirmed the presence of alluvial sediments overlying a relatively uniform surface of Tertiary clays at a depth of approximately 18 m below ground level. A semi-linear erosion palaeochannel was identified over a width of between 200 m and 400 m, as shown on Figure 21, containing coarse grained quaternary sediments incised into the Tertiary sediments to a depth of approximately 30 m below ground level.
Figure 21: Groundwater Contours and Palaeochannel within AZRI Site (Adapted from Knapton et al., 2004b)
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A typical cross section of the alluvial sediments and palaeochannel are shown on Figure 22. In summary the alluvial sediments comprise: • Layer 1:
An surface topsoil layer to a depth of 1 m to 2 m containing silts and clays with variable sand content;
• Layer 2: An upper, more porous and permeable layer of sands and gravel to typical depths of 3 m to 5 m, with a thickness of 1 m to 2 m;
• Layer 3: A less porous and permeable sandy silt layer to typical depths of 7 m to 9 m;
• Layer 4: A middle, more porous and permeable layer of silty sand and gravel to typical depths of 9 m to 11 m, with a thickness of 1 m to 2 m;
• Layer 5: A relatively thick layer of low porosity and permeability silts and clays to a depth of approximately 18 m; and
• Layer 6: A lower, more porous and permeable layer of interbedded sandy gravel, sandy silt and gravelly cobbles generally limited to a thickness of 1 m to 2 m, except along the palaeochannel where this layer extends to a depth of approximately 30 m with a thickness of between 6 m and 12 m.
The depth and thickness of these various layers is relatively consistent, regardless of changes in surface elevations, indicating that the individual layers described above may only be semi-continuous and interconnected across the AZRI site.
Figure 22: Geological Cross-section through Palaeochannel. (Source: Knapton et al., 2004b)
386000 mE 386500 mE 387000 mE 387500 mE 388000 mEChainage (metres)
520
525
530
535
540
545
550
555
560
Elev
ation
(mAH
D)
RN179
94
RN17993
RN179
91
RN17978
RN17980
RN17973
RN17989
QUATERNARY UNCONSOLIDATED SEDIMENTSSILTS, SANDS AND GRAVELS
SILT/CLAY(Top Soil) SILT/CLAY sandy SILT gravelly SILT sandy GRAVEL
with basal COBBLES CLAY
TERTIARYUNCONSOLIDATEDCLAYS
WEST EAST
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Groundwater level measurements presented on Figure 22 show that there is a relatively steep decrease along the palaeochannel from approximately RL 555 m AHD at the boundary between the Inner and Outer Farm Basins through Blatherskite Gap to less than RL 535 m AHD towards the south east corner of the AZRI site. Given the relatively flat ground surface and presence of a confining clay layer between the palaeochannel and underlying Tertiary aquifers, this relatively steep gradient is a clear indication of the capacity of the Outer Farm Basin sediments to dissipate groundwater predominantly through high through flow rates and the absence of other existing major recharge sources. Existing water quality in the palaeochannel varies along its length from moderately to highly saline. As shown on Figure 22, the groundwater investigations indicate that the main, more permeable gravel layer present within the palaeochannel (Layer 6) is generally fully saturated and possibly semi-confined by the overlying clays/silts (Layer 5). It is therefore possible that surface infiltration through upper layers may be restricted into the palaeochannel. The presence of a semi-confining layer may also impact upon the ability to recover infiltrated water. It should be noted, however, that previous studies for the Town and Inner Farm Basins have also indicated similar wide spread layering conditions and possible semi-confined conditions within the palaeochannels. Practical experience in these systems have identified that the fined grained confining layers are only semi-continuous and that the coarse grained layers are generally well interconnected and, on a broad scale, aquifers are effectively considered to be unconfined.
Infiltration Trials Infiltration suitability and capacity at the AZRI site have been subject to two interrelated studies:
• Laboratory scale column testing that primarily focused upon mechanisms for near surface soil clogging the minimum water quality required to maintain adequate infiltration capacity; and
• Field scale infiltration trials located within the AZRI site that focused on the hydraulic behaviour of infiltrated water within near-surface soils and impacts upon underlying groundwater levels and flow pathways.
Both studies targeted the main two near-surface soil types that have been identified within the palaeochannel area of the AZRI site comprising silty sand or loam that reflect overflow channel areas and more coarse sand/gravel material which coincides with relic drainage features. Both studies were also operated using a nominal sequence of four consecutive cycles of wetting and drying over one week time intervals. In addition to the two soils types, the laboratory column tests included a range of variables: • Four different water sources:
o Alice Springs drinking water; o Alice Springs recycled water used
to irrigate Blatherskite Park; o Alice Springs recycled water used
to irrigate Blatherskite Park with additional rock filtering; and
o Adelaide recycled water subject to secondary treatment including dissolved air flotation.
• Variable water ponding depths of 100 mm, 300 mm and 500 mm; and
• Constant temperature and variable temperature glasshouse conditions.
Key findings from the laboratory scale study comprised: • Soil clogging from both physical (i.e.
suspended solids) and biological (i.e. algal growth) occurred to some degree with all four water types and other variable conditions;
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• Use of both types of Alice Springs recycled water resulted in greater soil clogging with physical process being predominant. Higher quality Alice Springs drinking water and Adelaide recycled water resulted in less clogging with biological impacts being predominant. Infiltration rates at the end of the laboratory trials were an order of magnitude greater using the secondary treated Adelaide recycled water (4 m/day for sand and 0.5 m/day for loam) compared to the existing Alice Springs recycled water (0.3 m/day for sand and 0.04 m/day for loam). The biological component of soil clogging was greater in waters with higher nutrient concentrations;
• A significant proportion of the reduction in infiltration rates for all four water types generally occurred within very short time periods (<1 day). The effectiveness of the wetting and drying cycle increased where physical clogging was the predominant factor (i.e. lower quality treated water containing suspended solids);
• Clogging was generally concentrated towards the top few centimetres of the soil. Increasing the depth of ponding was found to decrease infiltration rates through a combination of compaction of the clogging layer and increased the penetration of clogging material into the soil profile. As a result of this finding, the study recommended that ponding depths be kept below 300 mm to maximise infiltration rates and the efficiency of the wetting and drying cycles that only impact upon the upper soil layers; and
• Improvements in water quality identified were generally limited to the removal of suspended solids and dissolved organic carbon only due to the relatively limited thickness of the columns used. Only one of the three water treatment processes identified with SAT schemes was allowed to occur.
Field scale infiltration trials comprised the construction of two 6 m x 6 m infiltration
basins located within AZRI and the use of Alice Springs drinking water with a maximum inflow rate of 4.5 L/sec. A series of nested groundwater monitoring wells were constructed into each of the more permeable layers below each basin to measure and track changes in infiltration movement down to the existing groundwater table and any subsequent mounding effects. Key findings from the field scale trials comprised: • The average infiltration rates for each
basin were 3.2 m/day (silty sand/loam) and 10.6 m/day (sand/gravel). The first basin located on the silty sand/loam material readily reached the nominal operational depth of 300 mm with an average water inflow rate of 2 l/sec. The infiltration capacity of the second basin constructed on the sand/gravel material was generally greater than the available water supply, with a maximum depth of 200 mm reached with a flow rate of 5.5 L/sec.
• No identifiable clogging or loss of infiltration capacity was measured within either basin during the field infiltration trials. The variation in infiltration rates between the two trial basins was considered to be the result of different underlying shallow soils;
• Flow processes within the unsaturated zone above the palaeochannel were identified as being relatively complex. Perched saturated water conditions did develop to varying extent within the two shallow more permeable layers (Layer 2 & Layer 4). Perched water levels in Layer 2 generally stabilised after one day and dissipated rapidly during the drying cycle. Perched water in Layer 4 took 3 to 4 days to stabilise, with a residual mounding of 2 m to 3 m maintained during the drying cycle. Some lateral movement of infiltrated water was observed to occur within both perched layers, including interconnection between the sediments underlying the two trial basins;
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• Infiltrated water was considered to migrate relatively rapidly through the various soil profile layers into the deeper palaeochannel. During the field trials maximum groundwater mounding of 0.5 m observed in the palaeochannel groundwater system. Based upon the estimation that approximately 13 ML out of the total 18 ML of infiltrated water reached the palaeochannel aquifer, a transmissivity of 250 m2/day within the palaeochannel has been calculated. This finding compared favourably with previous studies of the palaeochannels present within the Town and Inner Farm Basins;
• A vertically decreasing hydraulic gradient in soils underlying the basin was observed, with hydraulic heads below the base of the basins at almost all times. Perched groundwater levels fell quite rapidly at the commencement of each drying cycle, although moisture contents generally did not decrease greatly during the drying period.
Although overall the field infiltration trial study concluded that the palaeochannel feature and overlying sediments were suitable for the operation of the proposed initial SAT scheme, the study did also identify a number of limitations that would require further study and or management during the introduction of the initial SAT scheme: • The existing groundwater monitoring
bore network was considered inadequate to accurately identify the spatial distribution of the groundwater mound in the palaeochannel and the development of perched systems and possible lateral groundwater movement within the various overlying soil layers;
• Monitoring bore construction techniques had the potential to allow direct hydraulic interconnection between the upper soil layers and the palaeochannel, short circuiting natural flow paths and processes.
Groundwater Movement Modelling Based upon the findings of the site investigations, field infiltration trials and previous experience with groundwater movement within palaeochannels located in the Town and inner Farm Basins, a relatively simple three dimensional groundwater flow model was prepared for the AZRI site. The purpose of the model was to estimate the potential impact on groundwater levels and flow below the proposed infiltration basins during the 600 ML/year initial programme and to identify issues of concern that may impact upon the viability of the initial programme and/or possible requirements for further investigation or monitoring. The model developed describes a simplified concept of an unconfined aquifer system primarily located along a nominal channel incised into the underlying Tertiary Sediments overlain by a uniform layer of lower permeability sediments. The modelling was carried out in four key steps: • Programming an initial model reflecting
known geology and groundwater physical parameters and anticipated boundary conditions;
• Calibration of the model in both steady state and transient state to match observed water level data. Model conditions were subsequently changed to match ongoing groundwater discharge anticipated from the Inner Farm Basin through Blatherskite Gap;
• Undertaking a sensitivity analysis to assess which key model assumptions have the greatest impact upon performance of the model. The main parameter influencing the performance of the model was hydraulic conductivity. An order of magnitude decrease in hydraulic conductivity results in an order of magnitude increase in groundwater mounding below the infiltration basins.
• Modelling the impact on groundwater from the proposed operation of the 600 ML/year SAT scheme. The modelling looked at infiltration rates of 0.3 m/day
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and 3 m/day as identified by the laboratory and field infiltration trials.
Key outcomes of the modelling process comprised: • The infiltration rate of 3 m/day requires
a total basin area of 1,100 m2, and results in a nominal maximum groundwater mound height of 7.8 m above existing groundwater levels with a radius of influence extending beyond the boundaries of the AZRI site (refer Figure 23). The infiltration rate of 0.3 m/day requires a total infiltration area of approximately 12,000 m2 and results in a nominal maximum groundwater mound height of 6 m above existing groundwater levels and a similar radius of influence as above (refer Figure 24);
• The volume of water entering the Outer Farm Basin through Blatherskite Gap from the Inner Farm Basin is not anticipated to be impacted by the SAT scheme. It must be noted, however, that groundwater levels are anticipated to increase to some extent at the boundary discharge point;
• Under both infiltration scenarios, the depth to groundwater below the AZRI
site and adjacent topographic low points (i.e. Todd River) are estimated to be greater than 10 m, indicating that near surface ground saturation or discharge and associated potential salinity issues will not result from the operation of the initial SAT scheme;
• The predominant flow direction from the infiltration basins is directly along the palaeochannel feature to the south east corner of the AZRI site. Lateral movement perpendicular to the main flow direction has been estimated to be relatively small and contained largely to the palaeochannel feature that is approximately 400 m wide;
• The plume of infiltrated water is estimated to move down gradient at approximately 300 m/year, providing approximately 3 to five years before the infiltration water extends beyond the AZRI boundary;
• Extraction of a similar volume of water from the palaeochannel immediately down-gradient of the infiltration ponds would result in the infiltration plume being contained to the immediate area, with almost no down gradient movement anticipated (refer Figures 25 and 26).
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Figure 23: Groundwater Mounding Height Contours of Steady State Infiltration at Rate of 3 m/day (600 ML/yr). Shows metres above ambient condition (Source: Knapton, 2004b)
Horticulture Block
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Figure 24: Groundwater Contours of Steady State Infiltration at Rate of 0.3 m/day (600 ML/yr). (Source: Knapton, 2004b)
Horticulture Block
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Figure 25: Particle Tracking Results for Calculated Layer 2 from Steady State Infiltration Response to 640 ML/yr into ‘Kidney’ Shaped SAT Basin Design. (Source: Knapton, 2004b)
Horticulture Block
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Figure 26: Infiltration through Rectangular Basins at 600 ML/yr and Combined Extraction from Four Bores Along Palaeochannel. (Source: Knapton, 2004b)
Groundwater Quality The current water quality of groundwater in the area planned for horticulture is considered both of low quality and low potential for extraction with relatively low bore flow rates and nominally considered of poor quality for horticulture. Quality is variable within the general area but commonly in the 1,200 to 1,800 mg/L Total Dissolved Salts (TDS) range at bore pumping rates of 1 to 2 litres per second, sometimes lower.
The proposal is to use recycled water of a quality of around 800 to 1,000 mg/L TDS that will be infiltrated in the SAT scheme, and on extraction, the recycled irrigation water is expected to be around 1,000 mg/L. A general principle is that, use of irrigation water with a TDS value at below 500 mg/L, provides no noticeable detrimental effects on plants and the soil. At between 500 and 1,000 mg/L TDS in the irrigation water, there can be effects on sensitive plants. At 1,000 to 2,000 mg/L, TDS levels can affect
Horticulture Block
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many crops and careful management practices should be followed. With irrigation waters above 2,000 mg/L, water can be used regularly only for tolerant plants on permeable soils. The expected water quality of the water extracted from the SAT scheme and used for irrigation is likely to be around 1,000 to 1,200 mg/L TDS. The proposed horticultural use of primarily grapevines is consistent with the expected resultant irrigation water quality.
SAT Scheme Suitability Table 19 provides a summary of site characteristics of operational SAT projects for selected international sites. The key design components of the AZRI site comprising soil types, infiltration rates and depth to underlying groundwater conform well to the conditions at SAT sites that have been operational for generally at least 30 years. Variations to key sub-surface conditions typical of the international SAT projects that are present at the AZRI site comprise: • Containment of the main groundwater
storage and flow aquifer to a semi-linear palaeochannel. Compared to other operational sites this limits the potential groundwater storage capacity and greatly increases the reliance on down-gradient groundwater through flow to provide adequate groundwater
storage for the proposed infiltration volumes. One advantage of the geological conditions and preferential flow pathway is greater potential to contain, intercept and extract stored infiltrated water in a known area; and
• The presence of variable layers of interbedded lower and higher permeability soils overlying the main groundwater storage aquifer. Most of the other SAT scheme are underlain by relatively uniform soil conditions that allow a consistent, uninterrupted, vertical downwards flow from the basin floor, through the unsaturated zone to underlying groundwater. Experience at international SAT schemes where perching of groundwater does occur have identified lateral movement of infiltration water beyond the basin foot prints, even to the extent where interference to the wetting and drying cycle of adjacent basins or full saturation of the vadose zone may occur. In such cases SAT treatment and infiltration efficiencies have generally been maintained through modifications of the wetting and drying cycle.
The variations in sub-surface conditions at the AZRI site will require specific assessment and implementation of management measures to maintain appropriate infiltration flow mechanisms below the proposed basins.
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Table 19: Summary of Site Characteristics for SAT Schemes.Location Project Name Operation
Duration (yrs)Area (ha) Volume Processed
per Year (ML)Soil Type Infiltration Rate
(m/day)Depth to WaterTable (mBGL)
Flushing Meadows 37 0.78 155.4 Loamy sand 0.23 3Arizona, USA23rd Avenue Project 29 16 8,000 Sand and gravel 0.14 15
California, USA Montebello Forebay 42 263.5 61,650 Sand and gravel 0.064 VariableIsrael Dan Region Project 27 41.7 98,550 Fine sand 0.13-0.2 32Alice Springs AZRI N/A 1.5 600 Loam sand 5.1-44.5
(prior to clogging)16
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Potential SAT Impacts
Existing Groundwater Uses Extensive monitoring and assessment of groundwater resources present around Alice Springs over the past 50 years, as summarised in Appendix 5, clearly demonstrate that the proposed SAT scheme at the AZRI site will have minimal or no impact on aquifer systems beyond those present in the underlying Tertiary and Quaternary Sediments. No significant risks to the drinking water supplies for Alice Springs extracted from underlying rock formations that could results from the proposed SAT scheme have been identified. The thickness and consistency of Tertiary clay sediments underlying the palaeochannel and other Quaternary sediments is also anticipated to restrict vertical migration of SAT infiltration water and provide protection to the minor groundwater Tertiary aquifers present at depth and currently used both within the AZRI site and adjacent residential properties for non-drinking water irrigation purposes. A possible limitation to the protection of the Tertiary aquifers is existing network of extraction wells. Poor construction and the age of some of these bores within the AZRI site have already been identified as possible mechanisms for the direct hydraulic connection between the Tertiary Aquifer and existing lower water quality present in the Quaternary sediments. Increased groundwater levels in the Quaternary sediments resulting from the operation of the SAT scheme has the potential to increase migration rates through the bore annulus of lower quality native and/or infiltrated recycled water into the Tertiary aquifers. The infiltrated recycled water is not considered to be a concern as it will have been treated to a standard suitable for existing irrigation uses within the AZRI site and adjacent residential properties. The potential
increase in naturally saline groundwater migration into the Tertiary aquifers has the potential to result in unacceptable loss of groundwater quality. Monitoring will be required to identify such impacts. Where adverse impacts are identified, intervention in the form of alternative irrigation water supplies or sealing or replacing inadequate bores may be necessary. The existing large hydraulic head difference between the Inner Farm Basin and Outer Farm Basin will protect the Inner Farm Basin from reverse migration of existing higher salinity groundwater present within the quaternary sediments. Groundwater modelling indicates that groundwater flow along the palaeochannel will almost double in volume from operation of the SAT scheme, increasing the discharge of saline water outside the AZRI site to the south. Potential risks or impacts from such changes to the groundwater flow regime are considered to be low on the basis of the following: • There are no known current
groundwater users or beneficial uses of shallow groundwater resources south of the AZRI site; and
• The generally increasing depth to groundwater and anticipated discharge capacity of the palaeochannel to the south should limit the potential for saline groundwater levels increase to the point where surface discharge and/or near surface water logging could occur.
It has been recognised, however, that further investigation is required to determine the nature, extent and location of the palaeochannel beyond the AZRI site. This would provide definitive sub-surface information to demonstrate that impacts upon other groundwater resources and downstream surface water features are unlikely to occur or impact on any future
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beneficial use down gradient from the AZRI site.
Water Logging and Salinity Based upon experience in both the Town Basin and Inner Farm Basin since the 1970s, a key concern for this project is the potential to raise groundwater levels within the Quaternary sediments at or near surface level, resulting localised water logging and dryland salinity impacts. Such a scenario resulting from the proposed SAT scheme, where the AZRI site and surrounds have minimal topographical relief would be considered unacceptable. The lowest topographical feature is the Todd River located to the north east of the AZRI site, whilst the AZRI site itself contains a number of lower lying drainage channels. These topographic lows are considered to be the main areas of concern for water logging and dryland salinity impacts. The findings from the field infiltration trials and subsequent groundwater modelling for the SAT project have provided a high level of confidence that general groundwater levels within the Quaternary sediments will remain at least 10 m below the ground surface. Under such conditions, water logging and dryland salinity are not likely to result from the SAT scheme. Sensitivity analysis undertaken for the groundwater modelling did identify that anticipated groundwater levels were directly correlated to the transmissivity of the palaeochannel. A significant reduction of transmissivity from that identified to date would, could potentially result in unacceptably high groundwater levels. The proposed groundwater monitoring programme will need to be designed to both identify ongoing changes in groundwater levels and allow re-estimation of the palaeochannel transmissivity following introduction of the SAT scheme. Based upon the geological conditions and findings of the field infiltration trials, some lateral movement of infiltration water in very shallow perched groundwater layers is anticipated. In the trial such movements were generally found to be minor and quickly reached steady state conditions to
allow vertical infiltration through underlying lower permeability soils. For a larger scheme it should be recognised that there is a limited potential for some localised ground seepage to occur along preferential flow pathways within the immediate vicinity of the infiltration basins. Widespread monitoring of near-surface groundwater levels and ongoing visual observations will be required to identify such conditions. Where such conditions are identified, intervention of the form of one or more of the following management solutions may be required: • Installation of localised drainage bores
to intercept near surface lateral flows. These could be constructed to allow gravity drainage into deeper soil layers or could be in the form of spear points or similar with the collected water pumped back into the infiltration basins;
• Installation of localised low permeability barriers to block near surface preferential flow pathways. A barrier could be achieved through injection of grout into the soil or excavation and placement of low permeability clay material.
Effect of Extended Residence Time on Recharged Water Quality Once the infiltration water has entered the storage aquifer it will remain in the aquifer until its withdrawal from the extraction bores. The time between these events is known as 'residence time'. In groundwater the actual period of residence time can affect changes in water quality. These changes may be related to a range of factors including pressure, temperature or the chemical nature of the geological make up of the aquifer (e.g. limestone, sand, gravel etc.). A recent study by Jeuken (2004) found that recycled water disposal at Blatherskite Park resulted in rapid and effective removal of bacteria from recycled water as it travelled through the soil layer but was unable to determine if further 'polishing' occurred due to residence time in the aquifer proper. Thus, the role of residence time on microbiological
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attenuation is undetermined. Nonetheless it is well recognised that extended residence time assists in the decrease of microbiological risks associated with groundwater extraction. Knapton et al. (2004b) cite European groundwater management where 50 days retention time was considered sufficient for the microbiological protection of consumers. Jeuken (2004) also found little change in the chemical composition of groundwater in the vicinity of Blatherskite Park due to changes in the storage aquifer. In the context of the proposed SAT scheme, no detectible changes to water quality are likely to due to residence time. One factor that may be evident could be the mild stratification of the aquifer due to the lower salinity of the infiltrating water compared to that of the native groundwater. This difference will mean that the infiltrating SAT water will be marginally less dense than the native groundwater and may tend to 'float' on top of it. Nonetheless, hydraulic perturbation in and around the extraction bores will tend to disrupt stratification through localised drawdown and mixing near the off-take regions of these bores.
Proposed Safeguards
Groundwater Monitoring Monitoring changes to groundwater levels and chemistry will be crucial to assessing and effectively managing each of the key components of the water reuse scheme within the AZRI site. Potential impacts and changes that need to be considered include: • Increasing groundwater levels and
potential lateral movement due to possible perched conditions below the SAT basins that could result in water logging and surface water discharge;
• Mixing of infiltrated recycled water and existing groundwater and anticipated improvements to groundwater quality and subsequent suitability for extraction and reuse;
• Groundwater flow and quality within alluvial sediments outside the immediate SAT scheme area; and
• Increased migration of existing saline groundwater present in alluvial sediments through poorly constructed or old bores used to extract groundwater from underlying Tertiary sediments within the AZRI site and adjacent rural residential properties.
The existing network of monitoring bores requires extension to enable collection of comprehensive information from four distinct levels within the sub-surface to demonstrate that the objectives of enhanced water treatment, environmental protection and opportunities for reuse are achieved and to support ongoing effective and efficient management of the SAT and ASWRUS schemes: • Alluvial Layer 2:
Within the more porous and permeable layer of sands and gravel to typical depths of 3 m to 5 m;
• Alluvial Layer 4: Within the more porous and permeable layer of silty sand and gravel located above the main low permeability clay cap overlying the palaeochannel to typical depths of 9 m to 11 m;
• Alluvial Layer 6: Within both the main palaeochannel to depths of approximately 30 m and the more widespread layer outside the palaeochannel to depths of approximately 20 m; and
• Tertiary Aquifers: Within the upper thin layers of sand material located at depths of approximately 50 m and greater below the overlying sequence of low permeability clays;
The monitoring bore network should be positioned to target the three alluvial layers at the following locations: • Immediately below the SAT infiltration
basins (nominally 4 sets of bores);
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• Immediately adjacent to the SAT infiltration basins (nominally 6 sets of bores);
• Adjacent to the aerial extent of the palaeochannel feature within the AZRI site around the infiltration basins (nominally 6 sets of bores); and
• Adjacent to the boundary of the AZRI site with the rural residential properties, Colonel Rose Drive and Todd River and an equivalent distance to the west of the infiltration basins within the AZRI site (nominally 8 sets of bores).
As the concern with the Tertiary aquifers is migration of relatively saline groundwater down existing extraction bore annuli, the most appropriate monitoring locations will be the existing bores. Where access is available, the monitoring programme will include each of the existing Tertiary extraction wells located within the AZRI site and a representative selection of six
extraction wells within the adjacent rural residential properties. A sampling and analysis programme for a suite of contaminants including major ions, metals and nutrients will commence before infiltration commences to measure ambient groundwater concentrations. It will need to be recognised in assessing monitoring results that there is a possibility that mobilisation of salts will occur as a first-flush effect in the soil profile. This will dissipate as serial dilution continues through the profile. Two water quality monitoring components will be required for the SAT scheme, to cover both: • The commissioning stage covering the
first three years of the project (Table 20); and subsequently
• The operational stage of the project (Table 21).
Table 20: Groundwater Monitoring during Commissioning Parameter Suggested Determinants Frequency of
testing per year Site(s)
Heavy Metals Al, As, B, Cu, Cd, Cr, Zn (as minimum suite)
4 Monitoring bores
Dominant ions Ca, Na, K, Cl, SO4, HCO3 4 Infiltration ponds and monitoring bores
TDS Conductance (25°C). Calculation based on above.
12 Infiltration ponds and monitoring bores
Organics Pesticides, MBAS, TOC and DOC
2 Infiltration ponds and monitoring bores
Field determinations pH, turbidity, temperature, dissolved oxygen, ORP
52 Infiltration ponds and monitoring bores
Oxygen demand BOD, COD 12 Infiltration ponds and monitoring bores
Bacteriological indicators
Coliforms and E. coli 12 Infiltration ponds and monitoring bores
Pathogen indicators C. perfringens, viruses 4 Infiltration ponds and monitoring bores
Nutrients Total and dissolved P, Total N, TKN, NOx
4 Infiltration ponds and monitoring bores
Use of sophisticated analysis systems such as polymerase chain reaction should be
used to monitor for viruses of human concern, particularly coliphage variants.
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Table 21: Groundwater Monitoring during SAT and Horticulture Operation Parameter Suggested Determinants Frequency of testing
per year Site(s)
Heavy Metals Al, As, B, Cu, Cd, Cr, Zn (as minimum suite)
2 Monitoring bores
Dominant ions Ca, Na, K, Cl, SO4, HCO3.
4 Infiltration ponds and monitoring bores
TDS Conductance (25°C). Calculation based on above.
12 Infiltration ponds and monitoring bores
Organics Pesticides, MBAS, TOC and DOC
1 Infiltration ponds and monitoring bores
Field determinations pH, turbidity, temperature, dissolved oxygen, ORP
12 Infiltration ponds and monitoring bores
Oxygen demand BOD, COD 12 Infiltration ponds and monitoring bores
Bacteriological indicators
Coliforms and E. coli 12 Infiltration ponds and monitoring bores
Pathogen indicators C. perfringens, viruses 2 Infiltration ponds and monitoring bores
Nutrients Total and dissolved P, Total N, TKN, NOx
2 Infiltration ponds and monitoring bores
A number of water bores already exist on the AZRI site (Figure 27). These could be incorporated into the monitoring
programme, if appropriately placed to collect infiltrated water. This would require further investigation.
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Figure 27: Location of Existing Bores on AZRI.
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Quality and Quantity of Recycled Water Received from the Pipeline The quality of recycled water from the Alice Springs sewage treatment plant will be considerably better than that which is presently distributed to Blatherskite Park. A Dissolved Air Flotation (DAF) system is proposed to be installed after the final aerobic lagoon and will be used to 'polish' wastewater. This is achieved by injecting fine bubbles that attach to particles (such as the algal material present in the final lagoon) and floating them to the surface of a vessel where they can be removed. By this means, much of the algal material (and associated nutrients, organic matter etc.) in the final wastewater lagoon will be removed prior to transport to the SAT site. Inevitably some algal regrowth will occur in the infiltration basins but is not expected to reach the density of that in the final wastewater as it now exists. The DAF plant will be designed to allow future addition of extra wastewater treatment options, such as filtration
systems, should the quality of recycled water entering the pipeline be insufficient for SAT. This may occur if, for example, the quantity of algal material entering the SAT basins is such that it increases basin floor clogging rates and decreases infiltration rates. The quantity of recycled water received from the recycled water transfer pipeline will be controlled by an automatic water delivery system, similar to that used in field trials (Knapton et al., 2004a), such as SCADA telemetry, magnetic flow meters and actuated flow valve components. Under this system, measurements of flow and basin water level are recorded every 10 minutes (Plate 5). The system will include a manual over-ride capacity, to allow delivery of recycled water to be stopped in the event that quality does not meet criteria for SAT (e.g. algal content too high) or during flood events.
Plate 5: Example of Recycled Water Flow Monitoring and Delivery Equipment
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Changes in Water Quality due to SAT Jeuken (2004), in his work on the interaction of groundwater underlying wastewater in the Alice Springs region, found that bacterial indicators and viruses in the vicinity of the sewage lagoons were reduced by orders of magnitude by the soil filtration process. Given the DAF treatment to be employed prior to the SAT system, it is likely that the incoming recycled water entering the infiltration basins will contain considerably less organisms than those in the final lagoon wastewater. It is therefore unlikely that pathogenic organisms will compromise the water quality retrieved from the SAT bores in terms of its proposed use for irrigation. The precipitation of algal material in the bed of the SAT infiltration basins will render the sediment/water interface anoxic. This will assist the organic chelation of metals present in the incoming recycled water and also provide reducing conditions in these surficial sediments. These reducing conditions will immobilise metals by converting them to their sulfidic forms. Combined with the interaction of clays and other particles in the soil profile, this will effectively prevent the ingress of significant amounts of soluble metals to the storage aquifer. The DAF plant will effectively remove much of the nutrient material bound up in algal cells. In consequence only the soluble fraction present in the final lagoon wastewater will be present in the recycled water supplied to the SAT infiltration basins. The soluble fraction varies considerably depending on seasonal conditions, but is frequently less than 5% of the total nutrient fraction in final lagoon wastewater (K. Boland, unpublished data). Additional nitrification will undoubtedly occur in the infiltration basin and further reduce the nitrogen fraction by converting a portion of it into nitrogen gas which will escape from the fluid fraction. Much of the phosphorus will be bound in the sediment material precipitating onto the bed of the basins and be relatively immobile or 'fixed'
by sorption to clay particles in the soil profile. It is probable that some of the residual nitrogen will enter the SAT aquifer similar to that found by Jeuken (2004) in groundwater near the present sewage lagoons. Some species of nitrogen in groundwater (notably nitrite) are undesirable in drinking water, being associated with methylglobanaemia in infants. Given that the SAT water will be used for irrigation purposes this is unlikely to be a significant issue. Observation bores will be constructed around the basins (i.e. up, down and across gradient to enable assessment of changes in groundwater level and quality as a result of the recharge operation as well as natural variation of groundwater flowing into the project site. A sampling and analysis programme for a suite of contaminants including major ions, metals and nutrients will commence before infiltration commences to measure ambient concentrations in the adjacent monitoring bores. There is the potential that mobilisation of salts will occur as a first-flush effect and that if peak concentrations exceed those of ambient groundwater they will soon decline. There is however negligible overall risk for the environmental values of the aquifer to be adversely impacted.
Suitability of Groundwater for Non-Drinking Water Reuse The uncorrected pH of recycled water is expected to be around pH 8. The change to pH within the SAT system has not been determined, but water pH may be reduced slightly as the receiving soils are tending neutral to slightly acid, but for the purposes of this exercise no change is assumed. Gypsum or sulfur is the most common product used to counter acidic irrigation water, or soils. Gypsum is expected to be used as part of soil management and if injected during application some attenuation of alkaline waters could be expected.
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Analysis for soil boron values do not appear to have been included within the current soil analyses. It is common for boron to be in recycled water and there is commonly adequate levels to overcome soil deficiencies. Boron is relatively mobile and may be expected to appear in water extracted for irrigation, if present in the original recycled water. However, some caution is warranted, as boron can be toxic to sensitive plants (e.g. citrus) at 1 mg/L in applied irrigation water. Operational procedures should aim to maximise the amount of water being recharged while optimizing recycled water quality in the SAT by maintaining long contact times with the soil matrix. To enhance nitrogen removal, maintenance of a vadose zone is necessary to allow for partial nitrification of ammonium ions adsorbed in the vadose zone. The expected water quality of the water extracted from the SAT scheme and used for irrigation is likely to be around 1,000 to 1,200 mg/L TDS. The proposed horticultural use of primarily grapevines is consistent with the expected resultant irrigation water quality.
Quality of Recycled Water from the Alice Springs Waste Stabilisation Ponds It must be stressed that the most effective safeguard to the viability of the SAT project is effective capacity building within agencies vested with its management responsibilities. This should involve structured communications between project managers, laboratory staff and operational personnel to provide early warning of potential risks and hazards. A clear and concise operational manual will be essential and should be reviewed at least annually. Several contingent issues will need to be addressed. Plans will be required to undertake the interception of unsuitable recycled water before it reaches the SAT infiltration basins. Emergency protocols may include the following.
• Unsuitable recycled water discovered at the sewage plant proper or in the collection system may be managed subject to several decision options. Relevant issues include: o Can this recycled water be
diverted for storage prior to entering the treatment lagoons or at some stage through the lagoon system?
o Is this recycled water suitable for recirculation in the lagoon system itself? If so, what mechanisms exist to achieve sufficient recirculation capacity?
o If the recycled water is unsuitable for recirculation, can it be diverted to an evaporation/storage basin and be isolated for alternative disposal as a toxic waste?
o Is additional treatment appropriate for this stored material (e.g. lime treatment, filtration, manual disinfection etc.)?
In a worst case scenario unsuitable recycled water might reach the SAT basins proper. In such circumstances, the outflow set-up should be constructed so as to switch off further flow and use of retrieval methods using pumps and truck transport may be the only alternative, with subsequent storage and management decisions similar to those above.
Disposal of Excess Recycled Water In the event that more recycled water is generated at the WSP than can be directed to the SAT site, a number of options are available: • Use of the existing evaporation ponds
– these will remain at the WTP and will be used as required;
• Use of the surge sub-basins – these can be used to infiltrate excess recycled water;
• Irrigation at Blatherskite Park, but with improved irrigation systems and using
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tertiary treated recycled water (i.e. DAF and chlorination); and
• Direct use of tertiary treated recycled water along the pipeline route – this option would require detailed analysis should it be required or interest expressed in use of the recycled water.
Management of Basin Clogging Local soil management will need to be determined during operation, with organic mat removal expected to be the most frequent practice, with other methods to be determined depending on changes in soil characteristics. The infiltration basins can be managed to avoid nuisance conditions such as algae growth and insect breeding in the percolation ponds. Algae can clog the bottom of basins and reduce infiltration rates. Algae further aggravate soil clogging by removing carbon dioxide, which raises the pH, causing precipitation of calcium carbonate. Reducing the detention time of the recycled water within the basins minimizes algal growth, particularly during summer periods where solar intensity and temperature increase algal growth rates. The levels of nutrients necessary to stimulate algal growth are too low for practical consideration of nutrient removal as a method to control algae.
Some soil tillage following the drying cycle can help alleviate clogging potential, although scraping or ‘shaving’ the bottom to remove the clogging layer is more effective than discing. All of the above operational soil management criteria will need to be determined during the initial operations, and modified as required to ensure continued satisfactory infiltration rates.
Management of Flood Events Over the longer term, the Todd River bed has moved, and this is recorded in the geological and soils structural data for the area. It is possible this will re-occur in the future. Such a relocation of the main river bed could impact the site, but the expectation is that this is unlikely to occur in the foreseeable future, and it is not possible to place time or probability values on such an event. Recorded data indicate four very significant major flood periods over the past 50 years in the Alice Springs area. These events caused flooding in the township areas. The proposed scheme area was not flooded during these periods. Figure 28 shows the 1 in 50 year flood levels. While creeks upstream of the site do flow under some circumstances, there is a high degree of internal drainage in the middle area and waters from these creeks do not reach the proposed site. The risk of floods occurring on the site is unlikely.
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Figure 28: Land Liable to Flooding. (Source: DIPE, 1999)
Summary of Potential Impacts and Safeguards A summary of potential impacts and proposed safeguards and contingency measures are summarised in Table 22. To determine the significance of impacts that may occur, Australian Standard 4360 (1999) Risk Management was used (Appendix 4). Using this standard, each
potential impact is assessed in terms of the likelihood of occurrence and the consequence of occurrence. The product of these two scores gives an overall risk rating, providing guidance on the significance of the management strategies required.
AZRI
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Table 22: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Soil Aquifer Treatment.Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Inadequate basininfiltration
Operation Low Conservative basin designUse of 7 day wet/dry cyclesAnnual maintenance to scarify basinfloor and remove sediment and organicmaterial build up
Automatic monitoring ofwater levels in ponds andrecycled water inflow ratesto maintain water levels
Modify wetting and drying cycleIncrease frequency of basinfloor maintenanceIncrease tertiary treatment trainto provide further polishing (e.g.filtration)
Localised surfaceseepage orponding outsidebasin
Operation Low Use of low permeability bundconstruction material
Weekly inspections ofinfiltration basins
Installation of local cut-offbarriers or shallow groundwaterspears to intercept preferentialflow pathways
Widespreadsurface seepageor pondingoutside basin
Operation Medium Investigations of groundwaterconditions, infiltration tests andgroundwater flow modelingExperience with similar palaeochannelconditions in Alice Springs
Installation of extensivegroundwater monitoringnetwork targeting thepalaeochannel and themore shallow permeablelayers radiating outwardfrom the SAT basins to theAZRI site boundaries
Install infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannel or extractgroundwater and inject intoShannon formationDecrease volume of recycledwater disposed of through SATCease SAT operations
SAT
Increase in longterm, widespreadgroundwaterlevels standingwithin <10 m ofthe surface
Operation High Investigations of groundwaterconditions, infiltration tests andgroundwater flow modeling provideconfidenceGroundwater of suitable depth to avoidmounding impacts on soils andvegetationExperience with similar palaeochannelconditions in Alice Springs
Installation of extensivegroundwater monitoringnetwork targeting thepalaeochannel and themore shallow permeablelayers radiating outwardfrom the SAT Basins to theAZRI site boundaries
Install infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannel or extractgroundwater and inject intoShannon formationDecrease volume of recycledwater disposed of through SATCease SAT operations
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Significant lateralmovement ofgroundwateroutsidepalaeochannel
Operation High Investigations of groundwaterconditions, infiltration tests andgroundwater flow modeling provideconfidenceExperience with similar palaeochannelconditions in Alice Springs
Installation of extensivegroundwater monitoringnetwork targeting thepalaeochannel and themore shallow permeablelayers radiating outwardfrom the SAT Basins to theAZRI site boundaries
Do nothing where water qualityor depth below ground surfaceis not considered an issueInstall infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannel or extractgroundwater and inject intoShannon formationCease SAT operationsPump out of basins and removeoff-site poor quality recycledwater
Groundwatermigration to otheraquifer systems
Operation Medium Investigations of groundwaterconditions, infiltration tests andgroundwater flow modeling provideconfidenceExperience with similar palaeochannelconditions in Alice Springs
Routine monitoring ofexisting network ofmonitoring and operationalextraction bores forpotential changes
Do nothing where water qualityis not considered an issueCease SAT operations
SATcontinued
Preferential flowof lower qualitygroundwater fromquaternarysystems tounderlyingTertiary Systemsalong existingbore networks
Operation Medium Routine monitoring of water quality Routine monitoring of waterquality
Do nothing where water qualityis not considered an issueReplace or repair bore networksCease SAT operations
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
SATcontinued
Recycled watervolume in excessof infiltrationcapacity
Operation Low Divert recycled water to existingevaporation pondsDirect use at Blatherskite Park andTree Lot, but with improved irrigationefficiency and design
Minimalinfiltration ormixing ofrecycled waterintopalaeochannel(i.e. poor orirregular waterquality)
Extraction forhorticulture
Low Investigations of groundwaterconditions, infiltration tests andgroundwater flow modelingExperience with similar palaeochannelconditions in Alice Springs
Routine monitoring of waterfrom extraction bores
Install infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannelInvestigate and redesignextraction bore networkCease extraction operations
Variable reusewater quality
Irrigation Medium Irrigation water expected to be ofhigher quality than existinggroundwaterUse of tertiary treatment train toprovide (e.g. Dissolved Air Flotation)Augmentation of irrigation water toreduce pH, e.g. gypsum or sulfur
Routine monitoring of waterfrom extraction bores
Use of holding tanks to mix thevarious extraction bore watersourcesIncrease tertiary treatment trainto provide further polishing (e.g.filtration)If continued use unacceptable,revert to current irrigationprogramme and use ofevaporation ponds in interim.
Horticulture
Guarantee ofsupply ofirrigation water
Irrigation Low Basin design incorporates minimuminfiltration rates required for extractionof required volume of water
Monitor volume of recycledwater entering basins
Adjust volume as requiredReduce horticultural activities
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Overtopping ofTodd River atAZRI site
Rainfall/floodevents
Low Erosion control methods in place withinhorticulture siteEarly warning alert in place to providetime to shut down recycled watertransfer pipe
None required Do nothing – freshwater will notaffect water quality
External Factors
Overtopping ofSAT Basins
SATConstruction
Low Construction of walls of SAT basins towithstand 100% increase in volume ofwater containedEarly warning alert in place to providetime to shut down recycled watertransfer pipeBasin design includes surge sub-basins
Automatic monitoring ofwater levels in ponds
Cease transfer of recycledwaterUndertake erosion remediationas required
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Further Investigation and Assessment Additional groundwater discharge investigations are required to the south east, in the northern part of the Airport block. A sampling and analysis programme for a suite of contaminants including major ions, metals and nutrients should commence before infiltration commences to measure ambient concentrations in the nearest bores. Further investigation is required to determine the nature, extent and location of
the palaeochannel beyond the AZRI site to ensure that impacts upon other groundwater resources and downstream surface water features will not occur or impact on any future beneficial use down gradient from the AZRI site. A network of groundwater monitoring bores will need to be installed to confirm the conceptual model, monitor water levels and water quality changes over time, to assess effectiveness of the SAT scheme and to ensure timely identification and therefore rectification of any operational variances.
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WASTE MANAGEMENT Waste Products of SAT Scheme The use of a pre-treatment system on the wastewater before delivery to the SAT area is designed to minimise the presence of excess organic matter and algal particulates, although some may form on site during the infiltration phase, particularly in summer when temperatures and sunlight levels are higher. The filtrate mats that form on the infiltration basin floors is a ‘waste’ by-product associated with SAT. Several options are available for management of this material. It could be considered as a waste product and disposed of to landfill, and this may be a preferred option initially. However, the material is of value as a source of organic material to the local soils and interaction with local facilities already handling organic wastes for composting could allow development of windrow composting adjacent to the infiltration basins, or it may be possible to utilise the existing composting operations already operational in Alice Springs, located at the landfill site adjacent to the wastewater ponds, and dispose of the material via composting there. This waste material is often suitable for reuse as a biosolid. In the absence of undesirable contaminants, such as heavy metals or toxic organic residues, this can be used as a soil conditioner to improve the soil structure and fertility of irrigated soils. Such use of this material will be subject to confirmation of its suitability in terms of contaminant concentration. This will require analysis of the by-product for a range of relevant determinants. Nonetheless, the absence of concentrated manufacturing industry in Alice Springs (e.g. large scale tanning, electroplating and chemical plants etc.) implies that the material present in these filtrate mats will not contain unacceptably high concentrations of such undesirable components. The material will be
dominated by the precipitated algal material originating from the wastewater sourced from the aerobic final lagoons at the WTP. As such, it will be comprised mainly of organic material with elevated concentrations of phosphorus, nitrogen and trace elements – not unlike commercially available fertilizers and soil conditioners. In order to render this material suitable for use as a fertilizer/soil conditioner it will need to be dried to eliminate potential pathogens (e.g. Cyclospora) that might have extended viability under moist conditions (Gerba et al., 2003). This could be achieved by simply spreading the material adjacent to the SAT site (i.e. within its immediate catchment) and sun-drying it for a period sufficient to both evaporate moisture and provide extended exposure to ultra-violent solar radiation thereby effectively 'sterilising' the filtrate material. Subsequent to this the treated biosolid will likely be suitable for agricultural purposes although (depending on appropriate testing) it may not be appropriate for crops used for raw consumption (Hillman et al., 2003). Rusin et al. (2003) in a study of the occurrence of the pathogen Staphylococcus aureus found that it was not present in treated biosolids. Odour problems are expected with biosolids and similar by-products, commonly because they rapidly turn anaerobic when stored in a pile and management to minimise these issues will be required. Spreading of the drying pile into a thin layer assists in preventing the material from becoming anaerobic, mixing with coarse particulates, such as woodchips or green waste and agitation are methods of managing odour issues. There will also be organic wastes generated in the wastewater pre-treatment phase at the DAF plant and disposal of these to landfill after drying is the common
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option. However, the management of wastes from the DAF plant is outside of the scope of this PER.
Waste Products of Horticulture Scheme All organic material waste from the fruit packing system will be composted on site and re-incorporated with the soil under the irrigated plants. Water from the fruit packing system will be collected in a sump pit and used on site as an organic soil amendment. Paper and cardboard packaging will be recycled. Agrochemical and similar containers will be recycled through agrochemical drum recycling programs. Plant prunings will be mulched in situ and returned to the soil. Grape waste (rejected berries and bunches) will be composted, as will citrus waste (rejected oranges, rind and pith from juice processes), melon waste (rejected melons) and asparagus waste (off-cuts) should these be grown. Plastics will be used in the packaging process and also on grapevines to protect grape bunches. There is a risk that these may be blown about the horticultural site, becoming litter. It is recommended that routine site inspections are undertaken to ensure that any plastic bags that detach from the plants/fruits are routinely collected. Waste plastics will need to be disposed of with general refuse. Cardboard and paper products will also be used during the horticultural processes. These will be recycled wherever possible and wastes composted for use on site.
The fruit packing system requires use of drinking water for cleaning the product. This water will be collected in a purpose built sump and it is proposed that the water will be collected. The water will need to be tested for quality, as part of routine water quality monitoring, and if it is found to be of a suitable quality (similar to the quality of water used for irrigation), will be reused on site. If it is not of a suitable quality, it will require disposal through an approved liquid waste disposal contractor. A range of agrochemical containers will require disposal. There is a DrumMuster receiving yard at the Alice Springs landfill, but it has been non-operational for over 12 months. However, there are plans to have this programme operational in the future and it would be a useful facility for disposal of agrochemical containers. In the interim, a licensed contractor would need to be used for disposal of these containers.
Summary of Potential Impacts and Safeguards A summary of potential impacts and proposed safeguards and contingency measures are summarised in Table 23. To determine the significance of impacts that may occur, Australian Standard 4360 (1999) Risk Management was used (Appendix 4). Using this standard, each potential impact is assessed in terms of the likelihood of occurrence and the consequence of occurrence. The product of these two scores gives an overall risk rating, providing guidance on the significance of the management strategies required.
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Table 23: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Wastes.Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
SAT Disposal ofaccumulatedalgal materials onbasin floor
Operation Medium Possible use as biosolidfertilizer/soil conditionerIf testing shows unacceptablelevels of pathogens, treat withUV (sunlight) or mix with greenwastes and compost (heat killspathogens and compostingeliminates odour)
Testing of material to determineconcentrations of microbialorganisms, chemicals andmetals
Disposal to licensed site, withappropriate approvals
Disposal of greenwastes, prunings,crop waste
Operation Low Compost on siteUse to augment soils inhorticulture area
None required Disposal to appropriate licensedgreen waste facility, withapprovals if required
Disposal of waterfrom packingsystem
Operation Low Collect in sump pitUse on site for soilaugmentation
Routine monitoring of waterquality prior to application onsite
Disposal through wastedisposal contractor
Disposal ofplastics
Operation Low Reuse where possibleWhere reuse is not an option,dispose of with other refuseEnsure does not become litteron horticultural site
Routine inspection of area andcollection of plastic blown fromplants
Disposal through wastedisposal contractor
Disposal ofcardboard andpaper
Operation Low Recycle None required Disposal to appropriate wastefacility
Horticulture
Disposal ofagrochemical andsimilar containers
Operation Low Recycle None required Disposal to appropriate wastefacility
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Further Investigation and Assessment Investigate the possibility of using the DrumMuster programme for disposal of agrochemical containers, or at least ascertain when it may be likely to commence operation in Alice Springs. If the programme is not to be initiated, investigation into a suitable disposal facility will be required.
Determine whether the organic wastes produced on the SAT basin floors are to be considered a biosolid, given biosolids are generally from sewage with fewer treatment trains. If it is to be classed as a biosolid, approvals will be required for its disposal. If it is not classed as a biosolid, it may be used as described above.
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BIODIVERSITY Existing Environment The AZRI site has been used for agricultural purposes since it was established in the 1950s. In this time it has been subjected to intensive grazing from livestock, including being the location for the Sentinel Herd trial for 30 years. There has also been an active programme of pasture grass planting during this time. Therefore, although the following sections refer to vegetation units and plants species which may occur on the site, it should be considered in the context of a highly disturbed site and much of the vegetation remaining on the site is structurally and floristically degraded. This degradation also has implications for the quality of habitat on the site and therefore many of the fauna species which could be expected to occur in intact vegetation units, may not be present on the AZRI site.
Vegetation Detailed vegetation surveys for the AZRI site are unavailable, but a number of other studies have been undertaken in adjacent land, which provide a reasonable indication of the representative vegetation communities likely to be located on the AZRI site. These include vegetation assessments within the Desert Knowledge Precinct (adjacent to the AZRI site) and the Alice Springs Airport (opposite the AZRI site on Colonel Rose Drive). These surveys also provide a useful guide for re-establishment of plant communities within the proposed buffer zones of the horticultural scheme. The Desert Knowledge Precinct covers 30 ha, partly overlapping the north-eastern corner of the AZRI site. A flora survey in the Precinct identified two main vegetation types - ‘Large Sandy Red Gum Creeklines’ and ‘Ironwood and Fork-leaved Corkwood on Alluvial Flats’ (Barnetson and Richardson, 2002). Beneath the larger vegetation, the introduced Buffel Grass
(Cenchrus ciliaris) and the noxious weed commonly known as Prickly pear (Opuntia stricta var. stricta) were recorded. The survey also described the endemic vegetation to consist of 12 species of trees and shrubs and listed their respective size and abundance (Barnetson and Richardson, 2002). A more recent vegetation survey, undertaken at the Alice Springs Airport, identified six vegetation types, described below (Paltridge and Latz, 2003): • Witchetty Bush and Ironwood on
sandy-loam rises – Ironwoods (Acacia estrophiolata) are the dominant species in the tree layer, but Mulga (A. aneura) may also be present. The shrub layer is dominated by stands of Witchetty Bush (Acacia kempeana)shrubs with a scattering of A. murrayana, Hakea divaricata and Senna artemisioides subsp. filifolia.Buffel Grass (Cenchrus ciliaris) is the most common understorey plant, but other common ground layer species include Aristida contorta, A. holathera,Eragrostis eriopoda, Eriachne helmsii,Sclerolaena convexula, Tribulus eichlerianus and Tripogon loliiformis;
• Witchetty Bush and Whitewood on sandy rises – this community had a dominance of Whitewoods (Atalaya hemiglauca) in the tree layer;
• Mulga in valleys with red earth soils – similar to Witchetty Bush and Ironwood, but with a greater density of Mulga (Acacia aneura), with a scattering of Ironwoods (A. estrophiolata). The shrub layer comprises mainly Acacia kempeana and Rhagodia eremaea. The dominant understorey species are Cenchrus ciliaris and Digitaria brownii;other ground layer species include Aristida contorta, Cheilanthes lasiophylla, C. sieberi subsp. sieberi, Eragrostis eriopoda, Fimbristylis dichotoma, Ptilotus polystachyus, Rhodanthe charsleyae, Sclerolaena
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convexula, Tribulus eichlerianus and Tripogon loliiformis;
• Ironwood and Fork-leafed Corkwood woodland on alluvial flats – this vegetation type has two variants, based on the proportion of the dominant tree species of Ironwood (Acacia estrophiolata) and Fork-leafed Corkwood (Hakea divaricata) and other less common species, such as Atalaya hemiglauca, Corymbia aparrerinja, Eucalyptus camaldulensis var. obtusa, E. coolabah subsp. arida.Acacia murrayana is the dominant shrub species but A. victoriae and Senna artemisioides subsp. filifolia also occur. Cenchrus ciliaris and Enneapogon avenaceus are the most common species in the ground layer which also includes Atriplex elachophylla, Calotis hispidula, Maireana scleroptera, Portulaca oleracea, Salsola tragus, Sclerolaena convexula, S. costata, Tribulus eichlerianus, and Tripogon loliiformis.This is the most widely distributed vegetation type within the Alice Springs municipality (18 %), and it also extends through other parts of the MacDonnell Ranges and Burt Plain bioregions; and
• Drainage depressions with Coolibah and Ironwood - Ironwood (Acacia estrophiolata) is the dominant overstorey species, but may also include Coolibahs (Eucalyptus coolabah) and Whitewoods (Atalaya hemiglauca) in intact stands. The shrub layer is diverse and includes Acacia victoriae subsp. arida, A. murrayana, Capparis spinosa var.nummularia, Eremophila longifolia, Einadia nutans subsp. nutans. Grevillea striata, Hakea divaricata, Jasminum didymum, Pittosporum angustifolium and Senna artemisioides subsp. filifolia. Perennial grasses are a characteristic feature of this vegetation community. ground layer is dominated by Cenchrus ciliaris and Eulalia aurea and also includes Chrysopogon fallax, Dichanthium sericeum var. sericeum, Enteropogon ramosus, Glycine canescens,
Haloragis aspera, Malvastrum americanum, Rutidosis helichysoides and Themeda avenacea.
The Coolibah and Ironwood communities at Alice Springs Airport were further described and mapped to determine habitat value (Smith and Firth, 2004). Of the vegetation communities described by (Paltridge and Latz, 2003), the AZRI site contains remnants of: • Witchetty Bush and Ironwood on
sandy-loam rises, located north of the proposed horticultural area;
• Ironwood and Fork-leafed Corkwood woodland on alluvial flats, the dominant plant community within the area proposed for the SAT basins and horticultural programme; and
• Drainage depressions with Coolibah and Ironwood, located in patches along the drainage line east of the horticultural area. This vegetation type is considered a rare habitat by Paltridge and Latz (2003).
A total of 181 plant species were recorded at Alice Springs Airport (Paltridge and Latz, 2003). However, it is highly unlikely that the AZRI site contains a similar plant species list, because of the history of site disturbance through grazing and other agricultural activities. Buffel Grass is a dominant understorey plant species across the AZRI site.
Significant Flora The status of conservation significant flora species is unknown in the proposed SAT and horticultural sites. The NT Parks and Wildlife Fauna Database does not include any endemic species on the site (Appendix 6). Flora surveys in the Desert Knowledge Precinct (Barnetson and Richardson, 2002) and at the Alice Springs Airport did not locate any species listed under the Environment Protection and Biodiversity Conservation Act (Paltridge and Latz, 2003; Smith and Firth, 2004). A search of the EPBC database revealed the
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possibility that the annual herb Minuria tridens could occur at the AZRI site. This species is classified as Vulnerable, which means that it is a taxon facing a high risk of extinction in the wild in the medium-term future. This species is also listed as Vulnerable under the Territory Parks and Wildlife Conservation Act.
Another three species listed under the Territory Parks and Wildlife Conservation Act were located on Alice Springs Airport (Paltridge and Latz, 2003): • Einadia nutans subspecies nutans –
classified as Near Threatened (taxa that risk becoming Vulnerable in the wild). This species has a perennial habit and is typically located in heavy soils along water courses or in fire protected areas and was located in Mulga communities, at Alice Springs Airport;
• Ixiochlamys nana – classified as Data Deficient (taxa suspected of being Rare, Vulnerable or Endangered, but whose true status cannot be determined without more information). This species is an annual herb that occurs on clay loam plains and was located within the Ironwood and Fork-leafed Corkwood woodland communities at Alice Springs Airport; and
• Maireana lobiflora – classified as Data Deficient. This species is a type of saltbush and generally occur on heavy soils.
Weed Species The NT Parks and Wildlife Fauna Database provides records of 35 species of naturalised plants, consisting of forbs, grasses and sedges and not including Buffel Grass, which is widespread across the site.
Fauna As with the vegetation, no fauna surveys have been conducted specifically within the
AZRI site. A fauna survey carried out in the Desert Knowledge Precinct did not result in the positive identification of any ground dwelling fauna (Cole and Pavey, 2003). A search of the NT Parks and Wildlife Fauna Database provided records for 54 bird, seven mammal and 17 reptile species (refer to Appendix 6), based on records between 1964 and 2001. Barnetson and Richardson (2002) recorded 30 bird species, with the expectation that a further 13 species could occur in the area. The survey report noted that a high percentage of the bird species require tree hollows in which to nest (Barnetson and Richardson, 2002). A survey of fauna at the Alice Springs Airport recorded 46 bird species, most of which are common and abundant throughout most central Australian habitats (Paltridge and Latz, 2003). Twenty species of reptile have previously been recorded at the Alice Springs Airport (Smith and Firth, 2004), all of which are common and widespread through the region. The fauna survey of Paltridge and Latz (2003) recorded five native species of mammal, including the Dingo, whereas the survey of Smith and Firth (2004) recorded one native species of mammal. The low diversity of mammals trapped or sighted was attributed to seasonal factors. None of the fauna surveys conducted included an assessment of bats, but they are known to occur River Red Gums and other hollow-bearing trees at AZRI and other locations nearby. It is expected that approximately 11 species of bat may occur in the area, of which all but two are hollow-roosting species (C. Pavey, pers. comm.).
Significant Fauna No birds of national conservation significance were recorded at the Airport or within a three kilometre radius, but three species have been recorded that are classified as Near Threatened under the Territory Parks and Wildlife Conservation
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Act (Paltridge and Latz, 2003; Smith and Firth, 2004, NT Parks and Wildlife Fauna Database, 2004): • Red-tailed Black Cockatoo
(Calyptorhynchus banksii); • Grey Falcon (Falco hypoleucos); and • Square-tailed Kite (Lophoictinia isura). The NT Parks and Wildlife Fauna Database records the Australian Bustard (Ardeotis australis), which is classified as Vulnerable, as occurring in the area in 1986. Migratory birds which may occur in the vicinity of the AZRI site includes the Rainbow Bee-eater (Merops ornatus), which is included on the Japan and Australia Migratory Birds Agreement (JAMBA), which afford protections to migratory birds and their habitats. The EPBC database includes a further two migratory bird species which may occur in the region, but which have not previously been recorded at the Airport: • Oriental Plover, Oriental Dotterel
(Charadrius veredus); and • Oriental Pratincole (Glareola
maldivarum). The NT Parks and Wildlife Fauna Database records two species of reptiles classified as Data Deficient, the King Brown Snake (Pseudechis australis) and the Western Brown Snake (Pseudonaja nuchalis), as having been recorded in the region. Paltridge and Latz (2003) refer to the Endangered Slater’s Skink (Egernia slateri slateri) as likely to have been present at the Airport until about 1970 and note that it has previously been recorded within 2 kms of the site, which would include the AZRI land. However, this population appears to have suffered local extinction following the invasion of Buffel grass, and it is considered unlikely to currently occur at Alice Springs Airport (Barnetson and Richardson, 2002; Paltridge and Latz, 2003). The EPBC database also lists the Vulnerable Great Desert Skink (Egernia kintorei) as potentially occurring in the region, but this species is a desert dune
dwelling animal and highly unlikely to occur at AZRI. The Kultarr (Antechinomys laniger) is classified as Near Threatened under the Territory Parks and Wildlife Conservation Act. This species of mammal has previously been recorded in the region in 1960 and 1965 and more recently in 2000, when a dead specimen was found on Colonel Rose Drive (M. Barnes, pers. comm., 2004). It has not been located in recent fauna surveys at the Airport (Paltridge and Latz, 2003; Smith and Firth, 2004). The EPBC database lists an additional five species of native mammal which may occur in the region: • The Southern Marsupial Mole
(Notoryctes typhlops) – classified as Endangered;
• The Central Rock-rat (Zyzomys pedunculatus) – classified as Endangered;
• The Black-footed Rock-wallaby (Petrogale lateralis) – classified as Vulnerable;
• The Mulgara (Dasycerus cristucauda)– classified as Vulnerable; and
• The Greater Bilby (Macrotis lagotis) -classified as Vulnerable.
It is highly unlikely that any of these species will be located at AZRI, as they have not been recorded in the Alice Springs area for many years and could be considered to be locally extinct.
Fauna Habitat There are elements within the proposed horticultural site which provide fauna habitat, particularly for bats and birds. Coolibah and Ironwood patches may provide breeding hollows for a range of bird species at different times of the year. Generally, the older the tree, the more hollows that may be present. The River Red Gum is a particularly important species for bird nests as well as for roosting bats.
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Isolated River Red Gums occur along the southern and northern boundaries of the proposed horticultural area. The Endangered Slater’s Skink prefers heavy loamy soils on alluvial plains, where it excavates multi-entrance burrows beneath low vegetation. Its main period of activity is at night as well as at dusk and dawn. The remaining low vegetation at the proposed horticultural site is variable and in some areas it is in very good condition and in other areas it is quite degraded. The proposed horticultural area includes lighter sandy loams, loams, clay loams and sandy clay loams and so it is a possibility that the site could contain suitable habitat. The Near Threatened Kultarr prefers grasslands and low shrublands on desert plains and stony and sandy country. It has been found sheltering in logs and stumps, between saltbush and spinifex tussocks and in deep cracks in the soil. It is unlikely that the proposed horticultural area contains suitable habitat. However, with the recent (2000) discovery of a dead Kultarr on Colonel Rose Drive, this possibility can not be completely discounted.
Pest Species A range of feral animals have previously been recorded at the Alice Springs Airport (Paltridge and Latz, 2003; Smith and Firth, 2004). These include the Feral Camel (Camelus dromedaries), the Feral Cat (Felis catus), the European Rabbit (Oryctolagus cuniculus) and the House Mouse (Mus domesticus). It is likely that each of these, except the Feral Camel, will also occur on the AZRI site.
Potential Impacts The proposed SAT and horticultural schemes may impact on the natural values of the AZRI site as a result of: • Clearing of native vegetation for
preparation for the SAT basins and associated infrastructure and clearing
for crop planting and infrastructure establishment;
• Loss or alteration of habitat through vegetation clearance or changes to groundwater flows and heights;
• Disturbance to fauna activity during construction and operational phases, particularly birds and mammals;
• Changes to groundwater flow in shallow sands, resulting from changes to surface flow patterns or mounding of groundwater during infiltration;
• Disturbance of soils and subsequent establishment of new weed species, or expansion of existing weed infestations;
• Nutrification of soils and subsequent enhanced growth of weed species;
• Pollution of soils through leakage or spillage of hazardous compounds (e.g. fuels, oils) or inappropriate waste management practices;
• Erosion of soils (including creation of dust) resulting from water movement, vehicular traffic or inappropriate basin construction methods;
• Direct impact on species attracted to site, such as birds attracted to infiltration basins;
• Attraction of flying insects, including mosquitoes, to the site, resulting from unseasonal presence of surface water; and
• Reduction in the amount of connectivity of bushland between the airport and the Todd River.
Off-site (positive) impacts will occur at Ilparpa Swamp, in response to the cessation of dry weather wastewater overflow. Initially, this may cause adverse impacts on fauna and flora reliant on the swamp habitat. However, over time, it is planned to rehabilitate the area to replace the 47 weeds species known to inhabit the site (Arid Lands Environment Centre, 2000) and reinstate natural vegetation communities that do not rely on constant inundation.
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Another off-site impact is the effect of the reduced area of inundation of the evaporation ponds at the WTP. It is recognised that the ponds, as one of the few permanent areas of open water in central Australia, play an important role for migratory and nomadic birds, and provide breeding sites for some species. Concern has been expressed about the impact this will have on a range of waders and shorebirds, which are the focus for local, intestate and international ornithologists visiting Alice Springs. The WSP, although containing water, do not attract as many birds as the evaporation ponds. It has been proposed by the Alice Springs Field Naturalists Club that some areas of water be left in the evaporation ponds, to cater for these birds. This matter is outside of the scope of this PER and is a matter to be discussed between Power and Water and concerned community members.
Safeguards
Targeted Surveys In order to be certain that protected flora and fauna are not inadvertently affected during vegetation clearing, it may be necessary to undertake targeted surveys for: • Significant flora species (Minuria
tridens, Einadia nutans ssp nutans,Ixiochlamys nana and Maireana lobiflora);
• Hollow-bearing mature trees, which provide habitat for bats and some bird species; and
• Slater’s Skink and the Kultarr, focussing on likely habitat areas only.
Vegetation Clearing Vegetation clearing should be undertaken in a staged approach, removing only those areas of vegetation immediately required for use. In the first year, this would mean only the area for the SAT basins and the first 20 ha of horticulture should be cleared.
This minimises the extent of the impact in a given period. Care should also be taken to ensure only the areas requiring clearing are impacted upon and all areas to be cleared must be approved by AAPA. Adjacent vegetation should be protected during the clearing process, by ensuring that operators are aware of the boundaries for proposed clearing. This can be managed simply by marking trees to be left and the boundary of areas to be cleared. Vehicles and plant should be parked in designated areas, such as existing roads and tracks, rather than in areas of vegetation. The final shape of the infiltration basins should be designed to accommodate vegetation in the immediate vicinity, specifically trees identified as being culturally significant. Vegetative matter obtained during the clearing process could be mulched on site and used to enhance the buffer areas, or applied elsewhere on the site to assist in dust control. Important habitat elements, such as hollow logs, should be moved to areas of the buffer zone requiring enhancement. This has the dual purpose of providing habitat as well as enhancing soil stability. The horticultural and SAT sites should be fenced to prevent access by grazing animals, which have the potential to further destabilise soil and impact on vegetation.
Weed Management Weed control will be undertaken at the SAT site and within the horticultural site, as required. Disturbance of soils generally leads to weed establishment, so it is highly likely that weed control will be required. At the SAT site, mechanical weed control is recommended, to avoid the risk of herbicides entering the infiltrate. The use of erosion control matting on the basin walls will have the dual purpose of
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stabilising the walls as well as reducing weed growth. At the horticultural site, weed control will be undertaken as part of best practice procedures for maximising crop productivity. It is proposed that glyphosate-based products will be used for weed control. This product breaks down on the soil surface over time and does not pose residual soil contamination risks. It is highly likely that the pasture grass, Buffel Grass, will establish in some disturbed areas. In the absence of other ground cover species to maintain soil stability, it is unlikely control of Buffel Grass will be undertaken. Instead, it should be managed, through grazing and maintenance of firebreaks, to reduce fire risk.
Fire Control The AZRI site currently has a well-maintained network of 4 m wide (minimum) firebreaks and access tracks. It is highly likely that a new firebreak will be required along the northern boundary of the proposed horticultural site, to minimise the impact of fires coming into the area from the north. Existing firebreaks within the proposed horticultural area will be retained or, if positioned in an area required for crops, new breaks established. Currently, AZRI avoids open fires on site and this practice would be maintained. All members of the workforce should be inducted into fire prevention and management and fire fighting equipment should be kept at strategic locations (e.g. at each facility/building and in vehicles). In the event that a fire does occur, AZRI staff and local fire fighters would be involved in fire fighting. It is expected that the current policy of fire prevention would be continued.
Mosquito Management The existing mosquito issues at Ilparpa Swamp are mainly the result of stagnant water and emergent vegetation. These two factors combine to provide suitable breeding areas. To manage potential mosquito issues at the SAT basins, it is proposed to ensure that the basins are free of vegetation and that each basin does not have lengthy periods of water available for mosquitoes complete their life cycle. The operational cycle of the basins will initially be seven days wetting and seven days drying alternating between the two sets of basins. Although the SAT basins do have the potential to attract mosquitoes or increase existing populations, it is anticipated that this cycle will be short enough to prevent progression from the larval to adult stage. If this is found to be inadequate, a shorter wetting and drying cycle can be utilised to prevent breeding of mosquitoes, without impacting on the effectiveness of the infiltration basins. A basin design consisting of several sub-basins affords a higher degree of flexibility in this regard. The proposed holding area for irrigation water will also need to be monitored for mosquito activity. The design of the holding area should incorporate steep sides and be free of vegetation to ensure the area is unsuitable for mosquito breeding. Consideration should be given to the use of amber external lighting or cool white lights to minimise the attractiveness to mosquitoes. However, where this may impact on Occupational Health and Safety requirements, this will not be an option. Mosquito monitoring should be undertaken at regular intervals during the year. During the summer months when mosquito activity is likely to be widespread because of rainfall and high temperatures, monitoring should be undertaken weekly. In winter months, when there is less water available and temperatures are cooler, this could be extended to monthly monitoring. Monitoring can take the form of visual checks for larvae and also use of baited
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mosquito traps, currently in use at other sites in the Northern Territory.
Feral Animal Management The main feral animal issue expected on site relates to rabbits. Rabbits will need to be managed for the horticultural project, as well as to assist in maintaining the vegetative buffers. Therefore, rabbit-proof fencing of the horticultural site will be required.
Summary of Potential Impacts and Management A summary of potential impacts and proposed safeguards and contingency measures are summarised in Table 24. To determine the significance of impacts that may occur, Australian Standard 4360 (1999) Risk Management was used (Appendix 4). Using this standard, each potential impact is assessed in terms of the likelihood of occurrence and the consequence of occurrence. The product of these two scores gives an overall risk rating, providing guidance on the significance of the management strategies required.
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Table 24: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Biodiversity.Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Loss ofvegetation
Clearing High Minimise area to be clearedRetain large/mature trees andshrubsObtain permission to clear fromAAPA and through LandClearing GuidelinesConfine earth moving vehicles,and workers vehicle to setparking areas (on existingservice roads) and tracks tominimise the potential impact onnative flora
Ensure only nominated areatargeted during clearingoperations
RevegetationModify the surface of accessroads, where expected high usecreates dust impact onvegetation
Loss of significantflora
Clearing Medium Undertake targeted survey priorto commencement of clearing
Undertake targeted survey priorto commencement of clearing
Seed collection andestablishment in suitable siteelsewhere or translocation(although this is generallydifficult to achieve). Advicewould need to be sought as towhether this is a controlledaction under the EPBC Act forsome species.
SAT
Disturbance tofauna
ClearingConstructionOperation
Medium Disturbance from machineryand equipment short term andminimalFence area holding infiltrationbasins to prevent wildlife/stockaccess
None required Dependent on issue andspecies involved, may requiremodification to basin to preventaccess
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Loss of significantfauna
Clearing Medium Undertake targeted survey priorto commencement of clearing
Undertake targeted survey priorto commencement of clearing
Translocation under the adviceof Parks and Wildlife ormaintenance of the habitatarea, depending on its location.Advice would need to be soughtas to whether this is a controlledaction under the EPBC Act forsome species.
Loss of habitat Clearing High Minimise area to be clearedRetain large/mature trees andshrubsSite of proposed activity hasdegraded habitat onlyRetain any significant habitatelements, such as, fallen logsand hollow-bearing trees orrelocated for use as artificialhabitat areas elsewhere (e.g. inbuffers)No vehicles are to enter thelocal drainage channels, suchas St Mary’s Creek
Ensure only nominated areatargeted during clearingoperations
Revegetation
SATcontinued
Weedestablishment
Operation Low Undertake mechanical orphysical control of weedsaround basinsUse of erosion control mattingshould assist in prevention ofweed establishmentImported fill must be certifiedweed free before being broughton site
Monitor weeds as part of annualbasin maintenance programme
Undertake mechanical orphysical control of weedsaround basins
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
SATcontinued
Pest species ConstructionOperation
Low Areas requiring drainage will beconstructed so that no poolingcan occur within the drainsUse of 7 day wet/dry cycles todisrupt mosquito breedingAnnual maintenance to scarifybasin floor and removesediment and organic materialbuild upUse amber external lighting oninfrastructure fitted with lights
Automatic monitoring of waterlevels in ponds and recycledwater inflow rates to maintainwater levelsMonitor effectiveness of wet/drycycle of basins and alter asrequired to disrupt mosquitobreeding cycle
Modify wet/dry cycle,accordinglyIncrease frequency of basinfloor maintenanceIncrease tertiary treatment trainto provide further polishing (e.g.filtration)
Loss ofvegetation
Clearing High Minimise area to be clearedRetain large/mature trees andshrubsObtain permission to clear fromAAPA and through LandClearing GuidelinesConfine earth moving vehicles,and workers vehicle to setparking areas (on existingservice roads) and tracks tominimise the potential impact onnative flora
Ensure only nominated areatargeted during clearingoperations
RevegetationModify surfaced of accessroads, where expected high usecreates dust impact onvegetation
Horticulture
Loss of significantflora
Clearing Medium Undertake targeted survey priorto commencement of clearing
Undertake targeted survey priorto commencement of clearing
Revegetation
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Disturbance tofauna
ClearingConstructionOperation
Medium Disturbance from machineryand equipment duringconstruction short term andminimalFence horticulture area toprevent wildlife/stock accessMaintain a clean and tidy workarea to ensure that native faunaare not attracted to the siteUse of bird fright as required,and after advertisement inmedia re schedule for use(following current practices)
None required Dependent on issue andspecies involved, may requiremodification to basin to preventaccess
Horticulturecontinued
Loss of habitat Clearing Medium Minimise area to be clearedRetain large/mature trees andshrubsRetain any significant habitatelements, such as, fallen logsand hollow-bearing trees orrelocated for use as artificialhabitat areas elsewhere (e.g. inbuffers)No vehicles are to enter thelocal drainage channels, suchas St Mary’s Creek
Ensure only nominated areatargeted during clearingoperations
Revegetation
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Weedestablishment
Operation Low Undertake mechanical, physical orchemical control of weeds, asrequiredBuffel grass should not be removedin the absence of another suitablegroundcover to stabilise soilImported soils must be certifiedweed free before being brought onsite
Monitor weeds as part ofannual basin maintenanceprogramme
Undertake mechanical, physicalor chemical control of weeds, asrequired
Horticulturecontinued
Pest species ConstructionOperation
Low Areas requiring drainage will beconstructed so that no pooling canoccur within the drainsUse amber or cool white externallighting on infrastructure fitted withlightsMaintain a clean and tidy work areato ensure scavenger birds are notattracted to the siteEnsure putrescible bins are closedand no wastes are left uncovered
None required other thannormal work sitemaintenance checks
Undertake corrective action
All Components Fire ConstructionOperation
High Continued maintenance of firebreaks at AZRIInstallation of new firebreaks, asrequired around horticulture andinfrastructure areasPrevent use of open firesPersonnel induction to minimisingfire riskHave fire fighting equipment on siteand in vehicles
Annual firebreakmaintenance programme
None available
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Further Investigation and Assessment The amount of information available on fauna and flora in the immediate vicinity of AZRI negates the need for a detailed site survey. However, prior to clearing of
vegetation, targeted surveys should be undertaken to ensure that significant flora and fauna species or their habitats are not impacted on.
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HERITAGE / CULTURAL ISSUES Existing Cultural Sites of Significance A survey of the AZRI site (Crassweller, 2004) located 10 artefact scatters that will require permission from the Minister for Environment and Heritage, through the Heritage Advisory Service, to disturb them. These artefacts were mainly located in association with a creek or drainage line and the remainder on the flat plains. The density of artefacts in the area of the proposed SAT basins was roughly 1 for every 1,000 m2 whereas the density for the remainder of the survey area was 1 for every 3,400 m2 (Crassweller, 2004). The majority of stone artefacts located during the survey were unretouched flakes manufactured from either silcrete or quartz. The two retouched flakes were manufactured from silcrete and chert and there was also one chert core that had only one platform from which the flakes were removed (Crassweller, 2004). No archaeological sites were located during the survey. However, consultation with the custodians of the land and inspection of the AAPA database has revealed that there are two Sacred Sites located in the northern part of the AZRI property and St Mary’s Creek is also considered culturally significant. All of these are outside of the nominated project area. A survey of significant trees has been undertaken (refer to Figure 5) and these trees now require permission to be cleared through AAPA. This process is ongoing.
Potential Impacts to Cultural Values There is the possibility that the identified sites of significance could be disturbed inadvertently if workforce members moved outside of the project area. The artefact scatters have been recorded in detail, have a low research potential and
have been deemed as possessing low archaeological significance (Crassweller, 2004). Despite this, the artefacts are prescribed objects under the Northern Territory Heritage Conservation Act 1991 and so permission to disturb these objects must be sought prior to any disturbance. Disturbance of the identified significant trees or other areas of significance, under Aboriginal beliefs, has a significant impact on the well-being of ancestors. Therefore, the it is very important that al procedures as laid out in the relevant legislation, are followed.
Safeguards In order to protect significant places and objects, a policy of education and prevention is the best approach. To this end, cultural awareness training is recommended for all members of the workforce, to raise awareness of the importance of these places and objects under the Aboriginal belief system. It may be necessary to fence off the Sacred Sites, but this should only be undertaken if recommended or agreed to by the Aboriginal custodians of the land. Following the appropriate regulatory processes also ensures that no trees, places or objects are disturbed without a Certificate of Authority from AAPA. Another basic measure to ensure areas are not disturbed inadvertently includes confining earth moving vehicles and workers vehicle to set parking areas (on existing service roads) and tracks to minimise the potential for these to move into inappropriate areas.
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Summary of Potential Impacts and Management A summary of potential impacts and proposed safeguards and contingency measures are summarised in Table 25. To determine the significance of impacts that may occur, Australian Standard 4360 (1999) Risk Management was used (Appendix 4). Using this standard, each
potential impact is assessed in terms of the likelihood of occurrence and the consequence of occurrence. The product of these two scores gives an overall risk rating, providing guidance on the significance of the management strategies required.
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Table 25: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Heritage and Cultural Aspects.Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Loss of ordisturbance tosignificant trees
ClearingConstructionOperation
High Obtain permission to clear fromAAPA and consultation withland custodiansConfine earth moving vehicles,and workers vehicle to setparking areas (on existingservice roads) and tracks tominimise the potential impact onsignificant trees and areasUndertake cultural awarenesstraining with workforce
Monitor clearing to ensure noinadvertent disturbance ordamage
Seek advice from AAPAAll Components
Disturbance tosignificantlandforms
ClearingConstructionOperation
Low Outside of intended project areaEnsure significant landformseasily identifiable by personnelUndertake cultural awarenesstraining with workforce
Monitor clearing to ensure noinadvertent disturbance ordamage
Seek advice from AAPA
Further Investigation and AssessmentClose consultation with AAPA and the custodians of the land will be required to ensure permission is obtained to disturb the artefacts and clear some of the treesidentified as significant.
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SOCIO-ECONOMIC ENVIRONMENT Existing Environment The AZRI and the proposed development are located in the Heavitree Local Statistical Area as defined by the Australian Bureau of Statistics (ABS). In the 2001 census the local population of this area was 2039 people with a median age of 42. The major fields of employment are in the retail and construction sector with a median weekly individual income of $400-$499. The surrounding land-uses of the AZRI include two significant landholders, the Alice Springs Airport, located to the South, and an existing residential area located to the east. The northern and western boundaries to the proposed site are buffered by vegetation and infrastructure and thus should not experience any localised impacts. There are no current proposals for future residential expansion immediately surrounding AZRI, however the potential for residential development in the long-term future can not be discounted. The Alice Springs Airport Masterplan identifies a number of future developments including horticultural and residential areas as well as commercial operations. The landowners to the east live in a residential estate that is adjacent to AZRI. Based on the Australian Bureau of Statistics (2001) data the mean household size as 2.6 persons in the Heavitree Local Statistical Area. Using this data it would be expected that approximately 280 people would reside in the whole residential area adjacent to the AZRI. The residents in this area enjoy a rural lifestyle and are likely to have concerns regarding this development due to the perceived loss of their rural residential amenity. These concerns are centred on issues of noise, odour, pesticide and fertilise use and increased vehicular traffic. The effects on these residents will vary according to their proximity to the horticultural area with the most likely affected people being those residents that are directly adjacent to the horticultural
block. With an increased distance from the site the ability to perceive any effects will decrease and the propensity to identify and report adverse affects will also decrease. There are ten properties that are adjacent to the horticultural area with approximately 20 to 30 residents on these properties. The local-level concerns are able to be mitigated by appropriate infrastructure design and management processes. A major social factor to the development of this project appears to be the impact of current waste management practices on the recreational and aesthetic values in the Ilparpa Valley. The current situation at the Alice Springs WSP has resulted in a loss of amenity for the residents of Alice Springs. The Ilparpa Valley is valued for the cultural, educational, natural and recreational opportunities that exist in that area, but opportunities to maximise and enjoy these values have been restricted due to issues such as mosquito and health concerns, offensive odours and burning practices aimed at managing the introduced reed Cumbunji. The use of recycled water at AZRI will allow these issues to be addressed and encourage different forms of recreation, and potentially, commercial ventures, to operate in the Ilparpa Valley.
Potential Impacts The use of recycled water at AZRI has the potential to have a range of both positive and negative impacts on the Alice Springs social and economic environment. In broad terms, the development of a wastewater treatment plant and reuse process will have significant benefits to the environment, community and the local economy. This will be achieved through the elimination of dry weather discharges to Ilparpa Swamp and an associated significant reduction of potential biting insect, and by supporting a viable horticultural industry.
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Potentially Positive Impacts Power and Water’s emissions, under the National Pollutant Inventory programme, will be reduced as the wastewater from the WSP will be reused rather than discharged. Ilparpa Swamp will be rehabilitated once dry weather overflows are ceased, with financial contributions from Power and Water and under the guidance of the Ilparpa Swamp Rehabilitation Plan. With the construction of the Alice Springs to Darwin Railway, there has been a loss of employment in Alice Springs with a number of jobs lost in the transport industry. In addition, global events have impacted on international tourism, resulting in a slowing down in the Alice Springs economy. The water reuse scheme is expected to create up to six permanent and 50 casual jobs in the region. Furthermore, the establishment of a horticultural development at AZRI is expected to increase the total table grape production in Central Australia by 30%, which will have flow-on beneficial effects for the regional community. The planned use of extracted water from the SAT project on soils in the Alice Springs area is as part of a drip irrigation scheme with high value horticultural crops, to provide a maximum economic benefit from the recycled water extracted from the soil aquifer treatment scheme using a system that minimises effects on plants and soils from slightly saline water. Therefore the provision of horticulture in Alice Springs will provide the benefit of increased economic activity to the town, including permanent and part time employment suitable for NT residents and possibly for backpacker tourists. This also provides a diversification of the town’s economy, which helps to provide a buffer against any down turn in the town’s traditional industries. It will also provide increased freight for the railway as the produce is expected to be sold Australia wide.
At a regional level, this development will contribute to the employment of Central Australian Aboriginal people as it will form a portion of the wider Centrefarm proposal. This proposal details expanded horticultural production in Central Australia and has significant social, educational, health and economic benefits for the Aboriginal people of this region. In addition, with the location of the horticulture scheme and AZRI next to the Desert Knowledge Precinct now under construction, there are synergies for both by their proximity. The knowledge and the experience of AZRI personnel and those operating the horticulture venture, can be passed on to those at the Desert People’s Centre, and similarly, the research and teaching at the Desert People’s Centre can benefit the further development of horticulture in Central Australia.
Potentially Negative Impacts At the local level any impacts will most likely be noticed by the residents directly adjacent to horticultural operations. These impacts are most likely to involve odours, noise, spraydrift and dust. These impacts, if anticipated and managed appropriately, should not adversely affect neighbouring stakeholders. The possibility of local adverse impacts affecting any persons is most likely to be the residents located to the east of the proposed horticultural area. As mentioned above, this will be approximately 280 people in the whole residential estate and 20 to 30 people directly adjacent to the proposed development. The following assessment of potential impacts, and subsequent development of safeguards and mitigation measures, was undertaken with the adjacent residents in mind.
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Odours Odour may be considered by local residents as a major on-going negative impact at the AZRI site, because of historical issues with offensive odours in the surrounding recreational amenities of the current WTP. There are two potential production areas for offensive odours, the SAT infiltration ponds and the pre-irrigation recycled water storage area. The potential of these two operations to produce offensive odours is low due to the treatment processes that the recycled water has undergone (i.e. chlorination) and the constant replenishment as the recycled water is moved throughout the site. However, if odours are created at the SAT or horticultural sites, they are likely to be constant because of the nature of the operations (i.e. continuously operating). The potential for odours to be recognised and perceived as an impact will largely depend on the strength and direction of the wind. In general the winds increase in strength as the day continues, calming at night, and the prevailing winds are normally from the south east. Under these conditions during the day there will be low likelihood of sensing the odours in the adjacent residential area and a slightly greater likelihood in sensing the odours at night and in the early morning. In the event of a westerly wind there may be a greater likelihood of noticing any odour.
Noise The extent of noise production will vary depending on the stage of development of the site. It would be expected that there would be a reasonably high level of noise produced during the development of the site including construction of temporary access tracks, vegetation clearing, excavation of basins and landscaping and revegetation of disturbed areas. The noise that is produced will be generated primarily by vehicles and possibly heavy machinery but should not continue for an extended duration.
Relatively constant sources of noise will be generated throughout the horticultural operations which may include tractors, vehicles, chemical spraying equipment, water pumps and bird deterrents. The use of high–volume sprayers to fertilise and apply fungicide can generate a large amount of noise; however, the necessity of this is restricted to times in January, September, October and November, for table grape crops. Another noise source is use of gas guns as a bird deterrent in pest management. It is expected that the gas gun will be in operation in September, October and November. This source of noise may have a significant impact on a large number of residents due to the high volume of the noise and the early hours of operation. The number of people that will be affected by noise will largely depend on the time of day that the noise is created. Activities such as the use of tractors and spraying equipment at night will be noticed by more people than day-time activities.
Dust Due to the arid location and proposed horticultural activities at AZRI, there will be dust produced during construction and general operations. The agents that may produce dust will predominantly include earth moving equipment, farming and general vehicles during the construction of the SAT basins and firebreaks. It is expected that the duration of the construction phase will be approximately two months for the SAT basins and three months for horticultural infrastructure development. Both of these developments may occur concurrently. Additional dust will be creating during planting of the crops and the installation of the irrigation. This will involve periods of relatively high dust production as each four hectare lot is prepared. During horticultural operations there will be activities that
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produce dust which may include the use of farming machinery and vehicles. The potential for dust to adversely impact on the neighbouring residents is relatively low due to the prevailing south-easterly winds. However in the event of a westerly wind, or an atmospheric inversion during high-dust producing operations, there is the potential to adversely impact on the neighbouring residents.
Spraydrift A variety of chemicals may used be in the horticultural operations including herbicides, fungicides, insecticides, growth regulators and fertilisers. The potential of adverse impacts on the residential neighbours will depend on a variety of factors including: • Compliance with relevant legislation
and accepted practices; • The level of training and skill of
operators; • Weather conditions and local
topography; • Mode of chemical application; • The formulation of the chemical; • Calibration and maintenance of
equipment; and • The crop type. The potential impacts of spraydrift on the neighbouring residents could include: • Damage to gardens and surrounds; • Effects on non-target crops and
pastures; • Effects on water quality and aquatic
life; • Effects on bee populations; and • Effects on human health and livestock. All agricultural chemicals are registered with the Australian Pesticides and Veterinary Medicines Authority (APVMA) whose role is to ensure that chemicals are effective and do not harm human health.
As part of this assessment the APVMA assesses the risk of spraydrift and communicates this to users. Adherence to the advice and regulations provided by the APVMA will significantly reduce the risk of adverse impacts.
Safeguards
Guidelines for Water Reuse From an environmental and agronomic view as well as issues of public health, there are major developments occurring in the regulatory approach to reuse of recycled water in horticulture and agriculture, as regulatory authorities clarify regulatory regimes for such schemes. Recent regulatory regimes developed by New South Wales, South Australia and Tasmania for recycled water reuse in horticulture provide an overview of the broad style of approaches being taken that combine sound public health and environmental needs while facilitating reuse. Table 8 in section 2.8.6 provides a summary of the different guidelines available and Table 9 provides a summary of the appropriate use for different classes of recycled water. It is proposed that the water delivered to the soil aquifer treatment scheme will be of a Class B or better. It is highly likely that the quality will be closer to Class A, because of the tertiary treatment process (which is not generally required for Class B). The Victorian and South Australian standards refers to Class B water as being with <100 E. coli org/100 ml, <20 mg/l BOD and <30 mg/l suspended solids. It is expected that the SAT water recovered will Class A and have unrestricted use. However, the current project has a precautionary approach and is using irrigation systems which minimise potential impacts to human health as well as the environment.
Public Health Approvals The proponents have previously provided a summary document to the Department of
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Health and Community Services (DHCS), which outlined the expected water quality, methods of application and safeguards in place to protect human health. On the basis of this document, DHCS have provided ‘in principal’ support for the proposed treatment and reuse scheme. The measures in place to protect human health include: • Provision of chlorinated (disinfected)
water to the SAT basins, with infiltration expected to further decrease the level of pathogens in the recycled water;
• A minimum period required before extraction of recycled water for reuse, to allow natural microbial processes to enhance water quality even further;
• Use of sub-surface application of recycled water to minimise spraydrift and use of low impact ground spray irrigators for any pasture irrigation, positioned away from residential areas;
• Incorporation of a minimum 50 m buffer between the horticultural site and residential areas; and
• Contingencies to shut-off irrigation water supplies in the event that monitoring shows that there is an unacceptable level of pathogens in the irrigation water (as per the SA guidelines for recycled water reuse).
Under the Public Health Act, all projects utilising recycled water require DHCS endorsement and approval and approvals can prescribe mechanisms to negate adverse impact to public health arising from exposure to treated recycled water and associated elements including soil contact and aerosol exposure, should it be decided that these are necessary in addition to the safeguards proposed.
Mitigation Against Loss of Rural Amenity A potential negative social and economic impact in the development of the SAT and
the use of recycled water for horticulture at AZRI is the perceived loss of amenity by the adjacent landholders. The people that are most likely to experience this perceived loss of amenity and to recognise adverse impacts are the residents whose properties are closest to the proposed development. In the interests of minimising any potential adverse impacts a series of safeguards have been developed to mitigate against loss of amenity.
Odour The potential for odours to affect local residents is very low because of a range of safeguards to be implemented, as described below: • Tertiary treatment of recycled water
prior to delivery to AZRI and SAT basins, and further polishing through SAT;
• The use of sub-surface irrigation, minimising exposure of recycled water to the air;
• Recycled water is stored in aquifers (compared with above ground storage areas) which reduces potential for odour or spillage;
• A minimum of 50 m has been set aside between residential areas and the proposed horticultural area as a buffer zone for odour and noise; and
• A minimum of 100 m between the residential areas and the holding area for recycled water as a buffer for odour.
Spraydrift While the potential of any adverse effects on the neighboring residents is very low there are a number of practices that are commonly used in the horticultural industry that will reduce the possibility of spraydrift occurring: • Use of an enhanced vegetative buffer
of a minimum of 50 m around the proposed horticultural area;
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• Take into account the nearby residents and other facilities on/near the site by only spraying in low wind conditions and preferably when any spraydrift would not move towards the nearby residents;
• Avoid spraying in adverse weather conditions including westerly winds, in high temperatures with low humidity;
• Keep records of pesticide use as per acceptable industry practice;
• Ensure that all operators are appropriately trained; and
• Ensure that all equipment is maintained and calibrated appropriately and follow all other accepted industry practices.
Noise During the construction and operational phases, the noise impact can be reduced by management controls such as restricting the hours of operation. Hours of operation during construction will need to comply with the Waste Management and Pollution Control Act and the draft Waste Management and Pollution Control (Environmental Noise) Regulations. Under this legislation the AZRI site would be classed as an Industrial and Utility Premises and the residential area to the east would be classed as a Noise Sensitive Premises. The draft Waste Management and Pollution Control (Environmental Noise) Regulations set times and maximum noise limits for both AZRI and the rural residents, and will need to be complied with. It is recognised that the current practice of using gas guns to scare birds away from horticultural crops has created concern amongst residents. Therefore, it is recommended that alternative methods of bird fright be investigated. If alternative bird deterrents are not cost effective or appropriate then the current practice of advertising intended use times needs to be continued and the horticulturalist has the option of applying for approval to exceed maximum noise pollution levels as
described in Part 3 of the draft Waste Management and Pollution Control (Environmental Noise) Regulations.
The enhancement of the vegetation barrier along the eastern boarder of the proposed horticultural site will significantly reduce the level of noise that will be noticed by the adjacent residents. If there is excessive noise being produced and difficulties in adhering to the draft Waste Management and Pollution Control (Environmental Noise) Regulations then controls may be required and should comply with Australian Standards 2436-1981 Guide to Noise Control on Construction, Maintenance and Demolition Sites.
Dust A variety of approaches can be adopted to ensure that dust is not adversely impacting on any neighbouring residents; these include appropriate design and implementation, containment of dust and site improvement. The layout of the site and the installation of an internal road network is expected to significantly reduce the level of dust leaving the site. The use of firebreaks as vehicle routes should be strictly limited to use for property management by AZRI and not used for horticultural purposes, as this will limit the amount of dust that can affect neighbours. Appropriately designed and constructed roads will also reduce the amount of dust that is produced. The planned staged clearing of land (five, four hectare lots per year to be placed under cultivation) will ensure that vegetation is retained, thus reducing dust production. The vegetation that is cleared can potentially assist in dust suppression by placing significant habitat features (trunks, hollow bearing logs etc.) in the vegetation buffer and all other green waste can be mulched on-site. Use of this mulch on-site can assist in dust and weed control. The enhanced vegetation buffer will act as means of containing dust that is produced within the AZRI during operations.
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The use of drinking water to suppress dust during high production activities such as the ripping of planting lines may be necessary if there are adverse weather conditions. Alternatively, if the weather conditions are adverse it may be appropriate to wait for more appropriate conditions. If there are areas, such as in the rows between trellises, which are producing high amounts of dust that is not being contained, then it may be necessary to apply some form of cover. Options for this may include organic mulch, hydromulch, or appropriate grasses.
Privacy Issues of loss of privacy may be a concern to some residents adjacent to AZRI. Measures to ensure that privacy is not impacted upon include: • Enhancement of the 50 m vegetation
buffer to provide an adequate screen; • Ensuring that the external boundary
firebreak is only used for AZRI property management purposes; and
• Locating the proposed horticultural site access road away from the eastern boundary, to avoid large volumes of traffic travelling close to residential property boundaries.
Management of Cumulative Impacts The potential impacts of excessive noise, odours, spraydrift, and dust may be relatively minor when considered individually or when occurring sporadically, however, in culmination or in regular frequency these impacts may create feelings of frustration in the adjacent residential area. These residents occupy rural properties and presumably wish to experience the benefits of their rural lifestyle. These benefits may be quite intangible but may include feelings of isolation, tranquillity and independence. The perceived loss of these values through
a culmination of impacts may create feelings of resentment towards the proposed project. The safeguards that have been described above will possibly mitigate all potential impacts and the rural residents may not have their rural amenity degraded. It is strongly suggested that a senior person from within the SAT and horticultural project be available to discuss any concerns and potentially attend community meetings, in order to address any perceived impacts that the rural residents may have. This person should ideally have good communication skills, a commitment to maintaining good relationships and have the authority to address residents concerns, if appropriate. This representative should also take on the maintenance of a complaint register so that data can collected and operations modified if appropriate and/or possible.
Agrochemical Management Modern farm management uses pesticides and inorganic fertilizers. All agrochemicals that may be used have been through an approval process operated by the Australian Pesticides and Veterinary Medicines Authority (APVMA) which is an Australian government authority responsible for the assessment and registration of pesticides and veterinary medicines and for their regulation up to and including the point of retail sale. This authority approves use of the products and on specific crops within Australia. Within the Northern territory, while not mandatory, it is recommended that farm users of agrochemicals have an approved Chemcert Certificate (or equivalent) for use of agrochemicals. Changes to the Northern Territory administration of the farm use of agrochemicals (expected during 2005) will also required users to adhere to label recommendations for use of the products. With all pesticide use there are public health and occupational health and safety issues and it would be expected that the project would meet these statutory requirements.
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The project expects to use micro-irrigation systems throughout and in this type of irrigation system only a very small part of the total site area is irrigated. The project is in an arid region. These two factors alone mitigate against the movement of any pesticide into the groundwater through water percolating downwards and this issue is considered to be a very low risk. Areas of sprinkler irrigation are not expected to use significant amounts of pesticides.
Summary of Potential Impacts and Management A summary of potential impacts and proposed safeguards and contingency measures are summarised in Table 26. To determine the significance of impacts that may occur, Australian Standard 4360 (1999) Risk Management was used (Appendix 4). Using this standard, each potential impact is assessed in terms of the likelihood of occurrence and the consequence of occurrence. The product of these two scores gives an overall risk rating, providing guidance on the significance of the management strategies required.
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Table 26: Summary of Potential Impacts, Safeguards, Monitoring and Remedial Actions for Socio-Economic Environment.Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Elimination of dryweatherdischarge toIlparpa Swamp
Transfer ofrecycledwater fromwastestabilisationponds to SATsite
Low None required – environmentalbenefits to Ilparpa Swamp
None required None required
Dust ConstructionClearing
High Minimise vehicle access to thatnecessaryAvoid movement on boundaryfirebreaksRevegetate disturbed areasRemove waste soil if notrequired for use on site
Daily assessment of climaticconditions and dust generationduring constructionMaintain complaints register
Cease activity during strongwindsModify surface of access roads,where expected high use
Expansion of landuse options
Operation Low None required – availability ofrecycled water providesopportunity for otherdevelopment, synergies withDesert Knowledge Precinct and
None required None required
SAT
Increase in longterm, widespreadgroundwaterlevels standingwithin < 10 m ofthe surface
Operation High Investigations of groundwaterconditions, infiltration tests andgroundwater flow modelingprovide confidenceGroundwater of suitable depthto avoid mounding impacts onsoils and vegetationExperience with similarpalaeochannel conditions inAlice Springs
Installation of extensivegroundwater monitoring networktargeting the palaeochannel andthe more shallow permeablelayers radiating outward fromthe SAT Basins to the AZRI siteboundaries
Install infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannel or extractgroundwater and inject intoShannon formationDecrease volume of recycledwater disposed of through SATCease SAT operations
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Significant lateralmovement ofgroundwateroutsidepalaeochannel
Operation High Investigations of groundwaterconditions, infiltration tests andgroundwater flow modelingprovide confidenceExperience with similarpalaeochannel conditions inAlice Springs
Installation of extensivegroundwater monitoring networktargeting the palaeochannel andthe more shallow permeablelayers radiating outward fromthe SAT Basins to the AZRI siteboundaries
Do nothing where water qualityor depth below ground surfaceis not considered an issueInstall infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannel or extractgroundwater and inject intoShannon formationCease SAT operationsPump out of basins and removeoff-site poor quality recycledwater
Groundwatermigration to otheraquifer systems
Operation Medium Investigations of groundwaterconditions, infiltration tests andgroundwater flow modelingprovide confidenceExperience with similarpalaeochannel conditions inAlice Springs
Routine monitoring of existingnetwork of monitoring andoperational extraction bores forpotential changes
Do nothing where water qualityis not considered an issueCease SAT operations
SATcontinued
Preferential flowof lower qualitygroundwater fromquaternarysystems tounderlyingTertiary Systemsalong existingbore networks
Operation Medium Routine monitoring of waterquality
Routine monitoring of waterquality
Do nothing where water qualityis not considered an issueReplace or repair bore networksCease SAT operations
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
SATcontinued
Contamination ofexistinggroundwater withmicrobialpathogens
Operation High Routine monitoring of extractionwater quality
Routine monitoring of extractionwater quality
Cease SAT operationsInstall infiltration bores thoughthe lower permeability layerpresent immediately above thepalaeochannel or extractgroundwater and inject intoShannon formationIncrease extraction to recovercontaminated waterIncrease tertiary treatment trainto provide further polishing (e.g.filtration)
Horticulture Dust ConstructionClearingOperation
High Minimise vehicle access to thatnecessaryAvoid movement on boundaryfirebreaksRevegetate disturbed areasDesign layout to place accessroads in centre of site ratherthan on peripheryEnhance buffer areas with poorvegetative cover
Daily assessment of climaticconditions and dust generationduring constructionMaintain complaints registerMonitor revegetation success
Cease activity during strongwindsSeal access roads, whereexpected high use
Increasedeconomic activity
Operation Low None required – positiveimpact, employmentopportunities and availability offresh produce
None required None required
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Application ofirrigation waterwith highpathogeniccontent
Operation Medium Routine monitoring of extractionwater qualityUse only if within recycled wateruse guidelines for different croptypesRegular chlorination of irrigationpipes to reduce build up ofpathogens
Routine monitoring of extractionwater quality
Cease irrigationIncrease tertiary treatment trainto provide further polishing (e.g.filtration)
Horticulturecontinued
Pest species ConstructionOperation
Low Areas requiring drainage will beconstructed so that no poolingcan occur within the drainsUse amber external lighting oninfrastructure fitted with lightsMaintain a clean and tidy workarea to ensure scavenger birdsare not attracted to the siteEnsure putrescible bins areclosed and no wastes are leftuncoveredUse of sub-surface drippers tominimise pest species attractedto moist soil environmentsStorage of water in sealedholding tanks
None required other thannormal work site maintenancechecksMaintain complaints register
Undertake corrective action
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Horticulturecontinued
Odour Operation Low Experience elsewhere showsodour is not a problemUse sub-surface drippers andsealed holding tanks tominimise exposure of recycledwater to airMaintain minimum 50 m bufferdistance from residential areasaround all sources of recycledwaterEnhance buffer areas with poorvegetative cover
Maintain complaints registerMonitor revegetation success
Identify source of odour andtake corrective action,depending on source
Noise ConstructionOperation
High Limit hours of construction workto between 0700 and 1900 hrsAdvertise intended use of birdfright (gas guns) as per currentpracticeMinimise frequency of use andprevent use before 0700 hrsMaintain minimum 50 m bufferdistance from residential areasDesign layout to place accessroads in centre of site ratherthan on peripheryEnhance buffer areas with poorvegetative cover
Maintain complaints registerInvestigate alternative methodsof pest bird removalMonitor revegetation success
Take corrective action
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Project Component Potential Impact Activities Risk Category Safeguards Monitoring Remedial Actions
Spraydrift ofpesticides orherbicides
Operation Medium Maintain minimum 50 m bufferdistance from residential areasOnly use chemicals inaccordance with labeling andlicensingUse only herbicides andpesticides licensed for use onraw produce and crops grownMinimise use of pesticides andherbicides to that necessary forefficient operationsEnhance buffer areas with poorvegetative cover
Assessment and recording ofclimatic conditions onnominated days of intended useMaintain register of chemicaluseMonitor revegetation success
Cease activity during strongwinds
Movement ofpesticides orherbicides togroundwater
Operation Low Arid climate with low rainfallminimises risk of infiltrationUse of sub-surface drippersminimises risk of infiltration frommovement of surface water
Maintain register of chemicaluseRoutine monitoring ofgroundwater quality
Cease application of chemicalsand identify source, wherepossible (note, source could beoff site, but this would beevident in groundwatermonitoring results)
Horticulturecontinued
Privacy Operation Medium Design layout to place accessroads in centre of site ratherthan on peripheryMaintain minimum 50 m bufferdistance from residential areasEnhance buffer areas with poorvegetative cover
Maintain complaints registerMonitor revegetation success
Take corrective action,depending on nature ofcomplaint
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Further Investigation and Assessment As recommended, a senior person from within the SAT and horticultural project be available to discuss any concerns and potentially attend community meetings. Investigation of the buffer zone surrounding
the horticultural site needs to be undertaken, once the horticultural layout has been determined, to locate those areas of the buffer which require enhancement.
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ENVIRONMENTAL MANAGEMENT PLAN Environmental Commitment Power and Water has a commitment to Ecologically Sustainable Development (ESD) as evidenced in their Environmental Policy and Vision Statement. Power and Water has a long term aim of sustainable provision of services to customers, an objective of protecting all aspects of the environment and minimising impacts arising from their use of resources. Power and Water is committed to: • A pro-active risk-based approach to
environmental management that leads to continual improvement in service;
• Seeking solutions for the provision of sustainable services to their customers by ensuring environmental factors are considered in the planning for new services and significant upgrades of assets;
• Protecting or enhancing the environmental values of air, land and water under their control, while recognising obligations to employees, customers and the community;
• Engaging with the community on environmental issues of mutual interest;
• Minimising environmental impacts that can be reasonably and realistically controlled while achieving business objectives;
• Providing training and resources to enable all staff to contribute to achieving environmental outcomes and objectives; and
• Meeting legislative and regulatory obligations.
The current project seeks to affirm these commitments through: • Detailed investigations into the
feasibility of the proposed project prior to implementation;
• Identification of the full range of potential impacts and how these can be managed or mitigated against;
• An ongoing and open community consultation process, including preparation of this PER; and
• Use of an independent consultant to review the research findings and report on any gaps in knowledge and understanding.
Environmental management of the project will incorporate Power and Water’s approach to environmental sustainability and follows the principles inherent in ESD: • The precautionary principle -
namely, that if there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. For this project, the approach includes staged implementation with constant feedback from monitoring results to assess the success or otherwise of the programme and management actions required. The detailed investigations undertaken as part of this project means that the threat of serious or irreversible environmental damage associated with the construction and operation of the SAT and horticultural schemes is largely known and as such, appropriate measures to ensure environmental degradation does not occur at the proposed project site can be implemented;
• Inter-generational equity - namely, that the present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations. Risks to inter-generational equity includes the potential for long term degradation of sensitive habitats and vegetation types. Measures to prevent this have
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been implemented at all stages of the project planning; for example, the SAT basins have been sited such that the recycled water is not likely to impact on drinking water supplies; the horticultural programme is planned to be managed in away to minimise any pong term impacts on soils and both schemes have taken into account cultural sensitivities at the proposed project site;
• Conservation of biological diversity and ecological integrity – namely, that conservation of biological diversity and ecological integrity should be a fundamental consideration. Measures have been proposed for implementation at all stages of construction and operation to ensure the biological diversity and ecological integrity of the site would not be compromised; and
• Improved valuation and pricing of environmental resources – namely, that environmental factors should be included in the valuation of assets and services, such as polluter pays, full life cycle costing, and utilising incentive structures/market mechanisms to meet environmental goals. The non-financial value of natural resources such as Ilparpa Swamp and the existing groundwater supplies were of prime consideration when planning for a water reuse scheme or Alice Springs.
With the implementation of the mitigation measures provided in this PER, it is considered the proposed project would be undertaken in accordance with the principles of ESD.
Environmental Management of Construction Activities The construction activities are likely to include: • The preparation of the SAT basins; • The installation of pipelines from the
existing Recycled Water Transfer Pipeline to the SAT basins;
• Installation of extraction wells and monitoring wells;
• Clearing of areas as required (staged approach) for horticultural development;
• Building of infrastructure associated with the both the SAT and horticultural projects.
Each of the impacts associated with these activities have been included in Construction Environmental Management Plans for the SAT scheme and the horticultural scheme (Appendices 7 and 8, respectively).
Environmental Management of Operational Activities The operational activities are likely to include: • Maintenance of SAT basins and
infrastructure; • Horticultural activities including
planting, harvesting and site maintenance; and
• Collection of monitoring data. Each of the impacts associated with these activities have been included in Operation Environmental Management Plans for the SAT scheme and the horticultural scheme (Appendices 9 and 10, respectively).
Measures for Ensuring Safeguards are Effectively Applied Allocation of responsibility for different aspects of the proposed project is a method of ensuring that the safeguards provided in this PER and the associated Construction and Operation EMPs are effectively applied. The overall responsibility for the main components of the project is as follows: • Construction of SAT basins – Power
and Water;
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• Operation of SAT basins – Power and Water;
• Monitoring of the quality of recycled water entering the SAT basins - Power and Water;
• Extraction of recycled water – DBIRD; • Application of recycled water – private
horticulturalist, as part of lease agreement with DBIRD; and
• Monitoring of the quality of recycled water being used for horticulture - private horticulturalist, as part of lease agreement with DBIRD.
Agreement between Power and Water and DBIRD will need to be reached to determine who will actually undertake water and soil monitoring and where these samples will be processed. It is possible to use the existing laboratory at AZRI for this purpose. The associated Construction and Operation EMPs can be used by Power and Water and DBIRD to ensure all contractors involved in infrastructure development adhere to the environmental safeguards provided and this measure can be included in contractual documentation. This is particularly relevant for issues such as soil erosion, dust generation, impacts to social amenity and land clearing operations. In addition, this PER and the associated Construction and Operation EMPs include contingencies for failure of safeguards to provide the expected environmental protection. These contingencies have been
provided to ensure that, at no stage, will impacts be incurred that are not manageable.
Periodic Review Periodic review of the Operation EMPs will be required to ensure they remain valid to operations. It is recommended that this review be undertaken by the relevant responsible bodies (as outlined above) on a bi-annual basis during the first year of operation and annually thereafter. This could occur at the same time as corporate environmental reporting is undertaken, to integrate this process with existing environmental practices within each organisation. The Construction EMPs for the SAT and horticultural schemes will only be relevant during the initial construction phase and infrastructure development and therefore will not require periodic review. The review should include: • An audit of environmental condition,
including during and at the end of the construction phases of each scheme;
• An audit of the effectiveness of recommended safeguards, where they have been applied, including a description of the outcomes; and
• An update of environmental safeguard procedures as required to suit changing environmental conditions, should this occur.
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FURTHER READING Acer Vaughan. 1990. Report on Town Basin Water Use and Reclaimed Sewage Effluent Use.
Report prepared for the Power and Water Authority. ACT Planning and Land Authority. 1997. ACT Environment and Health Wastewater Reuse
Guidelines. ACT Government, Canberra. Arid Lands Environment Centre. 2000. Ilparpa Commonage: Issues and Actions. Report
funded by the National Land Care Programme. Arid Lands Environment Centre, Alice Springs.
Australian Groundwater Consultants Pty Ltd. 1983. Alice Springs Water Supply Pollution
Protection Study – Final Report. Report prepared for the Power and Water Authority. Barnetson J and Richardson M. 2002. Desert Knowledge Precinct Fauna Survey. Alice
Springs Desert Park. Beavers PD. 1996. Interim Guidelines for Reuse or Disposal of Reclaimed Wastewater. Qld
Department of Natural Resources, Brisbane. Berry K. 1991. Monitoring Development Alice Springs Commonage. Power and Water
Authority, Water Resources Branch, Alice Springs, NT Report No. 02/1991A. Berry K. 1992. Alice Springs Town Basin Water and Salt Balance Studies. Power and Water
Authority, Water Resources Branch, Alice Springs, NT Report No. 02/1992A. Bouwer H. 2002. Artificial recharge of groundwater: hydrology and engineering. Hydrogeology
Journal 10:121-142. Chu YJ, Jin Y, Baumann T and Yates MV. 2003. Effects of Soil Properties on Saturated and
Unsaturated Virus Transport through Columns. Journal of Environmental Quality 32:2017-2025.
Cole J and Pavey C. 2003. Fauna Survey of the Desert People’s Knowledge Centre Site.
Unpublished report for NT Parks and Wildlife Commission. Crassweller C. 2004. An Archaeological Survey for the Proposed Alice Springs Water Reuse
Project. Report prepared for the Power and Water Corporation. Dames and Moore. 1987. Alice Springs: Assessment of Environmental Effects of Existing
Sewage Treatment and Disposal, and Means of Overcoming Adverse Effects. Report prepared for Northern territory Water Authority.
DBIRD. 2004. Survey of Culturally Significant Trees in the Proposed Horticulture Site of AZRI.
Unpublished report. De Araujo A, Konig A and Ceballos B. 2003. Soil and water changes after sewage irrigation
practice in semi-arid region of Northeast Brazil. Water Sci. Technol. Water Supply 3. Department of Environment and Heritage. 2000. Guidelines for Sewerage Systems - Use of
Reclaimed Water. Paper No. 14, Canberra.
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Dettrick D and Gallagher S. 2002. Environmental Guidelines for the Use of Recycled Water in Tasmania. Environment Division, Department of Primary Industries, Water and Environment, Tasmania.
DIPE. 1999. Alice Springs Land Use Structure Plan 1999. Lands, Planning and Environment,
Northern Territory Government, Darwin. DIPE. 2001. Land Resources of the Alice Springs Area. Department of Infrastructure,
Planning and Environment, Darwin. DIPE. 2002. Land Clearing Guidelines. Northern Territory Government, Technical Report
27/2002. DIPE. 2004. Alice Springs Town Plan 1992. Department of Infrastructure, Planning and
Environment, Northern Territory Government, Darwin. Emerson WW and Weissman D. 1997. Compaction of Soils Irrigated with Bore Water in
Central Australia. CSIRO Land and Water Technical Report 12/97. Environment Protection Agency and Department of Health. 1999. South Australia Reclaimed
Water Guidelines. Government of South Australia, Adelaide. Fox P, Houston S, Westerhoff P and Drewes JE. 2001. An Investigation of Soil-Aquifer
Treatment for Sustainable Water Reuse. National Centre for Sustainable Water Supply, Arizona State University, Tempe, Arizona, USA.
Fox P, Narayanaswamy K, Genz A and Drewes JE. 2001. Water quality transformations during
soil aquifer treatment at the Mesa Northwest Water Reclamation Plant, USA. Water Sci Technol. 10:343-350.
Gates W and Janik L. 2004. Characterisation of Physical and Geochemical Nature of
Unsaturated Sediment Cores.
Gerba CP, Pepper IL and Whitehead LF. 2003. A risk assessment of emerging pathogens of concern in the land application of biosolids. Water Sci. Technol. 46:225.
Hillman JP, Hill J, Morgan JE and Wilkinson JM. 2003. Recycling of sewage sludge to
grassland: A review of legislation to control the localisation and accumulation of potential toxic metals in grazing systems. Grass Forage Sci. 58:101.
Ho GE, Gibbs RA, Mathew K and Parker WF. 1992. Groundwater recharge of sewage effluent
through amended sand. Water Research 26:285-293. Hostetler SD. 2002. Recharge to the Amadeus Basin Around Alice Springs, Central Australia.
Water Program, Bureau of Rural Sciences, Canberra. Isbell RF. 1996. The Australian Soil Classification. CSIRO Publishing, Collingwood, Victoria. Jolly ID, Walker GR and Narayan KA. 1994. Floodplain recharge processes in the Chowilla
anabranch system, South Australia. Australian Journal of Soil Research 32:417:435. Jeuken, M. 2004. A Hydrogeological Study of the Surficial Aquifers of South Alice Springs.
Honours Thesis, School of Chemistry, Physics and Earth Sciences, Flinders University, SA.
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Knapton A. 2004a. Alice Springs Water Reuse Scheme Soil Aquifer Treatment Project, Volume 1 - Site Characterisation. Draft, Water Resources Branch, Division of Natural Resources, DIPE, Alice Springs.
Knapton A. 2004b. Alice Springs Water Reuse Scheme Soil Aquifer Treatment Project Volume
4 – Groundwater Modelling. Draft, Water Resources Branch, Division of Natural Resources, DIPE, Alice Springs.
Knapton A and Lennartz R. 2004. Alice Springs Water Reuse Scheme Soil Aquifer Treatment
Project Volume 2 - AZRI Site Investigations. Draft, Water Resources Branch, Division of Natural Resources, DIPE, Alice Springs.
Knapton A, Pavelic P, Dillon P and Low B. 2004a. Field Infiltration Tests with Potable Water to
Predict Hydraulic Behaviour of a Soil Aquifer Treatment Trial for Alice Springs, Northern Territory. Draft, Water Resources Branch, Division of Natural Resources, DIPE & CSIRO Land and Water.
Knapton A, Jolly P, Pavelic P, Dillon P, Barry K, Mucha M and Gates W. 2004b. Feasibility of a
Pilot 600ML/yr Soil Aquifer Treatment Plant at the Arid Zone Research Institute. Water Resources Branch, Conservation and Natural Systems, DIPE Technical Report No. 29/2004.
Kowal NE. 1982. Health Effects of Land Treatment: Microbiological. Heralth Effects Research
Laboratory, EPA, Cincinnati, USA. Lennartz R. 2005. Soil Aquifer Treatment - AZRI Soil Investigation. Land and Resource
Assessment, DIPE. Medema GJ and Stuyfzand PS. 2002. Removal of microorganisms upon basin recharge, deep
well injection and river bank filtration in the Netherlands. In Management of Aquifer Recharge for Sustainability Proceedings of the Fourth International Symposium on Artificial Recharge. Balkama Press, Adelaide.
National Center for Sustainable Water Supply (NCSWS). 2001. An investigation of soil-aquifer
treatment for sustainable water reuse. U.S. Environmental Protection Agency and Arizona State University, Tempe, Arizona.
National Research Council. 1994. Groundwater Recharge Using Waters of Impaired Quality.
National Academy Press, Washington DC. NSW Recycled Water Coordination Committee. 1992. NSW Guidelines for Urban and
Residential Use of Reclaimed Water. NSW Government, Sydney. Paltridge R and Latz P. 2003. Alice Springs Airport Fauna and Flora Survey. Unpublished
report prepared for the NT Airports Corporation. Pavelic P, Mucha M, Barry K, Dillon P and Hanna J. 2004. Laboratory Column Study on the
Effect of Wastewater Quality on Soil Clogging During Soil Aquifer Treatment. Draft, CSIRO Land and Water.
Power and Water Corporation. 2003. Alice Springs Reclaimed Water System Pathogen
Report. Unpublished internal report.
Public Environment Report, Alice Springs Water Reuse Scheme
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Power and Water Corporation. 2004. Notice of Intent Alice Springs Water Reuse Scheme Soil Aquifer Treatment Scheme Arid Zone Horticulture Addendum. Unpublished internal report.
Quanrud DM, Carroll SM, Gerba CP and Arnold RG. 2003. Virus removal during simulated
soil-aquifer treatment. Water Research 37:753-762. Quanrud DM, Hafer J, Karpiscak MM, Zhang J, Lansey KE and Arnold RG. 2003. Fate of
organics during soil-aquifer treatment: sustainability of removals in the field. Water Research 37: 3401–3411.
Quanrud DM, Karpiscak MM, Lansey KE and Arnold RG. 2004. Transformation of effluent
organic matter during subsurface wetland treatment in the Sonoran Desert. Chemosphere 54: 777–788.
Quinlan T and Woolley DR. 1969. Geology and Hydrology, Alice Springs Town and inner Farm Basins, Northern Territory. Bureau of Mineral Resources, Geology and Geophysics, Department of National Development Bulletin 89.
Radcliffe JC. 2004. Water Recycling In Australia: A Review. Australian Academy of
Technological Sciences and Engineering, Victoria. Rusin PA, Maxwell SL, Brooks JP, Gerba CP and Pepper IL. 2003. Evidence for the absence
of Staphylococcus aureus in land applied biosolids. Environ. Sci. Technol. 37:4027-4030. SA EPA. 1999. South Australian Reclaimed Water Guidelines. Government of South
Australia, Adelaide. Schmidt MWI, Skjemstad JO and Jager C. 2002. Carbon isotope geochemistry and
nanomorphology of black soil carbon: Black chernozemic soils in central Europe originate from ancient biomass burning. Global Geochemical Cycles 16.
Sinclair Knight Merz. 2000a. Alice Springs Urban Water Management Strategy: Sewage
Treatment and Effluent Management Report. Report prepared for the Power and Water Authority.
Sinclair Knight Merz. 2000b. Alice Springs Urban Water Management Strategy: Aquifer
Storage and Recovery Feasibility Report. Report prepared for the Power and Water Authority.
Smith J and Firth R. 2004. Preliminary Assessment of Coolabah / Ironwood Vegetation
Patches at Alice Springs Airport. Unpublished report prepared for NT Airports Corporation.
Stevens BG. 1986. Arid Zone Research Institute RN620 Bore Replacement Investigation Jan
1985 – Jun 1986. Water Resources Division, Department of Mines and Energy Report No. 22/1986.
Toze S, Hanna J, Smith A and Hick W. 2002. Halls Head Indirect Treated Wastewater Reuse
Scheme. CSIRO Land and Water report to Water Corporation, Western Australia. US EPA. 2004. Guidelines for Water Reuse. United States Agency for International
Development.
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van de Graaff R and Patterson RA. 2001. Explaining the Mysteries of Salinity, Sodicity, SAR and ESP in On-site Practice. In Proceedings of On-site ’01 Conference: Advancing On-site Wastewater Systems Ed: RA Patterson and MJ Jones. Lanfax Laboratories, Armidale.
Varidel M. 2003. Alice Springs Effluent Irrigation System Review. Unpublished report
prepared for Power and Water. Verstraeten IM, Heberer T, Vogel JR, Speth T, Zuehlke S and Duennbier U. 2003. Occurrence
of endocrine-disrupting and other wastewater compounds during water treatment with case studies from Lincoln, Nebraska and Berlin, Germany. Periodical of Hazardous, Toxic and Radioactive Waste Management 7.
Victorian EPA. 2002. Guidelines for Environmental Management: Use of Reclaimed
Wastewater. Victorian Government, Melbourne. Wright M. 1959. A Soil Survey of the Township Area of Alice Springs, NT. CSIRO Divisional
Report 2/59.
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Appendix 1: PER Guidelines
Draft PER GuidelinesAlice Springs Water Reuse SchemeJune 2004
1
DRAFT GUIDELINES FOR THE PREPARATION OF APUBLIC ENVIRONMENTAL REPORT
ALICE SPRINGS WATER REUSE SCHEME:SOIL AQUIFER TREATMENT SCHEME AT
ARID ZONE RESEARCH INSTITUTEHORTICULTURE ADDENDUM
JUNE 2004
TABLE OF CONTENTS
Introduction.............................................................................................................................................. 1Content of a PER .................................................................................................................................... 2
1. Executive Summary ..................................................................................................................... 22. Description of the proposal........................................................................................................... 23. Environmental Constraints and Issues, Potential Impacts and Proposed Safeguards ................ 4
Administrative Requirements .................................................................................................................. 7
Project Description
The Alice Springs Water Reuse Scheme broadly involves:
1. additional treatment of effluent from the Waste Stabilisation Ponds to produce highquality recycled water (by use of a Dissolved Aeration Flotation (DAF) system);
2. developing underground storage (water banking) of recycled water by using suitablegeological formations (aquifer); and
3. recovery of “banked” water for irrigation or other high value use on or near the Arid ZoneResearch Institute.
Introduction
The purpose of the Public Environmental Report (PER) is to provide the Government withconcise and comprehensive information regarding the design, construction and operation ofthe proposed Alice Springs Water Reuse Scheme. It should contain sufficient information toenable understanding and assessment of the scope and environmental implications of theproposal. The PER should clearly identify the main environmental impacts associated withthe development and should contain a management strategy to minimise these impacts.
Information should be presented in a concise format, using maps, overlays, tables anddiagrams where appropriate to clarify the text.
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Content of a PER
1. Executive Summary
The Executive Summary is to include a brief outline of each section within the PublicEnvironmental Report (PER). The summary should be a concise outline of the mattersdiscussed in the main body of the document, to allow the reader to quickly obtain a clearunderstanding of the proposal, its environmental implications and management objectives.
2. Description of the proposal
This section should describe the development proposal to allow a detailed understanding ofinfrastructure design and engineering and all stages of construction, operation andmanagement of the Scheme and include relevant plans, photos and maps.
The PER should provide a history of the proposal and provide a full description of the AliceSprings Water Reuse Scheme.
The PER should provide information of where this technology has been used elsewhere,giving an indication of its success (compared to conventional treatment and disposal),describing monitoring and environmental management techniques and outlining theperformance measures used. If possible, the PER should use examples of where aquiferrecharge schemes have been used for the injection of treated effluent or wastewater ratherthan to provide storage capacity for “clean” water.
The PER is to provide justification for the proposal (using the examples of where thetechnology has been applied elsewhere) including the chosen design (e.g. the location ofinfiltration ponds and extraction sites), environmental management measures, monitoringcriteria as well as proposed performance measures. The PER is to demonstrate how theaquifer was selected for this purpose (referencing interstate or overseas guidelines onaquifer selection for recharging purposes).
This section should also examine alternatives to the proposal. This includes alternatives tothe water banking component of the proposal as well as alternatives to the end use of theextracted groundwater.
Aspects to be covered include:
General
(a) Description of the proposal and all its components (including proposed use of treatedeffluent for irrigation that has not undergone soil aquifer treatment – quantities andlocality).
(b) Project schedule, including staging of development and the timing of the stages.
(c) Location and design criteria for each component of the project including designlimitations imposed by site characteristics.
(d) Land requirements, land tenure, acquisition requirements (permits, rezoning andnative title), and the tenures under which the project would be held including details ofrelevant legislative processes required to grant proposed tenure.
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(e) Infrastructure requirements and specifications (permanent and temporary) andancillary activities (e.g. storage/laydown areas etc).
(f) The layout of the proposal, including all elements such as ponds, extraction wells,agricultural land, buildings, roads etc.
(g) Waste management. Outline plans for waste management including prevention,treatment and disposal.
(h) Outcomes of any public consultations for the proposal.
Soil Aquifer Treatment
(i) Design and engineering details of infiltration ponds and any associated ancillaryfacilities.
(j) The process of geopurification, that is, the physical and biological processes thatenhance water quality.
(k) Proposed construction methods.
(l) Describe the texture, structure and properties of the soils in the floor and walls of theinfiltration basins, including their permeability and infiltration capacity.
(m) Describe proposed amount of treated effluent to enter infiltration basins per annumand its quality, including salinity levels. Provide justification for proposed water qualitystandards to be used to determine acceptability of treated effluent for infiltration.
Horticulture/Agricultural Site
(n) Design and engineering details of extraction wells and pumping systems and irrigationsystems.
(o) Application methods of treated effluent.
(p) Proposed crops to be irrigated and their end use.
(q) Amount of banked water to be used for irrigation purposes per annum.
(r) Detail any proposed vegetation clearance.
(s) Identify and justify water quality standards that are to be met before extracting waterfor irrigation purposes.
(t) Fire control. Details of control measures, in the event of a fire outbreak, should beincluded. As per the Bushfires Act 1996, any landholder is required to ensure a fourmetre firebreak is installed and maintained along all boundaries.
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3. Environmental Constraints and Issues, Potential Impacts and ProposedSafeguards
This section examines those aspects of the existing biophysical and socioeconomicenvironment that may be affected by the proposal, including site capability and suitability.
Management practices or safeguards should be expressed as a series of commitments.These commitments and any associated discussion of impacts should be included inappropriate sections and subsections. Each commitment should be numbered consecutivelyand highlighted to stand out from the surrounding text. These commitments will form thebasis for the Environmental Management Plan (EMP) for the site.
Aspects to be covered include (but are not limited to):
3.1 Soil Disturbance and Salinity
Existing Environment
• Describe the salinity of soils that may receive the recovered groundwater foragricultural and horticultural use.
• Describe the texture, structure and properties of the soils in the floor and walls of theinfiltration basins.
Potential Impacts
• Describe the potential for increase in salinity of soils as a result of using recoveredgroundwater.
• Assess the potential for the salinisation of soils to the degree where they are no longerfit for use for horticulture and agriculture and calculate the number of cropping yearsbefore salinity prevents further cropping.
• Assess the potential for soil erosion to occur at both the infiltration ponds and the landused for horticultural purposes.
Safeguards
• Describe in detail the methods that will be used to prevent salinisation of agriculturaland horticultural soils;
• If soil leaching is an option for reducing salinisation then describe the salinity of thewater that will be used for the leaching process. Account for the quantities of leachingwater required and their source. Describe the recharge or replenishmentcharacteristics of the source of leaching water.
• Outline the Erosion and Sediment Control Plan to be used when constructinginfiltration ponds and clearing land for agricultural/ horticultural purposes. VegetationClearing Plan to be developed as part of EMP.
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3.2 Hydrogeology
Existing Environment
• Describe the geology and hydrogeology of the region.
• Identify all aquifers and describe their existing use.
• Describe the groundwater flow paths and water quality under existing conditions.
• Describe the characteristics of the aquifer chosen for water banking, including:
• the criteria used for selection; and• capacity of the aquifer to receive and store additional recharge.
• Identify any potential pollution sources upstream.
Potential Impacts
• Describe the changes in aquifer properties due to artificial recharge, including (but notlimited to):
• expected mixing of the treated effluent with existing groundwater and the likelywater quality changes that will occur as a consequence of mixing;
• expected chemical processes between the infiltrated waters, the nativegroundwater and the aquifer (that is the rock matrix) and likely resulting waterquality changes;
• If appropriate, use modelling to predict and illustrate changes to aquifer andresulting water quality.
• Describe the potential impact of flood events, including the management of thescheme during flooding of the Todd River.
• Describe the effects of extended residence time on recharged water quality.
• Describe the movement of groundwater in the aquifer following artificial recharge. Thisshould include a description of hydrogeological investigations and groundwatermodelling used to determine groundwater flows during scheme operation.
• Identify the potential for impact on adjacent aquifers or water sources.
• Identify the potential impacts on adjacent and downstream groundwater users, andhow they will be managed.
Safeguards
• Describe the monitoring program to be implemented. The program should includemonitoring of the following:
• quality and quantity of effluent received from the pipeline;• groundwater quality and standing water levels;• changes in water quality due to soil aquifer treatment; and• suitability of groundwater for reuse (e.g. horticulture/agriculture).
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• Describe the precautions and safeguards in the event that the effluent received fromthe Alice Springs Waste Stabilisation Ponds is of unacceptable quality, and thecontingencies in the event that contaminated water is applied to the infiltration basins.[This dot point refers to events where the Dissolved Air Flotation (DAF) plant trips ortreated effluent fails to meet acceptable criteria for injection to the aquifer]
• Contingencies for use or disposal of effluent in the event that the soil aquifer treatmentscheme cannot receive the entire supply. [This dot point refers to the situation wherethe aquifer is unable to receive the full load of treated effluent. What other disposalmethods are being considered? And how will associated impacts be managed?]
• Contingencies for treatment of effluent in the event that the DAF is unable to receiveall or part of effluent. [This dot point is seeking to clarify that only treated effluent willbe injected into the aquifer and that contingencies and/ or alternatives will be in placeto dispose of/ store effluent not treated through the DAF plant]
3.3 Heritage/ Cultural Issues
In relation to the Heritage Conservation Act and sites protected under this Act, it isrecommended that the proponent seek advice from an archaeologist on the followingmatters:
• define the precise location of heritage sites in relation to the proposal and undertakean archaeological survey;
• assess the significance of the sites which are to be impacted by the proposal;
• provide options for mitigation of loss of heritage value of sites which lie within the areaof impact; and
• undertake a further survey to ensure that other unrecorded sites, which are alsoprotected by the Act, are not included in the development area.
This section should also include the results of the inspection of the Register of Sacred Sitesmaintained by the Aboriginal Areas Protection Authority. Also, details of the applicationlodged with the Aboriginal Areas Protection Authority for an Authority Certificate within themeaning of Part 3, Division 1 of the Northern Territory Aboriginal Sacred Sites Act and acopy of the Certificate issued by the Authority as a result of that application containingconditions (if any) relating to the protection of sacred sites on, or in the vicinity of, the projectarea.
3.4 Pests
The potential for the creation of mosquito breeding sites should be addressed.
Outline weed management techniques and control of feral animals. Prepare a weedmanagement plan for inclusion in an EMP.
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3.5 Socio-Economic
Describe potential for impact to surrounding residents, particularly with regard to increasednoise from operations, use of pesticides, herbicides and inorganic fertilisers and increasedvehicle movements.
The PER is to provide information on the appropriate health standards that are to be metwhen using treated effluent for irrigation purposes (both pre and post soil aquifer treatment).Consideration needs to be given to both surrounding residents as well as workers at the AridZone Research Institute site. The PER is to outline contingency plan for when treatedeffluent does not meet appropriate standards and cannot be used for irrigation purposes.
The PER is to outline the approvals required for the proposal, including all approvals underthe Public Health Act by the Department of Health and Community Services. This should beprovided for all components of the Alice Springs Reuse Scheme (not just the subjectapplication).
3.6 Environmental Management Plan
A summary table listing potential impacts, environmental management practices andsafeguards, monitoring and management methods and other commitments, cross-referenced to the text of the report, should be provided together with the outline of an EMP.An EMP should:
• Provide details of proposed measures to prevent or minimise adverse impacts andassess the likely effectiveness of these safeguards.
• Ensure that safeguards are being effectively applied.
• Enable remedial action for any impacts that were not anticipated in the PER.
• Determine the differences between predicted and actual impacts (via monitoring); andprovide for the periodic review of the management plan itself.
An EMP will be required for both the construction and operational phases of the proposal.
Administrative Requirements
(a) 6 copies of the PER should be submitted to the Office of Environment and Heritagetogether with 2 CD-rom copies, which will provide for circulation to governmentadvisory bodies for comment. CD-rom copies should be in ADOBE®.pdf format forplacement on the Internet.
(b) Arrangements for the public display and review, including locations and number ofcopies will be made at the time when these Guidelines are finalised. It is theresponsibility of the proponent to advertise the public availability of the PER for publiccomment.
(c) The action officer for the proposal is Mr Peter Bannister (telephone 8951 9201).
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Appendix 2: Summary of Existing Water Reuse Schemes
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Location Treatment Type Prior Treatment End Use of Recycled water
Sydney water geographic area (32 treatment plants)
N/A Various - primary, high-rate primary, secondary, tertiary disinfection, chemically assisted sedimentation, microfiltration
Amenity irrigation, horticultural irrigation
Hunter Water (11 treatment plants)
N/A Various- extended aeration, oxidation ditch, trickling filter
Amenity irrigation, horticultural irrigation, power generation
Country New South Wales (57 treatment plants)
N/A Various - aerated lagoon; aerated pond, Bathurst Box, activated sludge, extended aeration, oxidation ditch, oxidation pond, Pasveer Channel, Port Macquarie Tank, trickling filter
Amenity irrigation, horticultural irrigation, power generation, mining, pasture irrigation, agricultural experiment
Victoria (112 treatment plants)
N/A Various - aerated lagoon, extended aeration, biological nutrient removal, activated sludge, extended aeration, high rate oxidation lagoon, high rate trickling filter, Imhoff, oxidation lagoon, Pasveer Channel, trickling filter
Amenity irrigation, horticultural irrigation, mining, pasture irrigation, nursery operations, recreation, washdown areas, floriculture
Queensland (79 treatment plants)
N/A Various - aerated lagoon, extended aeration, biological nutrient removal, activated sludge, extended aeration, high rate oxidation lagoon, high rate trickling filter, Imhoff, oxidation lagoon, Pasveer Channel, trickling filter
Amenity irrigation, horticultural irrigation, power generation, mining, pasture irrigation, oil refining, recreation, vehicle washdown areas, dust suppression
South Australia (13 treatment plants)
N/A Various - integrated fixed-film activated sludge, activated sludge, dissolved air floatation & filtration, aerated lagoon, oxidation ditch, oxidation pond
Amenity irrigation, horticultural irrigation (particularly grapes)
Western Australia (43 treatment plants)
N/A aerated pond, aerated pond with Alum dosing, oxidation pond, activated sludge
Amenity irrigation, horticultural irrigation, mining, revegetation, industrial, beef production
Tasmania (30 treatment plants)
N/A Secondary and tertiary Amenity irrigation, horticultural irrigation, dairy production.
Australian Capital Territory (2 treatment plants)
N/A Oxidation pond, activated sludge
Amenity irrigation, horticultural irrigation
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Location Treatment Type Prior Treatment End Use of Recycled water
Northern Territory (8 treatment plants)
N/A Activated sludge, dissolved air floatation & filtration, oxidation pond
Amenity irrigation, horticultural irrigation, beef cattle production
Tucson, Arizona 8 infiltration basins and 2 wetlands
Secondary effluent and filtered secondary effluent.
Amenity irrigation
Tres Rios Cobble Site, Phoenix, Arizona
2 wetland basins Nitrified/denitrified effluent Not stated
San Gabriel Spreading grounds Los Angeles County
Infiltration basins Tertiary effluent (primary sedimentation, aeration with activated sludge, secondary sedimentation, prechlorination, filtration, post-chlorination and dechlorination)
Groundwater recharge
Mesa Northwest Water Reclamation Plant, AZ - City of Mesa
4 basins Tertiary effluent (primary sedimentation, biological nitrification/denitrification, secondary clarification, chlorination, tertiary filtration, and dechlorination)
Amenity irrigation/ groundwater recharge
Rio Hondo Spreading Grounds, Los Angeles County
Infiltration basins Tertiary effluent (primary sedimentation, aeration with activated sludge, secondary sedimentation, prechlorination, filtration, post-chlorination and dechlorination)
Groundwater recharge
Hansen Spreading Grounds, Los Angeles
Infiltration basins Tertiary effluent (primary sedimentation, aeration with activated sludge, secondary sedimentation, prechlorination, filtration, post-chlorination and dechlorination)
Groundwater recharge
Sierra Vista, Southern Arizona
11 basins Not stated Groundwater recharge
Prescott, Arizona 8 cells Not stated Amenity irrigation/ Groundwater recharge
City of Goodyear, Phoenix, Arizona
6 basins Not stated Groundwater recharge/ Dust control
Town of Gilbert, Phoenix, Arizona (Water Ranch)
7 basins Tertiary treatment Amenity irrigation/ Groundwater recharge/ supply artificial lakes
Town of Gilbert, Phoenix, Arizona
Not stated Secondary treatment Amenity irrigation/ Groundwater
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Location Treatment Type Prior Treatment End Use of Recycled water
(Neely Ranch) recharge/ supply artificial lakes
City of Peoria, Phoenix, Arizona
9 basins Secondary treatment Groundwater recharge
Israel (237 projects nationally, including larger programmes such as Kishon at Haifa and the Dan Project at Tel Aviv and )
At Haifa, storage in above ground reservoirs At Dan Project, groundwater recharge (SAT)
At Haifa, Tertiary treatment including chlorination At Dan project, tertiary treatment including disinfection, storage in aquifer
In general, 30% of recycled water collected used for groundwater recharge, 42% used for irrigation Haifa water used for cotton irrigation (unrestricted use) At Dan project, unrestricted use for irrigating crops eaten raw
Campo Espejo, Argentina
N/A Primary treatment Irrigation of land
Ortega, Argentina N/A Secondary treatment through use of stabilisation pond
Unrestricted irrigation of vegetable crops (note – this practice was seen as posing risk to human health)
Sao Paulo, Brazil N/A Tertiary treatment, including coagulation, filtration and disinfection
Industrial use, but range of other non-drinking water uses proposed
Santiago, Chile N/A Primary treatment Irrigation of horticultural crops
Cyprus Proposed storage, but not specified if in groundwater aquifer
Tertiary treatment including filtration and disinfection
Agricultural irrigation in dry weather
Kuwait N/A Tertiary treatment, including activated sludge treatment, disinfection and filtration
Agricultural irrigation
Saudi Arabia, committed to a policy of complete reuse
N/A Various depending on final use, but as strict as US and Australian Guidelines
Range of uses, including irrigation, industry and non-potable house-hold use
United Arab Emirates
N/A Tertiary treatment, including, disinfection by chlorination and ozonation and sand filtration
Urban and agricultural irrigation
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Appendix 3: Summary of Community Consultation
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Date Item August 2000 Public Forum to discuss water usage issues in Alice Springs, called the
Urban Water Management Strategy August 2000 Community discussion paper on water management in Alice Springs
released September 2000 ASUWMS release community newsletter 1 July 2001 ASUWMS release community newsletter 2 09 August 2001 Interview about scheme on ABC Radio Drive Time 10 May 2002 Workshop to develop tsargets and actions in response to water
management issues in Alice Springs 20 August 2002 ABC radio interview with local residents about a public meeting that
outlined the ‘Water Reuse in the Alice’ project. Residents were pleased the project was happening.
28 August 2002 Power and Water issue media release about ‘pulse’ into St Mary’s Creek commencing
13 November 2002 Imparja news story on Ilparpa Swamp rehabilitation plans January 2003 Aquifer Storage and Recovery Workshop 15 January 2003 Power and Water and ALEC speak to ABC about mosquito numbers at
Ilparpa due to algae breakout April 2003 Poster on Horticulture April 2003 Poster on Monitoring in the Ponds April 2003 Poster on Testing Water Quality 28 April 2003 Water Reuse Scheme launched by DR Chris Burns at WTP 28 April 2003 Letter to local residents in proximity to AZRI 28 April 2003 Media Release about Ilparpa Swamp 29 April 2003 Overview article on scheme in Rural Review newsletter 7 May 2003 Interview about environmental issues at Ilparpa Swamp on ABC Radio
Drive Time 23 May 2003 Power and Water web page article on Water Reuse in the Alice 01 June 2003 Marnie Ireland attended Rural Areas Association meeting to hear
concerns and outline proposal. 04 June 2003 Internal Update newsletter to NTG Project Team 18 June 2003 Article on scheme in Alice Springs News 20 June 2003 Overview presentation to Alice Springs Rangelands Ecology and
Biology Technical Group 21 June 2003 Site tour at AZRI for residents 22 June 2003 Overview presentation to Rural Areas Association 23 June 2003 Interview with ABC Radio Country Hour 23 June 2003 Interview with ABC Radio Country Hour 27 June 2003 Overview presentation to DBIRD Alice Springs staff 30 June 2003 Overview presentation to Alice Springs Town Council 01 July 2003 Overview presentation to John Baskerville 08 July 2003 Overview presentation to Andrea Martin & John Elferink
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15 July 2003 Internal Update newsletter to NTG Project Team 18 July 2003 Story on Water Reuse Scheme on Imparja television 18 July 2003 Overview presentation and site tour with local media 20 July 2003 Overview presentation, discussion and site tour / open day with local
residents 22 July 2003 Story on scheme aired on Imparja Television news 22 July 2003 Interview with ABC Radio Country Hour 25 July 2003 Article on scheme in Centralian Advocate 28 July 2003 Presentation of key elements of scheme to Power and Water
Environment Committee 01 August 2003 Internal Update newsletter to NTG Project Team 08 August 2003 Interview with ABC Radio Country Hour 13 August 2003 Overview presentation to Blatherskite Park Trustees 20 August 2003 Article on horticultural development aspects of scheme in Alice Springs
News print media 01 September 2003 Technical presentation of scheme at 2nd National Water Recycling
Conference in Brisbane 15 September 2003 Article on scheme in Northern Territory News print media 26 September 2003 Stakeholder Update and FAQs sent to external stakeholders 02 October 2003 Interview on progress of scheme with ABC Radio Country Hour 06 October 2003 Internal Update newsletter to NTG Project Team 10 October 2003 Overview on ABS Radio Country Hour 14 October 2003 Community Forum held at Witchetty’s – Araluen Arts Centre, Alice
Springs 16 October 2003 Media Release on scheme from Office of Chief Minister 17 October 2003 Article on scheme in Centralian Advocate 30 October 2003 Water open Day at WTP 24 March 2004 Presentation on scheme at Australian Wastewater and Recycling
Forum 12 April 2004 Article on scheme in Alice Springs News 14 May 2004 Article on scheme in Centralian Advocate 14 July 2004 Article on scheme in Alice Springs News 15 July 2004 Advertisements for Water Reuse Open Day at AZRI on local radio 8HA
and SunFM 16 July 2004 Advertisement for Water Reuse Open Day at AZRI in Centralian
Advocate 16 July 2004 Radio interviews on 8HA Breakfast, SunFM and ABC Radio Breakfast
Show 17 July 2004 Water Reuse Open Day at AZRI 20 July 2004 Radio interview on ABC Country Hour 21 July 2004 Article on scheme in Alice Springs News October 2004 Poster on Rehabilitating Ilparpa Swamp on display in local shopping
centres
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October 2004 Poster on Soil Aquifer Treatment on display in local shopping centres October 2004 Poster on Water Quality and Treatment on display in local shopping
centres October 2004 Poster on Project Timeline on display in local shopping centres October 2004 Fact Sheet on Alice Springs Water Reuse Scheme on display in local
shopping centres and in public places October 2004 Fact Sheet on Soil Aquifer Treatment on display in local shopping
centres and in public places October 2004 Fact Sheet on making the most of precious water resources on display
in local shopping centres and in public places October 2004 Fact Sheet on Water Reuse in the Alice on display in local shopping
centres and in public places October 2004 Fact Sheet on Water Recycling in Australia on display in local shopping
centres and in public places October 2004 Fact Sheet on Groundwater Basics on display in local shopping
centres and in public places October 2004 Fact Sheet on what can be grown with recycled water in Alice Springs
on display in local shopping centres and in public places October 2004 Fact Sheet with glossary of terms used in Alice Springs Water Reuse
Scheme on display in local shopping centres and in public places October 2004 Fact Sheet on Soil Aquifer Treatment and Water banking on display in
local shopping centres and in public places October 2004 Fact Sheet on Frequently Asked Questions on display in local
shopping centres and in public places 02 November 2004 Public Presentation on Soil Aquifer Treatment at AZRI 23 November 2004 Letter drop to local residents advising of public forum 23 November 2004 Public forum advertised in print media 30 November 2004 Public Forum on PER, focussing on PER process and issues 7 February 2005 Letter drop to local residents advising of public forum 7 February 2005 Public forum advertised in print media 14 February 2005 Radio interview on scheme on ABC radio Drive Time 14 February 2005 Public Forum on PER, focussing on issues and management
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Appendix 4: AS: 4360 (1999) Risk Management
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Risk assessment based on AS4360:1999 combines (qualitative) estimates of the likelihood of a certain event or environmental impact occurring and the consequence. The risk assessment allows potential impacts to be prioritised in terms of their significance. The likelihood rankings, from least to most likely, are as follows: • Rare - the event may occur only in exceptional circumstances; • Unlikely - the event could occur at some time; • Moderate - the event should occur at some time; • Likely - the event will probably occur in most circumstances; and • Almost certain - the event is expected to occur in most circumstances. The consequence rankings, from smallest to greatest, are as follows: • Insignificant - no environmental harm; • Minor - insignificant environmental harm; • Moderate - minor environmental harm; • Major - substantial environmental harm; and • Catastrophic - high degree of environmental harm. An assessment of the overall risks associated with events or activities is then made, based on the perceived likelihood of an event occurring and the potential realistic worst case effects associated with the event. The table below shows how the combination of likelihood and consequence is used to determine the overall significance rating.
Consequence (or Impact) Likelihood Insignificant Minor Moderate Major Catastrophic
Almost certain
High High Extreme Extreme Extreme
Likely
Medium High High Extreme Extreme
Moderate
Low Medium High Extreme Extreme
Unlikely
Low Low Medium High Extreme
Rare
Low Low Medium High High
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The risk rankings in the table above determine the degree of management required to mitigate the impact and are defined as follows: • Extreme – immediate action required; • High – senior management attention required; • Moderate – management responsibility can be delegated; and • Low – management by routine procedures.
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Appendix 5: Summary of Alice Springs Geology and Groundwater Resources
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GeologicalFormations
General Description Groundwater Resources Recharge Sources/Discharge Areas Water Quality Beneficial Use Recycled water ASR SuitabilityNon-Drinking Water Quality
Potential Impacts fromProposedSAT/Horticulture Schemes
Arunta Complex Geological RegionNear Surface Weathered ZoneVery localised and limitedgroundwater storage associatedwith fracturing. Boreholeextraction rates generally lessthan 1 L/s.
Predominantly direct rainfall infiltrationon surface outcrops or contact withoverlying recent sedimentsassociated with the Todd River.Similar discharge to recent sedimentsmay also occur.
Good to saline dependingupon proximity to rechargesources associated withrainfall or overlying alluvialdeposits.
Limited localised extraction byrural properties around AliceSprings primarily for irrigationuse in areas with suitablerecharge of low salinity water(i.e. adjacent to surfacedrainage features).
Not suitable due to limited andvariable permeability restrictingaquifer recharge or subsequentextraction.
None anticipated due toelevated and isolated natureof suitable recharge zoneslocated up gradient of boththe Blatherskite andHeavitree Gaps.
Arunta Block Bedrock Comprising predominantlyhard, fresh metamorphic gneiss andschist with intrusions of igneousgranite and various dykes.Generally present on a massivescale and fresh at depth.Weathering effects occur atexposed surfaces and below formererosion surfaces now covered bymore recent sediments.
Fresh Rock at DepthNegligible groundwater presentwithin low permeability rock.
Recharge likely to be relatively smallin comparison with overall size of rockformation and sourced from contactwith overlying alluvial, colluvial orother recent sediments associatedwith the Todd River
Formation groundwater isnaturally saline
None identified. Not suitable due to limited andvariable permeability restrictingaquifer recharge or subsequentextraction
None anticipated due thepresence overlying AmadeusBasin and Tertiary AgeSediments preventing SATscheme groundwatermigration.
Tertiary AgeSediments
Semi-consolidated beds of clay,sandy clay and sands with amaximum total thickness of 50 muncomformably overlying the AruntaBlock. Only present in localisedareas between the Heavitree andBlatherskite Ranges with maximumindividual bed thicknesses of 3 m.Considered to have been depositedwithin a lake or stream environmentfollowing erosion of the AruntaComplex and Amadeus Basin.These sediments also includecolluvial deposits present on theformer erosion surface of the AruntaBlock prior to deposition of theTertiary Age material.
Comprises both Semi-confinedaquifers limited to localised, non-continuous sand beds less than 3m thick and colluvial depositslocated along the contact betweenthe Arunta Block and more recentsediments. Borehole extractionrates generally less than 5 L/s.
Recharge is primarily sourced fromcontact with overlying alluvialsediments associated with the ToddRiver south of Heavitree Gap. Mayalso occur through leakage from thewastewater treatment ponds and theirrigation of Blatherskite Park and theTree Lot.Discharge would generally be limitedby existing extraction. Any excesswater would generally need to re-enter overlying alluvial sedimentsprior to discharge through BlatherskiteGap.
Good to saline dependingupon proximity to rechargesources associated withoverlying alluvial deposits.
Limited to localised extractionwithin the Commonage Area ofthe Inner Farm Basin forirrigation use where rechargeof low salinity water readilyoccurs.
Not suitable due to presence ofunacceptably high groundwaterlevels within the Inner FarmBasin resulting from ongoingexisting artificial rechargeoccurring from the wastewaterponds and irrigation systems.
Impacts possible throughincreased groundwaterlevels within the Outer FarmBasin restricting existingdischarge of groundwaterfrom the Inner Farm throughBlatherskite Gap. This effectcould further increasegroundwater levels or lowerthe naturally occurringdischarge of relatively salinewater from within the InnerFarm Basin.
Town Basin Unconsolidated alluvial depositscomprising sands, silts, clays andgravels resulting from past andpresent deposition and erosion ofsediments associated with waterflow within the Todd River north ofHeavitree Gap. Alluvial sedimentsdirectly overlie the Arunta Blockformation and colluvial depositspresent prior to the deposition of theTown Basin. For the purposes ofthis report the alluvial and colluvialsediments are considered tocomprise a single groundwaterresource. The deepest area ofalluvial sediments is withinHeavitree Gap.
Comprises a series of non-continuous, interconnectedunconfined and semi-confinedaquifers in sand and gravelsediments present below thecurrent alignment of the ToddRiver and infilled formeralignments in the form ofpalaeochannels. Until the late1960s, the Town basin providedall of the Alice Springs towndrinking water supply. Useceased due to overuse resulting indepletion of the groundwaterresource. Use recommenced inthe 1970s for irrigating variouspublic open spaces following asignificant increase ingroundwater levels and salinity.At present the Town Basinprovides approximately 800 ML/yfor such purposes.
Key recharge source is water flowwithin the Todd River followingsignificant rainfall. Strong correlationshave been documented betweenrainfall and almost immediateincrease in groundwater levels withinthe Town Basin. This rechargesource is estimated to provide onaverage approximately 600 ML/y.Remaining recharge sourcescomprises seepage from parks andgarden irrigation within Alice Springsusing water sourced from the RoeCreek Borefield and ongoing leakagefrom water and sewer pipelinesystems.Significant groundwater dischargefrom the Town Basin occurs from theTown Basin to the Inner Farm Basinthrough Heavitree Gap.
Salinity levels vary in withproximity to the Todd Riverthat provides high qualityrecharge, the proximity toHeavitree Gap where allgroundwater mixes prior todischarge and the variation ingroundwater levels that resultin contact with near surfacesaline soils. Prior to stoppinggroundwater extraction in the1960s the Town Basingenerally provided goodquality water. Since this timethe water quality hasdeteriorated through risinggroundwater levels contactingsaline soils and ongoingcollection of salts throughirrigation from the Roe CreekBorefield.
Induced salinisation ofgroundwater currently restrictsthe beneficial use of the TownBasin to irrigation use.Ongoing management of theTown Basin such asmaintaining lower groundwaterlevels may reduce salinitylevels to support otherBeneficial Uses over time.
Not suitable due to presence ofunacceptably high groundwaterlevels within the Town basinresulting from artificial rechargefrom irrigation and water andsewer pipe leakage.
Groundwater flow gradientsacross both the Blatherskiteand Heavitree Gaps willprevent any migration ofpotential groundwatercontaminants. Key potentialrisk is increasedgroundwater levels within theOuter Farm Basindecreasing groundwaterdischarge rates of the TownBasin into the Inner FarmBasin. Any such decrease indischarge may increasegroundwater levels within theTown Basin and impact uponongoing salinityconcentrations.
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GeologicalFormations
General Description Groundwater Resources Recharge Sources/Discharge Areas Water Quality Beneficial Use Recycled water ASR SuitabilityNon-Drinking Water Quality
Potential Impacts fromProposedSAT/Horticulture Schemes
Inner FarmBasin
Geological conditions are generallysimilar to the Town Basin, exceptthat the main, higher permeability,palaeochannel groundwater flowpaths are generally restricted to theimmediate area adjacent to theexisting Todd River Alignment. Thedeepest section of the Inner FarmBasin alluvial sedimentsapproximately 30 m, located withinBlatherskite Gap that historicallywas the alignment for the ToddRiver.
The Groundwater resourceconditions are similar to the TownBasin on a smaller scale. TheInner Farm Basin has primarilybeen used for non-drinkingpurposes, except for a shortperiod to supplement the AliceSprings drinking water supply inthe 1960s until the full introductionof the Roe Creek Borefield. Boreextraction rates are generallylimited to less than 5 L/s, althoughtargeted and properly constructedbores have recently achievedextraction rates up to 15 to 20 L/s.Ongoing irrigation, leakage fromthe wastewater treatment pondsand seepage from overflow toIlparpa Swamp have considerablyincreased groundwater levelswithin the Inner Farm Basin.Following significant rainfallevents groundwater levels havebeen recorded just below thegroundwater surface.
Aquifer Recharge comprises acombination of significant flows in theTodd River, discharge from the TownBasin through Heavitree Gap, variousirrigation sources, wastewater pondleakage and Ilparpa Swamp seepage.Estimates of annual recharge to theInner Farm Basin range between 600Ml/year to 1,500 ML/year.Groundwater discharge is primarilythough Blatherskite Gap into theOuter Farm Basin alluvial sedimentswithin the Amadeus Basin.
As with the Town Basin,groundwater quality hasdecreased through varioussalinisation processes.Water quality is also likely tobe impacted to some degreeby the presence of thewastewater ponds andoverflow seepage to IlparpaSwamp.
Similar to the Town Basin. Not suitable due to presence ofunacceptably high groundwaterlevels within the Inner Farmbasin resulting from artificialrecharge from irrigationwastewater ponds and IlparpaSwamp.Further increase in groundwaterlevels within the Inner FarmBasin may also decreasegroundwater discharge from theTown basin through HeavitreeGap.
Groundwater qualityproduced by the SATscheme is likely to be ofbetter quality than theexisting recharge of the InnerFarm Basin from thewastewater ponds andIlparpa Swamp.As with the Town Basin, thekey concern would beincreased groundwaterlevels within the Outer Farmbasin decreasing thegroundwater gradient withthe Inner Farm Basin andtherefore impactinggroundwater levels andsalinity in both the InnerFarm and Town Basins.
Amadeus Basin Geological Region
HeavitreeQuartzite
Hard quartz sandstone bandapproximately 150 m thick with thininterbedding of shale. Steeplydipping around Alice Springs asdemonstrated by outcrops formingthe Blatherskite and HeavitreeRanges. The Heavitree Quartzitesits uncomfortably on the AruntaBlock. Along with the Bitter SpringsLimestone this rock formationeffectively marks the boundarybetween the Arunta Complex andthe younger Amadeus Basin.
Localised supply near surface inrock fractures. Non existent atdepth
Localised recharge from rainfall andsurface flows within highly fracturedzones near the surface.Discharge following significant rainfallevents would be within alluvialaquifers or at ground level near thechange in gradient from the varioussteep ranges to the surroundingplains.
Generally brackish to salineexcept where localisedrecharge from the Todd Riveroccurs where good qualitywater may be obtained.
Limited to minor localised non-drinking water supplies in thearea adjacent to Heavitree andBlatherskite Gaps.
Not suitable due to limitedpermeability and storagerestricting aquifer recharge orsubsequent extraction.
None identified due tonegligible beneficial use.
BitterSpringsLimestone
Approximately 800 m thicksequence of hard limestone withinterbedded sequences of shale andsiltstone. Within the near-surfaceweathering zone, this formationcontains solution cavities andfactures containing groundwater. Atdepth groundwater is limited toprimary permeability withinindividual rock beds. Liesconformably over HeavitreeLimestone, with similar steep diptowards the south near AliceSprings.
Generally limited to near surfacefractures and solution cavities withbore extraction rates up to 10 L/s.Considerable decrease ingroundwater resource occurs withdepth.
Recharge results primarily fromsignificant rainfall events throughcontacts with alluvial sedimentsassociated with the Todd River andRoe Creek and fractured zones withinthe Heavitree Quartzite. May alsoreceive some consistent groundwaterflow from the underlying Arunta Block.Discharge is not well understood butwould occur through a range ofcontracts with younger overlying rockbeds and more recent Tertiary Ageand alluvial unconsolidatedsediments.
Generally brackish to saline,particularly at depth, exceptwhere good quality rechargeoccurs from near surfacecontact with the HeavitreeQuartzite and overlying alluvialsediments.
Limited to localised non-drinking water supplies wherenear surface fractures andsolution cavities are rechargedfollowing significant rainfallevents.
Limited feasibility due togenerally low permeability andstorage and existing relativelyhigh groundwater salinity.Possible use was alsodiscounted due to the potentialfor increased groundwaterdischarge into overlying alluvialsediments near Blatherskite Gapmay impact upon existinggroundwater discharge requiredto manage groundwater levelswithin the Inner Farm Basinrequired.
Limited potential for impactupon shallow non-drinkingwater use due to existinggroundwater gradients andflow regimes that shouldprevent flow from the AZRIsite. Issues would only beanticipated to arise in theevent that groundwaterlevels within the Outer FarmBasin were increasedsignificantly (i.e. near thesurface).
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GeologicalFormations
General Description Groundwater Resources Recharge Sources/Discharge Areas Water Quality Beneficial Use Recycled water ASR SuitabilityNon-Drinking Water Quality
Potential Impacts fromProposedSAT/Horticulture Schemes
PioneerSandstonePertatakaSiltstoneJulieFormationArumberaSandstoneHugh RiverShales
Overlying the Bitter SpringsLimestone are a series ofsedimentary formations comprising,sandstone, siltstone, shale,conglomerate and limestone with atotal thickness of approximately 500m.Knowledge of these formations isand associated groundwatersystems generally limited as theyare considered of little value from agroundwater resource perspective.The Arumbera Sandstone is theonly formation with a significantsurface outcrop within the AliceSprings area shown on Figure X4.
Generally limited to fracturedzones present within hardersandstone formations or withinweathering profiles of softer orfiner grained rocks.Groundwater bore supplies aregenerally less than 2 L/sec.
Groundwater regime within theseformations not well understood.Studies completed for the Roe Creekbore field have identified that surfacewater flows along rivers and creeksare a key source of recharge for rockformations within the Amadeus Basinwhere they intersect overlying alluvialsediments adjacent to large drainagesystems.Some recharge and discharge fromgroundwater movement acrossboundaries with overlying andunderlying sediment and rockformations would also be anticipated.
Groundwater present withineach of these formation isgenerally saline except wheregood quality recharge occursfrom contact with near surfacealluvial sediments or theadjacent Shannon Formationat depth.
Limited to minor localised non-drinking water supplies infractured sandstone adjacentto near-surface alluvialsediments or the ShannonFormation at depth.
Limited feasibility due togenerally low permeability andstorage and existing relativelyhigh groundwater salinity. Wasalso not considered as thecurrent knowledge ongroundwater conditions presentwithin these formations is notwell understood.
None identified due to limitedbeneficial use and theabsence of suitablegroundwater migrationpathways from the AZRI siteto these formations bothvertically (at least 80 m oflow permeability clay) andhorizontally (a distance ofseveral kilometres upgradient).
ShannonFormationJay CreekLimestone
For the purposes of this report theseformations are considered to be thesame geological unit.With a total thickness ofapproximately 1,200 m, thisformation comprises a lowersequence of siltstone overlain by anupper layer of limestone. Within thearea of the Roe Creek Borefield thelimestone is approximately 350 mthick and ranges between 150 mand 1,000 m thick elsewhere, isquite fractured and containsextensive solution cavities.This formation contains oneproduction bore (3% of total volume)for the Alice Springs drinking watersupply.
The Shannon formation is animportant groundwater resourceas identified by its use in the RoeCreek Borefield. The single boreproduces approximately 40 L/secwith a long term drawdown of 70m. Overall groundwatermovement is from west to east.Ongoing use of this aquifer has,however, resulted in a large deepcone of depression that can bemeasured a considerable distancefrom the Roe Creek Borefieldtowards Alice Springs.
As noted for the formations above,the key source of recharge isconsidered to be water flow within theTodd River and Roe Creek andassociated alluvial sediments.As above, Some recharge anddischarge from groundwatermovement across boundaries withoverlying and underlying sedimentand rock formations would also beanticipated.Recharge is considered to beindependent of individual rainfall orriver flow events, with average age ofgroundwater within the Roe CreekBorefield typically 10,000 to 12,000years.
At the depth of currentgroundwater extractiongroundwater quality is goodand used for drinking watersupply. It is know that waterquality decreases within depthto saline. The zone of goodquality water reflects the zoneof influence from rechargesources associated with theTodd River and Roe Creek.
The current beneficial use ofthe upper section of thisformation is drinking water,although a much lower yieldthan other formations presentat the Roe Creek Borefield. Itis anticipated that thegroundwater resource will bemanaged to maintain thisbeneficial use into the future.At greater depth the beneficialuse reduces as salinity levelsincrease.
This geological unit wasselected as the preferredformation for further studies forintroduction of aquifer storageand recovery to manage excesswastewater flow from AliceSprings (SKM, 2000a).Suitability is limited by currentuse for drinking water supplyand some uncertainty with thelong term performance of thisaquifer system.
Potential impacts consideredto be low due to absence ofdirect groundwater migrationpathways from the AZRI siteto these formations bothvertically (at least 80 m oflow permeability clay) andhorizontally (a distance ofseveral kilometres).Detailed monitoring at theRoe Creek Borefield hasidentified no impact ingroundwater levels within theoverlying Tertiary sedimentseven through extraction hasbeen undertaken for 40years and groundwaterlevels wihin the underlyingrock have decreased by upto 50 m.
GoyderFormation
Overlying the Shannon Formation,the Goyder Formation comprisesalternating soft and weaksequences of sandstone andsiltstone with a total thickness ofapproximately 300 m.This formation is considered to actas a semi-confining layer togroundwater movement betweenthe underlying Shannon Formationand the younger overlying ParcootaSandstone.
Overall, this formation is notconsidered a significant groundwater resource compared toadjacent formations. Locally,however this formation canprovide reasonable ground waterquantities for extraction.
Refer Shannon Formation above. Refer Shannon Formationabove.
Refer Shannon Formationabove.
Limited feasibility due toalternating sequences of lowerpermeability siltstone and theimmediate proximity to theoverlying Parcoota Sandstoneused for drinking water supplies.
Refer Shannon Formationabove.
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GeologicalFormations
General Description Groundwater Resources Recharge Sources/Discharge Areas Water Quality Beneficial Use Recycled water ASR SuitabilityNon-Drinking Water Quality
Potential Impacts fromProposedSAT/Horticulture Schemes
ParcootaSandstone
Overlying the Goyder Sandstone,this formation contains two distinctsandstone units separated bysiltstone, mudstone and shale withan overall thickness of 350 m to450 m.This formation contains threeproduction bores (22% of totalvolume) for the Alice Springsdrinking water supply.
Similar groundwater resourceconditions to the ShannonFormation.
Refer Shannon Formation above. High quality groundwatersuitable for drinking waterpurposes. Generally betterwater quality than other aquiferformations.
Refer Shannon Formationabove.
Limited feasibility due toimportance of this formation tothe drinking water supply toAlice Springs.
Refer Shannon Formationabove.
MereenieSandstone
The Mereenie Sandstone is the keyformation in the Amadeus Basinnear Alice Springs in terms ofgroundwater supply. With anoverall thickness of approximately365 m, it is commonly divided into aseries of subunits. It generallycomprises clean, very poroussandstone that is highly fractured insome subunits that provides aconsiderable increase ingroundwater movement.The formation contains sixteenproduction bores (75% of totalvolume) for the Alice Springsdrinking water supply.
This formation is a very importantgroundwater resource, both locallyand on a regional scale. It isconsidered the main groundwatermovement pathway from west toeast within the northern AmadeusBasin.Overuse of this formation by anorder of magnitude compared toestimated natural recharge hascreated a 50 m deep drawdowncone that extends to AliceSprings, approximately 10 kmaway.
Refer Shannon Formation above. Refer Parcoota Sandstoneabove.
Refer Shannon Formationabove.
Refer Parcoota Sandstoneabove.
Refer Shannon Formationabove.
HermannsburgSandstone
The Hermannsberg Sandstone isapproximately 600 m thick andunconformably overlies both theMereenie and Parcoota Sandstoneformations. The formation containsinterbedded sequences of siltstoneand is considered to be difficult todistinguish from the MereenieSandstone formation.
This formation is generallyconsidered to be low yielding (<1L/sec) and only suitable for localcommunity supplies. Somevariation does exist. Relativelyhigh yielding bores have beenconstructed in the formation nearAlice Springs. At the Roe CreekBorefield this formation isgenerally too shallow to besaturated.
Refer Shannon Formation above. Refer Shannon Formationabove.
Refer Shannon Formationabove.
Limited feasibility due toalternating sequences of lowerpermeability siltstone and theimmediate proximity to theunderlying Mereenie Sandstoneused for drinking water supplies.
Refer Shannon Formationabove.
PertnjaraSiltstone
The Pertjara Siltstone is the mostmassive and widespread of theAmadeus Basin Formations.Overlaying the other formations itgenerally comprises siltstone withsome sandstone beds and havebeen identified up to severalkilometres thick.
This formation is generallyconsidered to be low yielding (<1L/sec) and only suitable for localcommunity supplies.
Limited feasibility due toalternating sequences of lowerpermeability siltstone.
Potential impacts areconsidered to be low due toabsence of directgroundwater migrationpathways from the AZRI siteto these formations bothvertically (at least 80 m oflow permeability clay) andhorizontally (a distance ofseveral kilometres).
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GeologicalFormations
General Description Groundwater Resources Recharge Sources/Discharge Areas Water Quality Beneficial Use Recycled water ASR SuitabilityNon-Drinking Water Quality
Potential Impacts fromProposedSAT/Horticulture Schemes
Tertiary AgeSediments
Semi-consolidated beds of clay,sandy clay and sands with awidespread presence within theAmadeus Basin overlying formererosion surfaces of the much olderrock formations described above.Below the AZRI site the thickness ofthe Tertiary sediments variesbetween 80 m and 300 m.The predominant composition of theTertiary sediments is clays andsandy clays. Near Alice Springsand below the AZRI site the TertiarySediments are know to contain upto four semi-continuous lenses ofsand no more than 2 m thickranging in depth between 50 m and100 m.
Groundwater resources within theTertiary sediments are generallylimited to the semi-continuouslenses of sand present throughoutthis formation.Within and adjacent to the AZRIsite four such lenses containingrecoverable groundwater havebeen identified, with boreextraction rates up to 7 L/sec.The sand lenses are consideredto be confined. Investigations atthe AZRI site have identified anupper sand lense at a depth ofapproximately 50 m, with astanding water level of only 18 m(i.e. a pressure head of 32 m).
Limited studies on the TertiarySediments indicate that near AliceSprings the key recharge source forthe sand lenses within the TertiarySediments is likely to be throughdirect contact with upper layers of theBitter Springs formation and somehydraulic connection to overlyingalluvial sediments and the ToddRiver.Discharge from the Tertiary sandlenses is not well understood,however it is considered possible thatthe pressure head within the confinedsand lenses may be sufficient toresult in upwards migration intooverlying alluvial sediments.
Water quality found within thesand lenses variesconsiderably but generally onlyfair to poor and deterioratingover time. Salinity levels of1,000 mg/L to 1,500 mg/L aretypical.
Current beneficial use isconsidered to be non-drinkingwater. A series of extractionbores located within the AZRIsite and adjacent residentialproperties utilise the Tertiaryaquifers for commercial anddomestic irrigation purposes.
Limited feasibility due to small,non-continuous nature of thesand lenses and existingsaturation and high pressurehead that would not allowadditional storage for artificialrecharge.
The SAT scheme does havethe potential to impact uponthis aquifer system throughpossible migration pathwaysfrom overlying alluvialsediments. The risk fromsuch migration is likely to below given the existing highpressure gradient upwardsbetween the TertiarySediments and overlyingalluvium.Of greater concern are old orpoorly constructionextraction bores presentwithin the AZRI site andsurrounding properties thatmay short circuit naturalgroundwater movementpathways. Such potentialcross-connections havebeen documented within theAZRI site and identified as apossible source forincreasing salinity levelswithin the upper Tertiarysand lenses.
Outer FarmBasin
Quaternary age unconsolidatedalluvial deposits comprising sands,silts, clays and gravels associatedwith past and present flow channelsof the Todd River and overflow ofthe surrounding open plain.Located south of BlatherskiteRange, the quaternary sedimentsprimarily overlie the Tertiary AgeSediments, except adjacent tooutcrops of Amadeus Basin rockand form the Outer Farm Basin.A semi-linear palaeochannel featurecontaining the deepest extent of thealluvial sediments incised intounderlying Tertiary sediments hasbeen identified that extends fromHeavitree Gap, through the InnerFarm Basin, Blatherskite Gap andinto the AZRI site from the northernboundary to the south east cornerwith Colonel Rose Drive andadjacent residential properties.The nature and extent of thepalaeochannel feature beyond theAZRI site is not well understood atpresent.
The Outer Farm Basin is currentlyconsidered to provide anunreliable groundwater resourceon the basis that water levels andsalinity are highly variable withtime.Investigation information indicatesthat the main aquifer would be a10 m thick gravel layer presentwithin the identifiedpalaeochannel. The investigationinformation suggests that thegravel may be semi confined by awidespread layer of clay and silt.Anecdotal experience withgroundwater resources in theInner Farm Basin and Town Basinsuggest that in practice the alluvialsediments within thepalaeochannel and surroundingarea effectively act as a singleunconfined aquifer.
The predominant recharge source ofthe Outer Farm Basin is water flow inthe Todd River following significantrainfall events. Other rechargesources include the Inner Farm basinthrough Blatherskite Gap and directrainfall and irrigation over the area ofthe Outer Farm Basin.Groundwater level monitoringindicates that the preferredgroundwater flow pathway is alongthe main palaeochannel feature fromBlatherskite Gap and through theAZRI site.The discharge point for groundwaterwithin the Outer Farm Basin beyondthe AZRI site is not currently known.It is assumed that it continues to thesouth east reconnecting the ToddRiver alignment further downgradient.
Salinity levels within the OuterFarm Basin vary greatly butare generally considered to bepoor (1,500 mg/L to 3,000mg/L).
The Outer Farm Basingroundwater resourcescurrently have no beneficialuse due to unreliablevariations in water levels andsalinity.
Preliminary studies (SKM2000a) discounted use of thepalaeochannel feature for ASRon the basis thathydrogeological properties werenot well understood at the time.Subsequent investigations,modelling and preliminaryrecharge trials have indicatedthat artificial recharge of thepalaeochannel through the useinfiltrations could be practical.
One of the key features ofthe Outer Farm Basin is thegeneral absence of hydraulicconnections with the othergroundwater resources in theAlice Springs. There is a lowrisk that artificial recharge ofthe palaeochannel wouldmigrate or impact uponaquifers with existingbeneficial uses.Main Issues of concern areincreased groundwaterlevels that may restrictgroundwater discharge fromthe Inner Farm Basinthrough Blatherskite Gap,increased migration ofgroundwater from thepalaeochannel area to theTodd River Channel throughthe AZRI site and adjacentresidential properties andpossible interconnection withthe Tertiary sedimentsthrough old or poorlyconstructed wells.
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Appendix 6: NT Fauna and Flora Database Records
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The following species list is based on records in the NT Fauna Database, supplemented with records from fauna surveys in the region and discussions with the Threatened Species Unit of Parks and Wildlife in Alice Springs. Not all species listed are expected to be found at AZRI. Nomenclature follows that used in the Territory Parks and Wildlife Conservation Act Classification of Wildlife Instrument.
Scientific Name Common Name Conservation Status** Birds Acanthagenys rufogularis Spiny-cheeked Honeyeater Acanthiza apicalis Inland Thornbill Acanthiza chrysorrhoa Yellow-rumped Thornbill Acanthiza uropygialis Chestnut-rumped Thornbill Accipiter cirrhocephalus Collared Sparrowhawk Anthus novaeseelandiae Richards Pipit Ardeotis australis Australian Bustard Vulnerable Artamus cinereus Black-faced Woodswallow Artamus personatus Masked Woodswallow Barnardius zonarius Australian Ringneck Cacatua leadbeateri Major Mitchell's Cockatoo Cacatua roseicapilla Galah Calyptorhynchus banksii Red-tailed Black-cockatoo Near Threatened Chlamydera guttata Western Bowerbird Cheramoeca leucosternus White-backed Swallow Chrysococcyx basalis Horsfield's Bronze-Cuckoo Cincloramphus mathewsi Rufous Songlark Cincloramphus cruralis Brown Songlark Colluricincla harmonica Grey Shrike-thrush Columba livia Rock Dove Conopophila whitei Grey Honeyeater Coracina novaehollandiae Black-faced Cuckoo-shrike Corvus bennetti Little Crow Corvus orru Torresian Crow Coturnix ypsilophora Brown Quail Cracticus nigrogularis Pied Butcherbird Cuculus pallidus Pallid Cuckoo Dicaeum hirundinaceum Mistletoebird Epthianura tricolor Crimson Chat Eurostopodus argus Spotted Nightjar Falco berigora Brown Falcon Falco cenchroides Nankeen Kestrel Falco hypoleucos Grey Falcon
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Scientific Name Common Name Conservation Status** Gallirallus philippensis Buff-banded Rail Birds Geopelia cuneata Diamond Dove Geopelia striata Peaceful Dove Gerygone fusca Western Gerygone Grallina cyanoleuca Magpie-lark Gymnorhina tibicen Australian Magpie Haliastur sphenurus Whistling Kite Hamirostra melanosternon Black-breasted Buzzard Hirundo ariel Fairy Martin Hirundo nigricans Tree Martin Lalage sueurii White-winged Triller Lichenostomus penicillatus White-plumed Honeyeater Lichenostomus virescens Singing Honeyeater Lichmera indistincta Brown Honeyeater Malurus lamberti Variegated Fairywren Malurus leucopterus White-winged Fairywren Malurus splendens Splendid Fairy-wren Manorina flavigula Yellow-throated Miner Melanodryas cucullata Hooded Robin Least Concern Melopsittacus undulatus Budgerigar Merops ornatus Rainbow Bee-eater Microeca fascinans Jacky Winter Milvus migrans Black Kite Mirafra javanica Singing Bushlark Ninox novaeseelandiae Boobook Owl Nymphicus hollandicus Cockatiel Ocyphaps lophotes Crested Pigeon Oreoica gutturalis Crested Bellbird Pachycephala rufiventris Rufous Whistler Pardalotus rubricatus Red-browed Pardalote Petroica goodenovii Red-capped Robin Poliocephalus poliocephalus Hoary-headed Grebe Pomatostomus temporalis Grey-crowned Babbler Psephotus varius Mulga Parrot Rhipidura leucophrys Willie Wagtail Smicrornis brevirostris Weebill Taeniopygia guttata Zebra Finch
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Scientific Name Common Name Conservation Status** Todiramphus pyrrhopygia Red-backed Kingfisher Mammals Antechinomys laniger Kultarr Near Threatened Camelus dromedarius Camel Introduced Canis lupus dingo Dingo Chalinolobus gouldii Gould’s Wattled Bat Chalinolobus morio Chocolate Wattled Bat Felis catus Feral Cat Introduced Onychogalea lunata Crescent Nailtail Wallaby Extinct Macropus rufus Red Kangaroo Mormopterus planiceps Southern Freetail-bat Mormopterus sp.3 Inland Freetail Bat Mormopterus sp. 6. Hairy-nosed Freetail Bat Mus musculus House Mouse Introduced Nyctophilus geoffroyi Lesser Long-eared Bat Oryctolagus cuniculus European Rabbit Introduced Pseudomys desertor Desert Mouse Pseudomys hermannsburgensis Sandy Inland Mouse Scotorepens balstoni Inland Broad-nosed Bat Vespadelus vulturnus Little Forest Eptesicus Reptiles Antaresia stimsoni Stimson's Python Brachyurophis roperi Northern Shovel-nosed Snake Ctenophorus nuchalis Central Netted Dragon Ctenotus helenae Helen's Ctenotus Ctenotus leonhardii Leonhardi's Ctenotus Ctenotus schomburgkii Schomburgk’s Ctenotus Delma nasuta Sharp-snouted Delma Delma tincta Black-necked Snake-lizard Demansia psammophis Yellow-faced Whip Snake Diplodactylus ciliaris Spiny-tailed Gecko Diplodactylus conspicillatus Fat-tailed Gecko Diplodactylus stenodactylus Crowned Gecko Egernia slateri slateri Slater's Egernia Endangered Eremiascincus fasciolatus Narrow-Banded Sand Swimmer Gehyra nana Northern Spotted Rock Dtella Gehyra purpurascens Puple Dtella Gehyra variegata Tree Dtella
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Scientific Name Common Name Conservation Status** Heteronotia binoei Binoes Gecko Lerista bipes Two-toed Lerista Lerista desertorum Desert Lerista Lerista frosti Frost’s Lerista Lerista labialis Sand Lerista Lerista muelleri Mueller’s Lerista Lophognathus longirostris Long-nosed Dragon Menetia greyii Grey’s Menetia Nephrurus levis Three-lined Knob-tailed Gecko Pogona vitticeps Central Bearded Dragon Pseudechis australis King Brown Snake Data Deficient Pseudonaja nuchalis Western Brown Snake Data Deficient Ramphotyphlops endoterus Blind Snake Rhynchoedura ornata Beaked Gecko Simoselaps incinctus Small Snake Tiliqua multifasciata Centralian Blue-tongue Varanus gilleni Pygmy Mulga Monitor Least Concern Varanus gouldii Sand Goanna Vermicella vermiformis Bandy-bandy Amphibians Cyclorana maini Main’s Frog Limnodynastes spenceri Spencer’s Frog Neobatrachus centralis Trilling Frog
**Classification of Wildlife (2003) under Territory Parks and Wildlife Conservation Act 2001 The Northern Territory uses IUCN categories to determine the conservation status of wildlife in the Northern Territory. Under the Act, species that have been classified as Extinct in the Wild, Critically Endangered, Endangered or Vulnerable are considered to be Threatened Wildlife. The criteria used by IUCN to classify the conservation status of species are related to: • The absolute size, number of subpopulations and extent of reduction in population size; • The extent, degree of fragmentation, and degree of fluctuation in geographic range (both
the extent of occurrence and the area of occupancy); and • Quantitative analysis of the probability of extinction. Extinct Taxa not definitely located in the wild during the past 50 years Extinct in the Wild Taxa known to survive only in captivity Critically Endangered Taxa facing an extremely high risk of extinction in the wild in the
immediate future Endangered Taxa facing a very high risk of extinction in the wild in the near
f t
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future Vulnerable Taxa facing a high risk of extinction in the wild in the medium-
term future Near Threatened Taxa that risk becoming Vulnerable in the wild Conservation Dependent Taxa whose survival depends upon ongoing conservation
measures. Without these measures, a conservation dependent taxon would be classed as Vulnerable or more severely threatened
Data Deficient (Insufficiently Known)
Taxa suspected of being Rare, Vulnerable or Endangered, but whose true status cannot be determined without more information
Least Concern Taxa that are not Threatened
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The following species list is based on records in the NT Flora Database, supplemented with records from flora surveys in the region. Not all plants listed are expected to be found at AZRI. Nomenclature follows that used in the Territory Parks and Wildlife Conservation Act Classification of Wildlife Instrument.
Family Scientific Name Conservation StatusACANTHACEAE Rostellularia adscendens
Cheilanthes lasiophylla ADIANTACEAE Cheilanthes sieberi Trianthema portulacastrum Introduced Trianthema triquetra Xerochrysum bracteatum
AIZOACEAE
Zaleya galericulata ssp. galericulata Aerva javanica Alternanthera angustifolia Amaranthus A96904 Alice Springs Amaranthus interruptus Amaranthus viridis Introduced Gomphrena celosioides Ptilotus gaudichaudii Ptilotus macrocephalus Ptilotus nobilis Ptilotus obovatus var. obovatus Ptilotus polystachyus
AMARANTHACEAE
Ptilotus sessilifolius Calotropis procera ASCLEPIADACEAE Marsdenia australis Actinobole uliginosum Brachycome ciliaris complex Calocephalus knappii Calocephalus platycephalus Calotis hispidula Calotis latiuscula Carthamus lanatus Introduced Chrysocephalum apiculatum Conyza bonariensis Introduced Flaveria australasica Gnephosis arachnoidea
ASTERACEAE
Hedypnois cretica Introduced
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Family Scientific Name Conservation StatusIxiochlamys filicifolia Ixiochlamys nana Lactuca serriola Osteospermum muricatum Introduced Polycalymma stuartii Pterocaulon sphacelatum Rhodanthe charsleyae Rhodanthe floribunda Rhodanthe stricta Rhodanthe tietkensii Rutidosis helichrysoides Senecio cunninghamii Senecio gregorii Senecio lautus Senecio magnificus Sonchus oleraceus Vittadinia dissecta var. hirta
ASTERACEAE
Xanthium spinosum Buglossoides arvense Introduced Heliotropium cunninghamii
BORAGINACEAE
Trichodesma zeylanicum Brassica tournefortii Introduced Lepidium africanum Introduced Lepidium muelleriferdinandi Lepidium phlebopetalum Sisymbrium erysimoides Sisymbrium irio Introduced
BRASSICACEAE
Stenopetalum nutans CACTACEAE Opuntia sp. CAESALPINIACEAE Senna artemisioides ssp. filifolia
Wahlenbergia communis CAMPANULACEAE Wahlenbergia tumidifructa Capparis mitchellii Capparis spinosa
CAPPARACEAE
Cleome viscosa CARYOPHYLLACEAE Silene nocturna Introduced
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Family Scientific Name Conservation StatusAtriplex elachophylla Atriplex humifusa Chenopodium auricomum Chenopodium cristatum Chenopodium melanocarpum Chenopodium murale Introduced Chenopodium truncatum Dissocarpus paradoxus Einadia nutans Enchylaena tomentosa Maireana lobiflora Maireana scleroptera Rhagodia eremaea Rhagodia spinescens Salsola tragus Sclerolaena convexula Sclerolaena costata
CHENOPODIACEAE
Sclerolaena lanicuspis Convolvulus clementii Evolvulus alsinoides
CONVOLVULACEAE
Ipomoea polymorpha Citrullus colocynthis Citrullus lanatus
CUCURBITACEAE
Mukia maderaspatana Cyperus involucratus Eleocharis pallens
CYPERACEAE
Fimbristylis dichotoma Euphorbia drummondii Euphorbia hirta Euphorbia hyssopifolia Introduced Euphorbia tannensis
EUPHORBIACEAE
Sauropus trachyspermus Crotalaria smithiana Cullen cinereum Erythrina vespertilio Glycine canescens
FABACEAE
Indigofera colutea
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Family Scientific Name Conservation StatusIndigofera linifolia Indigofera linnaei Lotus cruentus Medicago polymorpha Medicago scutellata Introduced Medicago tornata Introduced Swainsona oroboides Swainsona phacoides
FABACEAE
Tephrosia sphaerospora GERANIACEAE Erodium crinitum
Goodenia heterochila Goodenia lunata
GOODENIACEAE
Lechenaultia divaricata HALORAGACEAE Haloragis aspera JUNCACEAE Juncus bufonius Introduced LAMIACEAE Teucrium racemosum Introduced
Amyema hilliana Amyema maidenii Amyema preissii Lysiana exocarpi ssp. exocarpi
LORANTHACEAE
Lysiana subfalcata Abutilon otocarpum Gossypium bickii Malva parviflora Malvastrum americanum Sida acuta Introduced Sida ammophila Sida cunninghamii
MALVACEAE
Sida fibulifera Marsilea drummondii MARSILEACEAE Marsilea hirsuta
MELIACEAE Melia azedarach Acacia aneura Acacia estrophiolata Acacia farnesiana Acacia murrayana
MIMOSACEAE
Acacia tetragonophylla
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Family Scientific Name Conservation StatusMIMOSACEAE Acacia victoriae MOLLUGINACEAE Mollugo cerviana
Eremophila longifolia Eremophila macdonnellii Eremophila maculata ssp. maculata
MYOPORACEAE
Eremophila sturtii Corymbia eremaea Corymbia opaca Eucalyptus camaldulensis var. obtusa
MYRTACEAE
Eucalyptus coolabah Boerhavia coccinea NYCTAGINACEAE Boerhavia repleta
OLEACEAE Jasminum didymum Oxalis corniculata Introduced OXALIDACEAE Oxalis perennans Argemone ochroleuca ssp. ochroleuca
Introduced
Papaver hybridum Introduced
PAPAVERACEAE
Papaver somniferum Introduced PITTOSPORACEAE Pittosporum angustifolium POACEAE Aristida biglandulosa
Aristida contorta Aristida holathera Bothriochloa ewartiana Bromus catharticus Introduced Bromus diandrus Introduced Cenchrus ciliaris Introduced Cenchrus longispinus Introduced Chloris inflata Chloris pectinata Chloris virgata Chrysopogon fallax Cynodon dactylon Dactyloctenium radulans Dichanthium annulatum Introduced Dichanthium sericeum Digitaria brownii
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Family Scientific Name Conservation StatusDigitaria coenicola Echinochloa colona Introduced Echinochloa esculenta Introduced Enneapogon avenaceus Enneapogon polyphyllus Enteropogon acicularis Enteropogon ramosus Eragrostis barrelieri Eragrostis cilianensis Eragrostis dielsii Eragrostis eriopoda Eragrostis kennedyae Eragrostis leptocarpa Eriachne helmsii Eriachne mucronata Eulalia aurea Hordeum glaucum Introduced Lolium rigidum Introduced Melinis repens Panicum antidotale Introduced Panicum decompositum Panicum miliaceum Paspalidium constrictum Setaria verticillata Introduced Sporobolus pyramidalis Introduced Themeda triandra Tragus australianus Tripogon loliiformis Triraphis mollis
POACEAE
Urochloa piligera Acetosa vesicaria Emex australis Introduced Muehlenbeckia florulenta
POLYGONACEAE
Polygonum aviculare Introduced PORTULACACEAE Portulaca oleracea
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Family Scientific Name Conservation
Status Grevillea striata Hakea divaricata Hakea eyreana
PROTEACEAE
Hakea leucoptera PROTEACEAE Hakea lorea RHAMNACEAE Ventilago viminalis SANTALACEAE Santalum lanceolatum
Atalaya hemiglauca SAPINDACEAE Dodonaea viscosa ssp. angustissima
SCROPHULARIACEAE Stemodia florulenta Nicotiana megalosiphon Solanum chenopodinum Solanum ellipticum
SOLANACEAE
Solanum quadriloculatum Tribulus eichlerianus ZYGOPHYLLACEAE Tribulus terrestris
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Appendix 7: Construction Environmental Management Plan Soil Aquifer Treatment Scheme
Soil Aquifer Treatment Construction Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005 Prepared for: Power and Water Corporation PO Box 1521 ALICE SPRINGS NT 0871
Report by: HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia Ph: +61 8 8935 0515 Fax: +61 8 8932 5369 HLA Ref: B600270_RPT_Final_SATCEMP_11Apr05.doc
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DISTRIBUTION Soil Aquifer Treatment Construction Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005
Copies Recipient Copies Recipient 1 Mark Skinner
Senior Project Manager PO Box 1521 ALICE SPRINGS NT 0871
This document was prepared for the sole use of Power and Water Corporation and the regulatory agencies that are directly involved in this project, the only intended beneficiaries of our work. No other party should rely on the information contained herein without the prior written consent of HLA-Envirosciences Pty Limited and Power and Water Corporation.
By HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia
____________________________________ Alana Eggleton Environmental Scientist
Peer Review: Date:
11 April 2004
Dr Sandy Griffin Principal Environmental Scientist
Soil Aquifer Treatment Construction Environmental Management Plan, Alice Springs Water Reuse Scheme
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CONTENTS
1 THE SAT CONSTRUCTION EMP................................................................................. 1 1.1 Introduction ..................................................................................................... 1 1.2 Background..................................................................................................... 1 1.3 Purpose........................................................................................................... 2 1.4 Risk Assessment ............................................................................................ 2 1.5 Management Strategies.................................................................................. 3
2 SOIL AND EROSION MANAGEMENT SUB-PLAN ..................................................... 4 2.1 Issues and Impacts......................................................................................... 4 2.2 Objectives ....................................................................................................... 4 2.3 Applicable Legislation, Policies and References ............................................ 4 2.4 Risk Assessment ............................................................................................ 5 2.5 Management Action – Soil and Erosion ......................................................... 6
3 WATER MANAGEMENT SUB-PLAN ........................................................................... 9 3.1 Issues and Impacts......................................................................................... 9 3.2 Objectives ....................................................................................................... 9 3.3 Applicable Legislation, Policies and References ............................................ 9 3.4 Risk Assessment .......................................................................................... 10 3.5 Management Actions – Water ...................................................................... 11
4 WASTE MANAGEMENT SUB-PLAN ......................................................................... 13 4.1 Issues and Impacts....................................................................................... 13 4.2 Objectives ..................................................................................................... 13 4.3 Applicable Legislation, Policies and References .......................................... 13 4.4 Risk Assessment .......................................................................................... 14 4.5 Management Actions – Wastes .................................................................... 15
5 HAZARDOUS SUBSTANCES MANAGEMENT SUB-PLAN ..................................... 16 5.1 Issues and Impacts....................................................................................... 16 5.2 Objectives ..................................................................................................... 16 5.3 Applicable Legislation, Policies and References .......................................... 16 5.4 Risk Assessment .......................................................................................... 17 5.5 Management Actions – Hazardous Substances........................................... 18
6 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN ...................... 19 6.1 Issues and Impacts....................................................................................... 19 6.2 Objectives ..................................................................................................... 19 6.3 Applicable Legislation, Policies and References .......................................... 19 6.4 Risk Assessment .......................................................................................... 20 6.5 Management Actions - Vegetation, Fauna and Habitat................................ 21
7 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN ..................................... 23
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7.1 Issues and Impacts....................................................................................... 23 7.2 Objectives ..................................................................................................... 23 7.3 Applicable Legislation, Policies and References .......................................... 23 7.4 Risk Assessment .......................................................................................... 24 7.5 Management Actions – Weeds and Pest Species........................................ 25
8 FIRE MANAGEMENT SUB-PLAN .............................................................................. 27 8.1 Issues and Impacts....................................................................................... 27 8.2 Objectives ..................................................................................................... 27 8.3 Applicable Legislation, Policies and References .......................................... 27 8.4 Risk Assessment .......................................................................................... 28 8.5 Management Actions – Fire.......................................................................... 29
9 HERITAGE MANAGEMENT SUB-PLAN.................................................................... 30 9.1 Issues and Impacts....................................................................................... 30 9.2 Objectives ..................................................................................................... 30 9.3 Applicable Legislation, Policies and References .......................................... 30 9.4 Risk Assessment .......................................................................................... 31 9.5 Management Actions – Heritage .................................................................. 32
10 AIR QUALITY MANAGEMENT SUB-PLAN ............................................................... 33 10.1 Issues and Impacts....................................................................................... 33 10.2 Objectives ..................................................................................................... 33 10.3 Applicable Legislation, Policies and References .......................................... 33 10.4 Risk Assessment .......................................................................................... 34 10.5 Management Actions – Air Quality ............................................................... 35
11 NOISE MANAGEMENT SUB-PLAN ........................................................................... 37 11.1 Issues and Impacts....................................................................................... 37 11.2 Objectives ..................................................................................................... 37 11.3 Applicable Legislation, Policies and References .......................................... 37 11.4 Risk Assessment .......................................................................................... 38 11.5 Management Actions – Noise....................................................................... 39
12 ACCESS AND PUBLIC SAFETY................................................................................ 40 12.1 Issues and Impacts....................................................................................... 40 12.2 Objectives ..................................................................................................... 40 12.3 Applicable Legislation, Policies and References .......................................... 40 12.4 Risk Assessment .......................................................................................... 40 12.5 Management Actions – Access and Public Safety ....................................... 41
13 INDUCTION TRAINING REQUIREMENTS................................................................. 42 14 MONITORING FRAMEWORK..................................................................................... 43
14.1 Environmental Condition............................................................................... 43 14.1.1 Groundwater Monitoring................................................................ 43 14.1.2 Monitoring Soil Erosion ................................................................. 45 14.1.3 Dust, Noise and Odour Complaints Monitoring............................. 45
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14.1.4 Vegetation, Habitat and Fauna monitoring.................................... 47 14.1.5 Mosquito / Biting Insect Monitoring ............................................... 47
14.2 Environmental Management......................................................................... 47 15 AUDITING.................................................................................................................... 48
15.1 Periodic Review ............................................................................................ 48 15.2 Environmental Audit...................................................................................... 48 15.3 Non-conformance Procedures...................................................................... 49
TABLES
Table 1: Measure of Likelihood ....................................................................................................2 Table 2: Measure of Consequence ..............................................................................................3 Table 3: Risk Assessment Scoring...............................................................................................3 Table 4: Risk Assessment for Soil and Erosion Issues................................................................5 Table 5: Risk Assessment for Water Issues...............................................................................10 Table 6: Risk Assessment for Waste Management Issues........................................................14 Table 7: Risk Assessment for Hazardous Substances Issues...................................................17 Table 8: Risk Assessment for Vegetation, Fauna and Habitat Issues .......................................20 Table 9: Risk Assessment for Weeds and Pest Species ...........................................................24 Table 10: Risk Assessment for Fire Issues ................................................................................28 Table 11: Risk Assessment for Heritage Issues.........................................................................31 Table 12: Risk Assessment for Air Quality Issues......................................................................34 Table 13: Risk Assessment for Noise Issues .............................................................................38 Table 14: Risk Assessment for Access and Public Safety.........................................................40 Table 15: Groundwater Monitoring during Commissioning ........................................................44
Soil Aquifer Treatment Construction Environmental Management Plan, Alice Springs Water Reuse Scheme
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1 THE SAT CONSTRUCTION EMP 1.1 Introduction This Construction Environmental Management Plan (CEMP) has been prepared for construction of the Soil Aquifer Treatment (SAT) basins and associated infrastructure at the Arid Zone Research Institute (AZRI), located approximately 10 km south of Alice Springs, Northern Territory. The Public Environment Report (PER) Guidelines issued by the Office of Environment and Heritage (OEH) required the submission of EMPs to accompany the PER. This CEMP has been developed in accordance with the guidelines for the Alice Springs Water Reuse Scheme PER. A detailed description of the proposed Alice Springs Water Reuse Scheme is provided in the Public Environment Report, which accompanies this CEMP. This CEMP outlines the measures to manage the environmental integrity of the site during construction activities. The principal objective of the CEMP is to provide effective and practical management strategies that will avoid, ameliorate or mitigate potential adverse impacts associated with the construction of the SAT and its associated infrastructure. The CEMP includes clear instructions for management, monitoring and performance evaluation and is guided by the relevant legislation and other codes of practice.
1.2 Background The Alice Springs Water Reuse Scheme proposes to utilise SAT technology to polish and store in groundwater aquifers recycled water from the Alice Springs Waste Stabilisation Ponds, for later extraction and use for horticultural irrigation. Recycled water will be transferred from the WSP to infiltration basins for ’filtration‘ by the natural biological and geochemical processes of the soils. The recycled water will permeate through the soil from the infiltration basins to the temporary aquifer below where physical, chemical and/or microbial process will continue to reduce the concentration of pollutants. The scheme is expected to produce up to 6 ML of recycled water per day for reuse. The water quality will be suitable for reuse in accordance with national water quality guidelines and will be subject to regulation under the Water Act and Public Health Act.
Construction of the SAT basins and the associated infrastructure will involve the following stages: • Site marking and site works; • Construction of temporary access tracks; • Vegetation clearing; • Excavation of basins; • Establishment of pipeline to basins; • Establishment of groundwater monitoring bores; and • Landscaping and revegetation of disturbed areas surrounding basins.
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1.3 Purpose The CEMP aims to: • Provide details of proposed measures to prevent or minimise adverse impacts and assess
the likely effectiveness of these safeguards; • Ensure that safeguards are being effectively applied; • Enable remedial action for any impacts that were not anticipated in the PER; • Determine the differences between predicted and actual impacts (via monitoring); and • Provide for the periodic review of the management plan itself. The CEMP provides an ongoing interactive process for defining, documenting and improving the environmental management of the SAT construction. The CEMP is intended to be a ‘living’ document which allows for it to be continuously updated reflecting feedback from the reporting conducted under the plan and recommendations arising from monitoring and audits. This CEMP is accompanied by an Operation EMP (OEMP) for the operation of the SAT facilities. The OEMP addresses the management of environmental impacts associated with operational activities.
1.4 Risk Assessment A risk assessment, based on AS4360:1999 Risk Management, was undertaken on the potential environmental incidences that may arise during the construction activities for the SAT scheme. The risk assessment combines (qualitative) estimates of the likelihood of a certain event or environmental impact occurring (Table 1) and the consequence (Table 2). Table 1: Measure of Likelihood Level Descriptor Description
1 Rare Environmental impact may occur only in exceptional circumstances 2 Unlikely Environmental impact could occur at some time based on current
practices 3 Moderate Environmental impact has a moderate probability of occurring based
on current practices 4 Likely Environmental impact will probably occur based on current practices 5 Almost Certain Environmental impact is expected to occur in most circumstances or
is already occurring
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Table 2: Measure of Consequence Level Descriptor Description
1 Insignificant Negligible short term environmental impact to habitat with no monitoring required
2 Minor Some short term environmental disturbance with localised impacts, some management required
3 Moderate Obvious environmental impact to habitat, more widespread effects, normal incident management response is sufficient
4 Major Substantial environmental harm, loss of immediate habitat, widespread side effects over extended time, long term remediation management required, external agencies utilised
5 Catastrophic High degree of environmental harm, permanent loss of widespread habitat, loss of species, external agencies utilised, incident of regional significance
The likelihood of an event occurring is multiplied by the environmental consequence in order to determine the significance of the impact and, hence, its priority for management (Table 3). Table 3: Risk Assessment Scoring
Score Management required 25 Extreme risk: immediate action required to intervene and prevent incident.
15 – 20 High risk: prompt senior management attention of potential environmental impact. 10 – 14 Moderate risk: high priority issue requiring regular management and monitoring. 6 – 9 Low risk: low priority issue that can be managed by routine procedures 1 – 5 Insignificant risk: issue of low importance not requiring management but only
occasional monitoring.
The results of the risk assessment have been provided in each aspects sub-plan.
1.5 Management Strategies The following sections provide a description of each aspect or activity that has the potential to impact on the environment and strategies for the management of these potential impacts. Reference has been made to the appropriate section of the PER, where appropriate.
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2 SOIL AND EROSION MANAGEMENT SUB-PLAN 2.1 Issues and Impacts Soil management during construction of the SAT system will primarily involve management of soil erosion issues. All construction activity involving vegetation clearing and soil excavation has the potential to impact on surface water systems through soil erosion processes. The primary soil erosion issues associated construction activities are: • Soil erosion – potential for disturbed soils and fill to be transported by surface flow during
rainfall events and/or onsite water usage or during periods of strong winds; • Dust generation - potential for vehicle movement or strong winds to cause loose soil (dust)
to be transported off-site; • Pollution of soils through spillage of oils, lubricants, fuels and other hazardous compounds
used by construction vehicles and machinery; • Compaction - heavy vehicles moving on site during excavation may cause soil compaction.
Compaction of soil may impact on soil permeability and therefore effectiveness of the SAT basins; and
• Top soil – topsoil removed during site works, which could possibly be used in a later phase of construction, may need to be stockpiled on the SAT site. During a rainfall event, topsoil may be washed into local drainage channels causing sedimentation or it may be a source of dust during periods of strong winds.
2.2 Objectives • To prevent degradation of soil at the site; • To minimise soil erosion on the development site; • To minimise dust impacts on sensitive receiving areas (residential, vegetated areas) during
construction; and • To implement measures for stabilisation of disturbed areas.
2.3 Applicable Legislation, Policies and References The following legislation applies to soil and erosion management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Soil Conservation and Land Utilization Act 1980;• Water Act 1992; and • Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures includes: • National Environmental Protection (Assessment of Site Contamination) Measure 1999. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 59 to 77; and
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• SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Vegetation, Fauna and Habitat Management Sub-plan, the Air Quality Sub-plan and the Access and Public Safety Sub-plan are related to this Sub-plan.
2.4 Risk Assessment Table 4: Risk Assessment for Soil and Erosion Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Accelerated erosion from vehicle movement on site during construction activities
4 3 12 MErosion of soil
Sedimentation of St Mary’s Creek should rainfall events occur during the construction phase, causing loose soil to be washed into the creek channel
2 4 8 L
Generation of dust by vehicle movement and general construction operations (i.e. clearing, site works, excavation for SAT basins)
3 3 9 LCreation of Dust
Dust settling on local drainage channels water, increasing turbidity and reducing transfer of oxygen from air to water
2 2 4 I
Pollution of Soils Spillage or leaks of oils, lubricants, fuels or other hazardous substances used by construction machinery
3 3 9 L
Compaction Changes to soil structure and permeability as a result of compaction from construction vehicles
4 2 8 L
Introduction of Soil Pathogens and Weeds
Potential for introduction of pathogens and weeds through the importation of fill for construction activities
3 3 9 L
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2.5 Management Action – Soil and ErosionEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Ensure roads and tracks, as well as all builtinfrastructure, incorporate drainage controls tocontain and control water runoff during rainfallevents
Contractor Regular audit/ inspection ofthe site to ensure measuresare being implemented andare effective
During rainfall events, monitor the surface waterrunoff to determine whether erosion controlmeasures are effective. If it is found that significantlevels of sediments are moving off-site, sedimentcontrol measures, i.e. silt fencing and temporarysediment retention basins, should be installed
Power & WaterContractor
Inspection of runoff from SATsite for any significantmovement of sediments nearfence line or drainage lines
Water erosionprevention strategy
Avoid placing stockpiles near boundary of SAT siteto limit the impact of runoff from site
Contractor Provide designated area forsoil stockpiling wheremeasures can be taken tominimise impact onsurrounding environment
No increase in movement ofsurface sediment off-site
If strong winds are blowing towards residentialareas all dust producing activities shall beminimised
ContractorPower & Water
Daily assessment of weatherconditions (particularly windspeed), dust generation andactivities causing dustgeneration
If excessive dust is noted, exposed road surfacesshall be wet down using water cart or sprinklersystems as required
Contractor Instigate a dust monitoringprogrammeDevelop a complaints registerto record any dust complaints
Wind erosion preventionstrategy
Vehicles must travel at <20 km/hr over unsealedroads to keep dust levels down
ContractorPower & Water
Speed limit signageTraining of site personnel
Dust results are withinrelevant environmental dustcriteria (NEPM)No dust complaints
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaMinimise vehicle access across site to thatnecessary
ContractorPower & Water
Training of site personnelAppropriate signage
Restrict movement on boundary firebreaks to thatrequired for AZRI property management
ContractorPower & Water
Regular road and trackmaintenance
Design and construct roads to reduce dustgeneration
Contractor
Access tracks to be maintained to minimise fine,loose particulates
Power & Water Designated equipment andpersonnel for trackmaintenance
Minimise exposed soil surfaces within the SAT site Power & WaterRevegetate disturbed areas not required to becleared for SAT area (e.g. temporary fill storagesite)
Power & Water Implementation ofrevegetation strategy
Wind erosion preventionstrategycontinued
No soil stockpiles are to be left exposed on site ContractorPower & Water
Appropriate controls forminimising dust generation(i.e. cover with tarp or grassand locate downwind ofsensitive receiving areas(residential)
Dust results are withinrelevant environmental dustcriteria (NEPM)No dust complaints
Soil contaminationmitigation
Develop and implement appropriate waste disposaland fuel storage areas to current Australianstandards to minimise risk of spills and leaks
ContractorPower & Water
Bunded areas/containment orcontrol structuresRegular audits to ensurecompliance with EMP
No staining on surface soilaround fuel and otherchemical storage areas
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaProvide procedures to manage fuel and otherchemical spills including use of fuel spill kits
Soil contaminationmitigationcontinued Provide appropriate containment and control
ContractorPower & Water
Training of site personnel torespond to incidencesDispose of hazardouschemicals and liquid wastes toan authorised landfillMaintain register of hazardoussubstances and fuels comingonto siteRegular audits to ensurecompliance with EMP
No staining on surface soilaround fuel and otherchemical storage areas
Limit the number of vehicles and earthmovingequipment travelling across site to what isnecessaryPrevent movement on or working of soils while wet
Training of site personnelRegular audit/ inspection ofthe site
Fit earthmoving equipment with low flotation tyres Appropriate tyres for vehicles
Compaction
Remediate any areas which have been compactedby rip/furrow/aeration of the soils
ContractorPower & Water
Landfarming/landscapingequipment
No significant compaction ofsoils is occurring
If stockpile of soil or other materials occur on site,must be in conjunction with the site requirementsEnsure stockpile is stable by undertakingappropriate controls measures, i.e. cover with tarpor other stabilising agent
Stockpile management
Ensure stockpiles are >50 m from local residencesor drainage corridors
ContractorPower & Water
Provide a designated area forstockpiling
Dust results are withinrelevant environmental dustcriteria (NEPM)No dust complaints
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3 WATER MANAGEMENT SUB-PLAN 3.1 Issues and Impacts There are four main sources of water that exist or may be generated on site during construction of the SAT system. These include: • Groundwater - the construction works for the SAT facilities has the potential to impact on
the groundwater height and chemistry. The contamination of groundwater may occur as the result of accidental spills and or leakage of toxic or hazardous substances. Compaction and excavation activities which are likely to occur during construction may cause the diversion of groundwater flow;
• Surface Water - generated through rainfall events or from using water during construction activities can result in contaminated surface waters running off into existing drainage areas. This has the potential to pollute surface water, through the movement of silt and other particulates and may also interfere with existing surface water flow patterns;
• Stormwater– stormwater runoff from the SAT construction site generated during periods of heavy rainfall or the general use of water on site may result in contamination of stormwater drains; and
• Wastewater – generated from wash down activities during construction. This may result in contamination of soil, groundwater, stormwater and surface water on site and off-site.
3.2 Objectives • To manage construction activities to prevent impact on groundwater systems aquifers by
contaminants or soil erosion; • To minimise potential impacts upon surface water, as a result of construction activities; and • To comply with legislative requirements.
3.3 Applicable Legislation, Policies and References The following legislation applies to water management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Water Act 1992; and • Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures include: • The Northern Territory Procurement Code (National Code of Practice for the Construction
Industry adapted for specific application in the Northern Territory); • National Environmental Protection (Assessment of Site Contamination) Measure 1999; and • Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 78 to 119; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme.
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The Soils Management Sub-plan, Waste Management Sub-plan and Hazardous Products Management Sub-plan are related to this Sub-plan.
3.4 Risk Assessment Table 5: Risk Assessment for Water Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Contamination of groundwater from construction activity
2 2 4 I
Over-pumping of bore water 2 2 4 I
Contamination and Alteration of Groundwater
Contamination of groundwater by drilling and installation of monitoring and test production wells
2 3 6 L
Surface water contamination due to soil erosion runoff
4 2 8 LContamination of Surface water
Contamination of surface water through fuel or chemical spills
3 2 6 L
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3.5 Management Actions – WaterEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Establish a groundwater monitoring programmeusing existing and new groundwater extractionbores. While construction activities are unlikely tohave a significant impact on groundwater,establishing monitoring prior to the operationalphase, will allow for baseline data collection
Power & Water Installation of groundwatermonitoring bores, drainagebores and barriersRoutine monitoring of waterfrom extraction boresResources to record andmanage analytical results
No adverse impact ongroundwater qualityNo significant change ingroundwater height
Site personnel vehicle and earthmoving equipmentshould park and move only on existing or newservice roads to minimise the compaction of soilsand the interruption of groundwater flows
No parking in vegetated areas
All construction equipment washdown will beconducted off-site
Induction for all constructionemployees
No washdown on site
Groundwatercontamination mitigation
Contain all accidental release or spills ofhydrocarbons and chemicals used duringconstruction activities
ContractorPower & Water
Provide spill kits No staining on surface soilaround fuel and otherchemical storage areas
Construction activities should be carried out duringthe dry season to reduce the risk for surfacewater/stormwater runoff
ContractorPower & Water
No major construction workduring peak rainfall period
During rainfall events, undertake regularinspections of drains and nearby sensitive receivingwaters to ensure they are not being undulyimpacted upon from sedimentation
Power & Water Regular inspections ofdrainage areas
No change in existing runoffpattern
Surfacewater/Stormwatercontamination mitigation
If required, establish erosion control measures, i.e.silt traps, retention basins, within identified runoffareas
ContractorPower & Water
Installation of erosion controlmeasures
No erosion occurring on site
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaSurfacewater/Stormwatercontamination mitigationcontinued
Contain all hazardous substances, fuels andchemicals, in appropriate areas (i.e. bunding,containment areas and control structures)
ContractorPower & Water
Maintenance of bunded areas,containment or controlstructuresDispose of waste chemicals toan authorised landfill whererequiredMaintain register of hazardoussubstances and fuels comingonto site
No incidences of fuel leaks orspillsNo staining on surface soilaround fuel and otherchemical storage areas
Any waste produced during construction activities(i.e. cement mixers, fuels and other chemicals)should not be released onto ground or intostormwater drains. Suitable hydrocarbon andchemical containment measures should beundertaken, such as portable bunding.Any waste water produced during constructionworks should be removed off-site to an approvedfacility
Wastewatermanagement practices
All construction equipment wash down is to occuroff-site
ContractorPower & Water
Undertake audits forcomplianceMaintenance of bunded areas,containment or controlstructures for all potentialgenerated wastewater
No adverse impact ongroundwater quality
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4 WASTE MANAGEMENT SUB-PLAN 4.1 Issues and Impacts Waste will be generated in the construction phase of the SAT system. The types of waste may include: • Rubble and excess soil; • Fuels, oils and lubricants; and • Organic waste from clearing operations. The associated impacts from the generation of waste materials are: • Potential to attract fauna, such as birds, to the site because of uncovered organic
materials; • Increased number of disease carrying organisms such as flies and mosquitoes; • Potential to cause odours; • Stockpiling of inorganic material can impact on the visual amenities of the area; and • Rubble and other materials may block stormwater drains and cause sedimentation and
pollution within local drainage channels.
4.2 Objectives • To minimise the quantities of wastes produced during construction activities; • To ensure wastes are properly stored, transported and disposed from site; • To prevent impacts on the surrounding natural environment and on human health (i.e.
prevention of spills); and • To reduce, reuse and recycle wastes where possible.
4.3 Applicable Legislation, Policies and References The following legislation applies to waste management: • Waste Management and Pollution Control Act 1998;• Soil Conservation and Land Utilization Act 1980;• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Public Health Act 1981;• Dangerous Goods Act 1981; and • Environmental Assessment Act 1982.
Relevant policies, codes of practice and measures includes: • National Environmental Protection (Assessment of Site Contamination) Measure 1999. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and
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• SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soil Management Sub-plan, Water Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan, Weed and Pest Species Management Sub-plan and Air Quality Management Sub-plan are related to this Sub-plan.
4.4 Risk Assessment Table 6: Risk Assessment for Waste Management Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Pest attraction to organic wastes 4 2 8 LLoss of visual amenity 4 2 8 L
Generation of solid waste
Odours produced from putrescible waste materials 3 2 6 LGeneration of liquid waste
The generation of minor waste oils from vehicles, operational equipment and pumps
3 2 6 L
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4.5 Management Actions – WastesEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Provide putrescible waste bins for storage ofdomestic waste (i.e. food, paper, wrappers) prior toremoval from siteIf required, dispose putrescible wastes inappropriate storage bins and transport to aappropriately licensed green waste facilityPutrescible waste bins are to be covered at alltimes
Adequate Waste disposalfacilities on site (covered bins)Adequate transport of wastesoff-site to an approvedlicensed landfill facility whererequiredTraining of site personnel
Reuse vegetative matter from clearing operations inthe form of mulch and/or in landscaping orenhancement of buffers
Solid waste -putrescible materialscontrol
Vegetated waste can also be allocated to localcommunities for firewood if appropriate
ContractorPower & Water
Resources forlandscaping/enhancementwork
No odour complaintsNo loss of visual amenityReuse of vegetated materialon site rather than transfer tolandfill
Provide non-putrescible waste bins for storage ofdomestic waste (i.e. food, paper, wrappers) prior toremoval from siteSeparation recyclable wastes (paper andcardboard, other containers)
Provide adequate wastedisposal facilities (coveredbins), including separate binsfor recyclable materials
Solid wastes - non-putrescible materialscontrol
Non-recyclable wastes are to be transported to anapproved disposal facility (concrete, steel cut-offs,electric cables and general refuse)
ContractorPower & Water
Provide adequate transport ofnon-recyclable materials off-site
No litter located on site
Liquid waste control Ensure disposal of waste oils from vehicles,operational equipment and pumps is by a licensedwaste disposal contractor
ContractorPower & Water
Provide adequate transport ofwastes off-site by an approvedwaste disposal contractor
No on site disposal of liquidwastes
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5 HAZARDOUS SUBSTANCES MANAGEMENT SUB-PLAN
5.1 Issues and Impacts The principal issue associated with the use of hazardous substances for the construction of the SAT facilities is: • Inappropriate use, handling and storage of hazardous products or chemicals that can result
in impacts on the surrounding environment, site workers, land users and the surrounding community.
The potential impacts on the environment include: • Contamination of groundwater and soil; • Contamination of surface water; and • Impacts on water quality and biological aspects of the area. The potential impacts on site workers, land users and neighbouring properties include: • Potential injury (long or short term) as a result of incorrect handling and storage
procedures; and • Potential legislative action as a result of incorrect handling and storage procedures.
5.2 Objectives • To prevent contamination of soil or water through spillage of hazardous substance; • To manage hazardous material use and disposal in a manner which minimises the risk to
the surrounding environment and for the safety of the employees and public; and • To comply with legislation and regulatory requirements.
5.3 Applicable Legislation, Policies and References The following legislation applies to hazardous substance management: • Waste Management and Pollution Control Act 1998;• Dangerous Goods Act 1981;• Soil Conservation and Land Utilization Act 1980;• Water Act 1992; and • Work Health Act 1986 and Regulations. Relevant policies, codes of practice and measures include: • National Environmental Protection (Assessment of Site Contamination) Measure 1999; • National Code of Practice for the Control of Workplace Hazardous Substances
(NOHSC:2007, 1994);
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• Australian Standards for storage, handling and assessment of risks associated with hazardous substances;
• Northern Territory Work Health (Occupational Health And Safety) Regulations (as in force at 26 November 2003) Part 7;
• Storage and handling of hazardous substances in accordance with Northern Territory Work Health (Occupational Health and Safety) Regulations (as in force at 26 November 2003) Part 7; and
• Storage and handling of hazardous substances in accordance with National Code of Practice for the Control of Workplace Hazardous Substances (NOHSC:2007, 1994).
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Air Quality Sub-plan and Access and Public Safety Sub-plan are related to this Sub-plan.
5.4 Risk Assessment Table 7: Risk Assessment for Hazardous Substances Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Accidental fuel spills associated with construction and storage activities on site and wash down of vehicles
3 2 6 LHazardous materials management
Hazardous Materials – chemical usage and spills (i.e. chemicals, herbicides and pesticides)
3 2 6 L
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5.5 Management Actions – Hazardous SubstancesEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Hazardous chemicals used on site to be handled andstored in accordance with the National Code ofPractice for the Control of Workplace HazardousSubstances (NOHSC:2007, 1994)
Detailed hazardoussubstances management andstorage proceduresHandling, storage anddisposal of hazardoussubstance training for sitepersonnel
A register (stock inventory) and Material Safety DataSheets (MSDS) must be available for all hazardoussubstances used during construction activities
MSDS records and incidentreporting
Develop an emergency spills procedure including thereporting of all spills and environmental incidents toNT Department of Infrastructure, Planning andEnvironment through the Waste Management &Pollution Control Register or Pollution Response Line1800 064 567
Training of constructionpersonnel in the use andstorage of hazardoussubstance and how to respondto a incident
Hazardous substances and chemicals are to be storedin approved containers, off groundBunding or other containment to be used forhazardous substances where requiredAny on-site machinery refuelling should be carried outin an approved area where any spills and leaks ofhazardous substances can be contained.
Hazardoussubstance/chemicalcontrols
Any spills that occur must be remediated to thesatisfaction of the regulatory authorities
Contractor
Undertake regularaudit/inspections of the site toensure safety measures inhandling and storage ofhazardous substances arebeing implementedProvide bunded areas andother containment facilitiesand maintain
No accidental spills or leakageof hazardous substancesNo evidence of fuel or otherchemical residue from leakageor spills on siteAll personnel aware of spillsprocedures
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6 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN
6.1 Issues and Impacts There is a potential that construction activities for the SAT scheme could impact on the vegetation and habitats surrounding the site and the native fauna in the area. The potential impacts that may occur include:
• Loss or alteration of habitat through clearing of vegetation; • Degradation of the adjacent vegetated areas through changes in hydrology and
compaction; • Disturbance to fauna on site through the creation of artificial fauna attractants, which may
result in harm to fauna, or interfere with construction activities; and • Loss of threatened fauna and flora from the area (either temporarily during site activity or
permanently); this can be the result of inappropriate clearing which can contribute to land degradation and the loss of biodiversity.
6.2 Objectives • To protect Threatened species or any area of environmental or cultural significance; and • To limit the impact upon habitat of native species through management practices.
6.3 Applicable Legislation, Policies and References The following legislation applies to vegetation, fauna and habitat management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Territory Parks and Wildlife Conservation Act 2000;• Weeds Management Act 2001;• Bushfires Act 2004;• Plant Diseases Control Act 2000; and • Soil Conservation and Land Utilization Act 2001.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Waste Management Sub-plan, Weed and Pest Management Sub-plan and Fire Management Sub-plan are related to this Sub-plan.
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6.4 Risk Assessment Table 8: Risk Assessment for Vegetation, Fauna and Habitat Issues
Issue Priority Environmental
Issue Potential Environmental Incidents Likelihood
Consequence
Total
Priority
Loss of vegetation 2 2 4 ILoss of Threatened species of flora or fauna 2 4 8 LDisturbance to fauna 3 3 6 L
Impact to vegetation, fauna and habitat
Loss of habitat 2 2 4 I
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6.5 Management Actions - Vegetation, Fauna and HabitatEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Minimise areas cleared during construction of thesite to that actually required for development of theSAT scheme
ContractorPower & Water
Ensure only nominated areas are targeted duringclearing activities
Contractor
No clearing of areas outside ofdesignated construction site
Retain large/mature trees and shrubs, whereverpractical, especially hollow-bearing River RedGums
ContractorPower & Water
Retention of environmentallyor culturally significant trees inlocations where they will notimpact on SAT operations
Obtain permission to clear from AAPA (AboriginalAreas Protection Authority)
Power & Water
Clearing plan showing areasto be retained, boundaries ofconstruction site and bufferareas
Certificate of Authority issued
Use cleared vegetative matter to enhance buffers ContractorPower & Water
Personnel to undertake bufferenhancement
Confine parked earthmoving vehicles and workersvehicles to set parking areas (on existing serviceroads and tracks) to minimise the impact on nativeflora
Contractor Training of site personnel No parking in vegetated areas
Undertake targeted Threatened flora speciessurvey prior to commencement of clearing
ContractorPower & Water
Qualified botanist to undertakesurvey
Native floramanagement
If Threatened flora species located, develop, inconjunction with the Office of Environment &Heritage, a Threatened species managementprogramme
Power & Water Personnel to developmanagement strategy
No Threatened flora speciesdisturbed without adequateand approved controls in place
Environmental Controls Mitigation and Management Responsibility Resources Performance Criteria
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Maintain a clean and tidy work area to ensure thatnative fauna are not attracted to the constructionsite
ContractorPower & Water
Provide covered bins andminimise water ponding
No incidences of faunaattracted to waste
Use amber lighting as an alternative to white lightsto attract fewer insects which will reduce the chanceof attracting insect-eating fauna to the site (thisshould only occur where use of amber lighting doesnot conflict with OH&S requirements)
Power & Water
Retain large/mature trees and shrubs, whereverpractical, especially hollow-bearing River RedGums
ContractorPower & Water
Clearing plan showing areasto be retained, boundaries ofconstruction site and bufferareas
Retention of environmentallysignificant trees in locationswhere they will not impact onSAT operations
Enhancement of buffers to increase their value aswildlife corridors and habitat areas, using vegetativematerial cleared during construction
ContractorPower & Water
Personnel to undertake bufferenhancement
Undertake targeted Threatened fauna speciessurvey prior to commencement of clearing
ContractorPower & Water
Qualified zoologist toundertake survey
Native faunamanagement
If Threatened fauna species located, develop, inconjunction with the Office of Environment &Heritage, a Threatened species managementprogramme
Power & Water Personnel to developmanagement strategy
No Threatened fauna speciesdisturbed without adequateand approved controls in place
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7 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN
7.1 Issues and Impacts The introduction of weeds and pest species during the construction phase may cause environmental impacts to the project site. Weeds have the potential to: • Increase the risk of wildfire; • Compete with native plants; • Change the micro-habitat; • Encourage an excessive use of herbicide use in weed control; and • Affect visual amenity. The introduction of weeds during the construction phase will possibly be by vehicles entering the site carrying seed and seed in any fill that is imported to the site. Additionally weed seed may be carried on to the site by wind and water movement or by animals. During the construction phase new and existing weed species may become more rapidly established because of the associated disturbed ground related to the construction activities. Pest species have the potential to adversely affect native fauna through competition for food and nesting or roosting areas, through predation and by adversely affecting fauna habitat though soil disturbance and changing vegetation composition. Pest species may also create health and nuisance risks to adjacent landholders.
7.2 Objectives • To prevent the introduction of new weed species on the site; • To prevent the spread of existing weed species on the site; • To prevent the creation of habitat suitable for pest species; and • To minimise the occurrence of feral animals visiting or residing in the site.
7.3 Applicable Legislation, Policies and References The following legislation applies to weed and pest species management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Territory Parks and Wildlife Conservation Act 2000;• Weeds Management Act 2001;• Bushfires Act 2004;• Plant Diseases Control Act 2000; and • Soil Conservation and Land Utilization Act 2001.
Relevant policies, codes of practice and measures include: • Article 20 of the World Health Organisation Regulation; and
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• NT Medical Entomology Branch Guidelines. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Waste Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Fire Management Sub-plan are related to this Sub-plan.
7.4 Risk Assessment Table 9: Risk Assessment for Weeds and Pest Species
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Weed establishment from vegetation clearing and soil disturbance
4 2 8 L
Introduction of weed species from introduction of off-site soil and mulch
4 2 8 L
Weed establishment or spread
Introduction of weed species from vehicles travelling across site
4 2 8 L
Increased mosquito breeding as result of artificial ponding
3 3 9 LPest species
Loss of native invertebrates due to non-selective mosquito fogging
3 3 9 L
Introduction of feral species
Feral species (including domestic dogs) interfering with site operations
2 2 4 L
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7.5 Management Actions – Weeds and Pest SpeciesEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Imported fill must be certified weed free beforebeing brought on site
Contractor
All vehicles or excavation equipment entering thesite must be visually inspected and cleared of anysoil/vegetative matter prior to entry
Contractor Personnel to undertakeinspection
No introduction of new weedspecies
Topsoil stripped from weed-infested areas may beladen with weed seeds and must be removed fromsite or treated to prevent introducing weeds intocurrently weed free areas
Contractor
Weed control
When working in weed infested areas, ensurevehicles and equipment are inspected and allvegetative matter (including seeds) are removedprior to moving to weed-free areas
Contractor Personnel to undertakeinspection
No increase in areas of weedinfestation
No domestic animals to be brought on to the site Contractor No domestic animals on siteWaste to be controlled so as not to encouragescavenger species to siteEnsure putrescible bins are covered and no wasteis left uncoveredMaintain a clean and tidy work area to ensurescavenger birds are not attracted to the site
ContractorPower & Water
Management of wastedisposal facilities
No problems with scavengerspecies
Pest speciesmanagement
Prevent the creation of areas and structures inwhich water could be retained and used formosquito breeding
Contractor Site inspection duringconstruction phases
No ponding of water
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaUse amber or cool white external lights oninfrastructure to minimise attracting pest species
ContractorPower & Water
Fence SAT basins to prevent domestic animalsand stock access to site
Power & Water Rabbit-proof fencing,including maintenance
Pest speciesmanagementcontinued
If increase in population of feral animals –undertake an eradication programme
DBIRD/Power &Water
Inspection of the site toensure feral animals have nottaken up residence on site
Removal of feral animals,such as rabbits from the siteand no increase in number ofother feral species, such asfoxes
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8 FIRE MANAGEMENT SUB-PLAN 8.1 Issues and Impacts Currently the AZRI site has a well-maintained network of firebreaks and access tracks (minimum 4 m wide) located around the perimeter. The potential impacts of uncontrolled fire as the result of construction activities include: • Creation of weed corridors; • Disruption of the current fire management regime; • Loss of existing vegetation and fauna habitat; • Disruption of the construction timetable; and • Potential for injury to construction workers or other community members.
8.2 Objectives • To prevent uncontrolled wildfire on the site; • To ensure safety of site personnel, surrounding residential areas; and • To protect native vegetation from the impact of hot wildfires.
8.3 Applicable Legislation, Policies and References The following legislation applies to fire management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999; and • Bushfires Act 2004.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Weed and Pest Species Management Sub-plan are related to this Sub-plan.
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8.4 Risk Assessment Table 10: Risk Assessment for Fire Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of construction infrastructure, assets and timeline
3 4 12 M
Weed establishment after fire disturbance 3 3 9 L
Fire
Loss of existing vegetation and fauna habitat 2 3 8 L
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8.5 Management Actions – FireEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Continue with the current policy of fire preventionused on AZRI which includes coordinating with thevolunteer and regular fire-fighters
Update current fire preventionpolicy for new activitiesundertaken on SAT site
Continue maintenance of fire breaks around AZRIsite
DBIRD/Power &Water
Maintenance of firebreaks onannual basis
Prevent the use of open firesEstablish new internal firebreaks at strategiclocations surrounding SAT basins if not alreadypresent
Fire management plan andconsultation with DBIRD
All site personnel are to be inducted into fire risk,prevention and management
Fire management
Have fire fighting equipment in strategic locationsacross site and in vehicles
ContractorPower & Water
Induction and training of sitepersonnel
No increase in incidence ofwildfireWildfires not originating fromAZRI siteFirebreaks maintainedPersonnel aware of firemanagement techniques
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9 HERITAGE MANAGEMENT SUB-PLAN 9.1 Issues and Impacts The SAT operational area has no archaeological or heritage sites. However, a survey conducted of the AZRI site (Crassweller, 2004) revealed 10 artefact scatters were located along creek and drainage line and on the flat plains. Impacts on cultural and heritage values associated with the site activities in the area may result from workforce members moving outside of the construction area.
9.2 Objectives • To minimise the impact on cultural sites, values and artefacts during construction activities; • To manage any newly discovered heritage objects appropriately; and • To minimise damage to significant trees, landscapes or artefacts.
9.3 Applicable Legislation, Policies and References The following legislation applies to heritage management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Aboriginal and Torres Strait Islander Heritage Protection Act 1984;• Northern Territory Aboriginal Sacred Sites Act 2004;• Aboriginal Land Act 2004;• Heritage Conservation Act 2000; and • National Trust (Northern Territory) Act 2001. Relevant policies, codes of practice and measures includes: • The Northern Territory Procurement Code (National Code of Practice for the Construction
Industry adapted for specific application in the Northern Territory). Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 138 to 140; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Vegetation, Fauna and Habitat Management Sub-plan and Access and Public Safety Sub-plan are related to this Sub-plan.
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9.4 Risk Assessment Table 11: Risk Assessment for Heritage Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Disturbance of Indigenous Heritage values 2 2 4 IDisturbance of European Cultural Heritage values 2 2 4 ILoss of or disturbance to significant trees 4 4 12 M
Loss of heritage and cultural values
Disturbance to significant landforms 3 3 9 L
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9.5 Management Actions – HeritageEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Identify areas that have cultural and heritage valuesprior to construction works being undertaken
Prepare map of areas ofcultural and heritagesignificance
Permission must be obtained from AAPA andconsultation should be undertaken with landcustodians prior to tree clearing on sitePermission must be obtained from Office ofEnvironment & Heritage to disturb artefacts
DBIRD
Seek permissions
If indigenous artefacts are found during constructionoperations, the operation will cease and SiteManagement and DBIRD project manager will benotified immediately
ContractorPower & Water
Communication with AAPA,Office of Environment &Heritage and land custodians
No artefacts or significant sitesare disturbed or damagedwithout prior approval
Confine earth moving vehicles, and workersvehicles to set parking areas (on existing serviceroads and tracks) to minimise the potential toimpact on significant trees and areas
ContractorPower & Water
No vehicles parked invegetated areas
Undertake cultural awareness training of theworkforce
ContractorPower & Water
No work is to be conducted outside of intendedconstruction area
ContractorPower & Water
Heritage management
If required, fence off significant areas. This shouldonly occur with permission of AAPA and the landcustodians.
ContractorPower & Water
Provide cultural awarenesstraining to site personnel
No artefacts or significant sitesare disturbed or damagedwithout prior approval
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10 AIR QUALITY MANAGEMENT SUB-PLAN 10.1 Issues and Impacts Air quality issues can occur as the result of construction activities. These include: • Nuisance dust produced from vehicle movement on site, earthworks and exposed soil
surfaces which can potentially cause: o Airborne dust to settle on employee vehicles; o Health (respiratory) issues for workers and adjoining site users (including
neighbouring residential area); o Dust to settle on the local drainage channels increasing turbidity and reducing the
transfer of oxygen between air and water; and • Occupational dust nuisance produced by construction activities can impact on workers and
adjoining land users, from inhalable and respirable dust, which can potential impact on their health and well-being.
10.2 Objectives • To manage air emissions from the construction site, particularly nuisance dust; • To comply with air quality standards as defined by Commonwealth and Northern Territory
legislation; and • To minimise greenhouse gas emissions.
10.3 Applicable Legislation, Policies and References The following legislation applies to air quality management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Ozone Protection Act 1990;• Dangerous Goods Act 1981;• Waste Management and Pollution Control Act 1998; and • Work Health Act 1986.
Relevant policies, codes of practice and measures include: • National Health and Medical Research Council (NHMRC) Guidelines for Air Quality; • National Exposure Standards for Atmospheric Contaminants in the Occupational
Environment (NOHSC, 1003); • Air Quality Standards AS/NZS 3580.10.1:2003 - Methods for sampling and analysis of
ambient air; • Australian Standard AS2985-2004 workplace atmospheres-method for sampling and
gravimetric determination of respirable dust; • Australian Ventilation Standard AS 1666.2; and • Occupational Health and Safety Regulations and advisory standards.
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Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soil Management Sub-plan, Hazardous Substance Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Access and Public Safety Management Sub-plan are related to this Sub-plan.
10.4 Risk Assessment Table 12: Risk Assessment for Air Quality Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Nuisance dust impacting on nearby residences 5 3 15 HNuisance dust impacting on site workers 5 3 15 HImpact from nuisance dust on adjacent vegetated areas
3 2 6 L
Dust
Increasing turbidity and reducing the transfer of oxygen between air and water from dust settling on the local drainage channels
2 2 4 I
Greenhouse gases
Production of greenhouse gas emissions 5 1 5 I
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10.5 Management Actions – Air QualityEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Restrict movement on boundary firebreaks to thatrequired for AZRI property management
Regular road and trackmaintenance
High use roads should be constructed to minimisedust generation
Maintenance of access roads
A maximum speed limit of 20 km/h will be imposedwithin the site to control generation of dust byvehicles moving through operation areas
Meets the NHMRC Guidelinesfor Air Quality
Daily assessment of weather conditions Register of daily windconditions
During periods of high winds when soil moisture islow, additional precautions will need to beundertaken to protect exposed surfaces. Thesemay include increased frequency of watering andcessation of site operations during strong windswhich are likely to mobilise soils and dust,especially if winds are blowing towards sensitivereceiving areas (i.e. residential area)
Management ofnuisance dustemissions
Ensure all exposed soils are stabilised e.g. usingmulch to assist with dust suppression
ContractorPower & Water
Mulching machine
Dust generating activitiesceased or suppressionmeasures implemented whenstrong winds present
Record any dust complaints ContractorPower & Water
Maintain a dust complaintsregister
No dust complaints
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaIf undertaking dust producing activities (sanding,grinding, welding) during construction of SATfacilities, engineering measures or PersonalProtective Equipment (PPE) must be used
Management ofoccupational dustemissions
Dust management on exposed soil surfaces,including onsite access tracks and stockpile sites,to be undertaken to reduce impact from airbornedust
Contractor PPE to be supplied to sitepersonnel
No dust complaintsMeets the National ExposureStandards for AtmosphericContaminants in theOccupational Environment(NOHSC, 1003)
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11 NOISE MANAGEMENT SUB-PLAN 11.1 Issues and Impacts During construction activities, noise levels above the background noise may be generated from plant and equipment used in excavation and construction. Construction activities that can cause noise include: • The installation of extraction and monitoring wells; • The clearing of land for infrastructure development; and • The building of infrastructure. The impact of noise on neighbouring residents will be largely dependent on the time of day noise is created and the direction of wind.
11.2 Objectives • To minimise noise emissions during construction activities; • To minimise noise emissions impacting on the adjacent residential area and other sensitive
receivers; and • To comply with relevant noise standards.
11.3 Applicable Legislation, Policies and References The following legislation applies to noise management: • Waste Management and Pollution Control Act 1998; and • Work Health Act 1986.
Relevant policies, codes of practice and measures include: • Draft Waste Management and Pollution Control (Environmental Noise) Regulations; • Australian Standard 2436-1981 Guide to Noise Control on Construction, Maintenance and
Demolition Sites; • Occupational Noise National Code of Practice; and • Occupational Health and Safety Regulations and advisory standards. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Access and Public Safety Management Sub-plan is related to this Sub-plan.
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11.4 Risk Assessment Table 13: Risk Assessment for Noise Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Noise from construction activities impacting on neighbouring residences resulting in noise complaints
5 3 15 HNoise
Impaired hearing of site personnel as the result of using noisy equipment
3 4 12 M
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11.5 Management Actions – NoiseEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Where possible, operate machinery and othervehicles, away from the residential area (westernside of site), between the hours of 1900 and 0700Machinery used at the site should be wellmaintained with high efficiency mufflers fitted to allsite equipment so that they conform to the NationalStandard for Occupational Noise (NOHSC: 1007(2000).Provide engineering measures to limit impact onworkforce using noisy equipment or providePersonal Protective Equipment whilst operating orworking near earthmoving equipment or othermachinery where required in accordance withnational standards
Maintenance of machineryPPE
Plant and EquipmentNoise
Record noise complaints
Power & WaterContractor
Maintenance of a noisecomplaints register
No noise complaintsMeets Occupational NoiseNational Code of Practice
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12 ACCESS AND PUBLIC SAFETY 12.1 Issues and Impacts There is a risk that visitors (authorised and unauthorised) may access the construction site. This can potentially create liabilities for SAT scheme management. The impacts associated with construction activities include: • Insecure areas may result in members of the public harming themselves; and • Insecure areas may result in operational equipment being damaged.
12.2 Objectives • To minimise impacts on site visitors (authorised and unauthorised); • To prevent unauthorised access of people; and • To prevent injury to site visitors.
12.3 Applicable Legislation, Policies and References The following legislation applies to access and public safety management: • Dangerous Goods Act 1981; and • Work Health Act 1986.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • SAT Operation Environmental Management Plan, Alice Springs Water Reuse Scheme. The Air Quality Management Sub-plan is related to this Sub-plan.
12.4 Risk Assessment Table 14: Risk Assessment for Access and Public Safety
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Vehicle accidents as the result of inappropriate site access points for entering and exiting site
3 3 9 L
Visitors (authorised and unauthorised) on site harming themselves
3 3 9 L
Site Access
Visitors (authorised and unauthorised) on site causing damage to operational equipment
3 3 9 L
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12.5 Management Actions – Access and Public SafetyEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Ensure site equipment is stored appropriatelyProvide fencing around site perimeter
Security measures, includingfencing
Access and publicsafety management
Develop a site OH&S Policy
Power & WaterContractor
Personnel to develop policy
No injuries or accidents duringconstruction activities
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13 INDUCTION TRAINING REQUIREMENTS The purpose of induction training is to ensure that all personnel who are engaged in the construction at the SAT site are aware of their environmental obligations. The Power and Water Corporation SAT scheme manager is responsible for the conduct of environmental induction training for all persons working on site, including any subcontractors. An experienced and qualified environmental trainer is to undertake environmental induction training for all personnel involved in the construction of the SAT site. It is proposed that the environmental induction training for site personnel and sub-contractors can be undertaken at two levels: 1. Complete induction - training for personnel who will be on-site for more than five days or
those personnel on-site for less than five days but involved in activities that have the potential to cause environmental harm (e.g. installation and maintenance of erosion and sediment control devices, clearing and grubbing, felling of trees, earthworks, stabilising disturbed surfaces); and
2. Quick induction - training for personnel that will be on-site for less than five days and are undertaking activities that do not have the potential to cause significant environmental harm.
An induction training programme for both induction levels needs to be developed. The induction training for both levels should cover the same issues. The difference between the two induction courses is the level of training provided for each issue. The issues to be addressed in induction include (but are not limited) to the following: • Awareness of SAT CEMP; • Awareness of general environmental duties under the relevant Acts and the consequences
of any breaches; • An overview of what constitutes an environmental incident and the appropriate person to
notify in the event of an environmental incident; • General awareness of the environmental and cultural significance of the adjacent local
drainage channels, vegetation corridors and buffer area; • Location of No Go areas, particularly St Mary’s Creek, the buffer area and recognised
cultural areas; • Specific practices required for erosion and sediment control; • Specific practices required for clearing and grubbing; • General flora and fauna management; • Appropriate locations for the parking of vehicles and machinery/plant equipment; • The need for off-site maintenance and wash down (if required) of construction vehicles; • Speed limit restrictions throughout the site; • Procedures to follow and who to contact in the case of a hydrocarbon or other hazardous
substance spill; • The location and use of fire extinguishers/hydrants; • Appropriate waste management practices; and • The appropriate person to notify in the event that any environmental mishaps occur. The environmental induction training can be undertaken alongside the OH & S training.
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14 MONITORING FRAMEWORK Monitoring is the systematic collection of data and information in relation to specific environmental issues or conditions. The main purposes of monitoring are: • To identify trends and changes over time and between areas to enable identification of
measures to improve environmental practices and performance; and • To assist in the identification of non-predicted impacts. There are two main areas that can be monitored, environmental condition and environmental management.
14.1 Environmental Condition Monitoring of environmental condition will establish whether the recommended practices in this EMP are effective in achieving their desired environmental outcome and will allow for the detection of non-predicted impacts. The principle issues requiring monitoring during the SAT construction relate to: • Changes to groundwater properties:
o Construction works for the SAT facilities have the potential to impact on the groundwater height and chemistry;
o Potential to cause contamination of groundwater as the result of accidental spills and or leakage of toxic or hazardous substances; and
o Compaction and excavation activities which are likely to occur during construction may cause the diversion of groundwater flow;
• Changes to surface water quality and quantity; • Change to vegetation structure and fauna habitats; • Complaints received from neighbouring properties from nuisance dust and excessive noise
caused by SAT construction activities; and • Increase in the number of mosquitoes/biting insects.
14.1.1 Groundwater Monitoring Although the monitoring strategy outlined below focuses on water quality changes during operational phases, it should be commenced during construction and then continued through the operational phases. This will provide baseline data on groundwater condition prior to the commencement of SAT construction and operation and horticultural construction and operation. Monitoring of the groundwater will be from four distinct levels within the subsurface: • Alluvial Layer 2: Within the more porous and permeable layer of sands and gravel to
typical depths of 3 m to 5 m; • Alluvial Layer 4: Within the more porous and permeable layer of silty sand and gravel
located above the main low permeability clay cap overlying the palaeochannel to typical depths of 9 m to 11 m;
• Alluvial Layer 6: Within both the main palaeochannel to depths of approximately 30 m and the more widespread layer outside the palaeochannel to depths of approximately 20 m; and
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• Tertiary Aquifers: Within the upper thin layers of sand material located at depths of approximately 50 m and greater below the overlying sequence of low permeability clays.
Monitoring these levels of groundwater will demonstrate that the objectives of enhanced water treatment, environmental protection and opportunities for reuse are achieved and will support the ongoing effective and efficient management of the SAT scheme. The monitoring bore network will be located in the following areas: • Immediately below the SAT infiltration basins (nominally four sets of bores); • Immediately adjacent to the SAT infiltration basins (nominally six sets of bores); • Adjacent to the aerial extent of the palaeochannel feature within the AZRI site around the
infiltration basins (nominally six sets of bores); and • Adjacent to the boundary of the AZRI site with the rural residential properties, Colonel
Rose Drive and Todd River and an equivalent distance to the west of the infiltration basins within the AZRI site (nominally eight sets of bores).
The migration of relatively saline groundwater down existing extraction bore annuli will also require monitoring and the most appropriate monitoring locations for this will be using the existing monitoring bores where access is available. The monitoring programme will include each of the existing Tertiary extraction wells located within the AZRI site and a representative selection of six extraction wells within the adjacent rural residential properties. A sampling and analysis programme will be established prior to the commencement of infiltration of recycled water in the SAT basins or use of recycled water in irrigation to measure ambient groundwater concentrations. The sampling and analysis programme will be undertaken for a suite of contaminants including major ions, metals and nutrients (Table 15). Table 15: Groundwater Monitoring during Commissioning Parameter Suggested Determinants Frequency of
testing per year Site(s)
Heavy Metals Al, As, B, Cu, Cd, Cr, Zn (as minimum suite)
4 Monitoring bores
Dominant ions Ca, Na, K, Cl, SO4, HCO3. 4 Infiltration ponds and monitoring bores
TDS Conductance (25°C). Calculation based on above.
12 Infiltration ponds and monitoring bores
Organics Pesticides, MBAS, TOC and DOC
2 Infiltration ponds and monitoring bores
Field determinations pH, turbidity, temperature, dissolved oxygen, ORP
52 Infiltration ponds and monitoring bores
Oxygen demand BOD, COD 12 Infiltration ponds and monitoring bores
Bacteriological indicators
Coliforms and E. coli 12 Infiltration ponds and monitoring bores
Pathogen indicators C. perfringens, viruses 4 Infiltration ponds and monitoring bores
Nutrients Total and dissolved P, Total N, TKN, NOx
4 Infiltration ponds and monitoring bores
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Use of sophisticated analysis systems such as polymerase chain reaction should be used to monitor for viruses of human concern, particularly coliphage variants.
14.1.2 Monitoring Soil Erosion During a rainfall event the risk for soil erosion to occur on site increases. Therefore it will be a requirement of the EMP to undertake regular monitoring of the surface water runoff from the site to determine if erosion control measures are required. If it is found that significant levels of sediments are moving off-site, sediment control measures, i.e. silt fencing and temporary sediment retention basins, should be installed.
14.1.3 Dust, Noise and Odour Complaints Monitoring Dust, noise and odours are not expected to adversely impact on neighboring stakeholders as long as construction activities are carried out with the relevant safeguards identified in this EMP. A complaints register should be established and complaints investigated. The complaints register should report the following information: • Date and time of complaint; • Date and time of incident; • Location; • Weather data to determine wind speed and direction to assist in identifying source of
nuisance; • Type of complaint – noise, dust or odour; • Description of complaint; • Contact details of complainant; • Who recorded complaint; • Who was responsible for investigating complaint; and • Results and outcome for investigation and follow up. If all safeguards and control measures for noise, dust or odours fail and complaints have been received, monitoring of these emissions should be undertaken. The monitoring activities for dust, noise and odour are described below: • Dust monitoring will be undertaken following the Air Quality Standards AS 3580.10.1:2003 -
Methods for sampling and analysis of ambient air. The siting of the air sampling units will require one in the location of the complainant and a background unit located upwind of the SAT site;
• Environmental noise monitoring will be undertaken in accordance with the AS 1055.1:1997 Acoustics—Description and measurement of environmental noise, which sets out general procedures for the description and measurement of environmental noise including repetitive impulsive noise and AS 1055.2:1989 Application to specific situations; and
• Monitoring odour is slightly more difficult, as odour recognition is a sensation resulting from the reception of a stimulus by the olfactory sensory system. The human response to an odour is only able to be evaluated depending on the particular sensory property that is being measured, including the intensity, detectability, character, and hedonic tone of the odour. The combined effect of these properties is related to the annoyance that may be caused by the odour. Therefore if a number of complaints are received from the adjacent residential area (approximately 10% of the effected population) measures will be
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undertaken to identify the source of the odour and investigate ways to mitigate and manage.
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14.1.4 Vegetation, Habitat and Fauna monitoring Prior to clearing activities at the SAT site, it is recommended that a targeted survey of the area be undertaken to ascertain the presence or absence of Threatened species. In the event that such species are located, further consideration of their management will be required. For example, if it is a Threatened fauna species, options for relocation (and subsequent survival after relocation) would need to be investigated. If it is a Threatened flora species, options for seed collection and propagation should be investigated (relatively few native flora species survive translocation). Monitoring of weeds and pest species on site should be undertaken on a regular basis (quarterly) to ensure that construction activities are not exacerbating the current weed problems or increasing the number of feral species present. Weed control should be undertaken as part of an annual weed control programme. Only mechanical or physical control should be used at the SAT site, to prevent herbicide entering the basins.
14.1.5 Mosquito / Biting Insect Monitoring During the construction phase of the SAT scheme, it is unlikely that mosquito populations will increase as the construction phase does not involve creation of water-bodies in which mosquito breeding can occur. For this phase, monitoring should focus on prevention of ponding areas, particularly if vegetation is also present, to prevent the creation of breeding habitat.
14.2 Environmental Management In addition to monitoring environmental conditions, it is also important to monitor the development and implementation of the environmental management processes within the construction activities of the SAT scheme. Environmental management is the process by which the construction manager can ensure compliance to environmental legislation and minimise environmental risks. Environmental management monitoring for the construction activities will include: • Periodic reviews and auditing of construction to ensure recommended activities are being
carried out; and • Periodic reviews and audits of construction activities to ensure the management action
tables provided in this EMP are being used as a checklist for ensuring all environmental management measures are being implemented.
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15 AUDITING Environmental auditing is an integral part of the environmental management of the construction activities for the SAT scheme. It is an important management tool that is a systematic, documented, periodic and objective evaluation of the environmental management practises on site. The audit assists in verifying how well the operation is performing against the CEMP and processes, to determine the level of compliance with the nominated environmental criteria. Environmental auditing should be seen as an opportunity for the continual improvement of management practises at the site. It should also be conducted during any or all stages of the proposed activities and can be undertaken in conjunction with other system audits, such as workplace health and safety, quality and contract administration, or it can be undertaken as a separate environmental audit.
15.1 Periodic Review Periodic reviews during construction of the SAT facilities will be required to ensure the measures set in the CEMP are being implemented. The periodic review will be undertaken by the relevant responsible bodies as described in the management sub-plans. The periodic review of construction activities will be undertaken in the form of an informal inspection. The objectives of the review are to identify: • Physical aspects of the construction activities which are not in compliance with the set
requirements of this CEMP; and • Any aspects of the construction activities that may have caused or have the potential to
cause environmental harm, including impacts that have not been predicted or addressed. While these inspections will be less rigorous than actual environmental audits, they play an important role in identifying non-conformances that may require immediate remedial action. These inspections can also be important mechanism for identifying areas that may need to be audited in the future. The informal inspections should be undertaken throughout the life of the construction activities at least once per week (depending on the activities taking place on site); particularly during key developmental stages or activities, such as: • Prior to commencement of works; • During and at the completion of basin construction; • During heavy rainfall events to monitor runoff from site; and • During clearing of vegetation.
15.2 Environmental Audit It is recommended that environmental audits will be undertaken within the first couple of weeks of construction activities and at the completion of construction. Compliance audit will be the primary audit undertaken during construction which is similar to the periodic review only it is more thorough and the audit will be conducted by someone external to the process. The audit can be undertaken by relevant, trained members of an organisation’s own staff (i.e. Environmental Officer) or by external, professional auditor.
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15.3 Non-conformance Procedures Non-conformance procedures are those procedures that should be followed in the event that a site audit or inspection identifies a breach of the agreed environmental management strategies has occurred. These procedures apply to all personnel including any sub-contractors. In the event of a non-conformance, the following procedures should be followed: • The non-conformance activity should cease; • The Construction Manager should be contacted, who will then contact the Environment
Manager, Safety Officer or other personnel as required; • Assess the degree of non-conformance and extent of resultant environmental impact (if
any); • Determine procedures for mitigation or management; and • Undertake management or mitigation procedures to the satisfaction of the Environment
Officer. Each non-conformance should be documented, along with the corrective actions undertaken.
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Appendix 8: Construction Environmental Management Plan Horticulture Scheme
Horticulture Construction Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005
Prepared for: Power and Water Corporation PO Box 1521 Alice Springs NT 0871 Report by: HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia Ph: +61 8 8935 0515 Fax: +61 8 8932 5369 HLA Ref: B600270_RPT_Final_HortCEMP_11Apr05.doc
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DISTRIBUTION Horticulture Construction Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005
Copies Recipient Copies Recipient 1 Mark Skinner
Senior Project Officer PO Box 1521 Alice Springs NT 0871
This document was prepared for the sole use of Power and Water Corporation and the regulatory agencies that are directly involved in this project, the only intended beneficiaries of our work. No other party should rely on the information contained herein without the prior written consent of HLA-Envirosciences Pty Limited and Power and Water Corporation.
By HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia
____________________________________ Alana Eggleton Environmental Scientist
Peer Review: Date:
11 April 2005
Dr Sandy Griffin Principal Environmental Scientist
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CONTENTS 1 THE HORTICULTURE CONSTRUCTION EMP............................................................ 1
1.1 Introduction ..................................................................................................... 1 1.2 Background..................................................................................................... 1 1.3 Purpose........................................................................................................... 2 1.4 Risk Assessment ............................................................................................ 2 1.5 Management Strategies.................................................................................. 3
2 SOILS AND EROSION MANAGEMENT SUB-PLAN................................................... 4 2.1 Issues and Impacts......................................................................................... 4 2.2 Objectives ....................................................................................................... 4 2.3 Applicable Legislation, Policies and References ............................................ 4 2.4 Risk Assessment ............................................................................................ 5 2.5 Management Actions - Soils and Erosion....................................................... 6
3 WATER MANAGEMENT SUB-PLAN ........................................................................... 9 3.1 Issues and Impacts......................................................................................... 9 3.2 Objectives ....................................................................................................... 9 3.3 Applicable Legislation, Policies and References ............................................ 9 3.4 Risk Assessment .......................................................................................... 10 3.5 Management Actions – Water ...................................................................... 11
4 WASTE MANAGEMENT SUB-PLAN ......................................................................... 13 4.1 Issues and Impacts....................................................................................... 13 4.2 Objectives ..................................................................................................... 13 4.3 Applicable Legislation, Policies and References .......................................... 13 4.4 Risk Assessment .......................................................................................... 14 4.5 Management Actions – Waste...................................................................... 15
5 HAZARDOUS SUBSTANCES MANAGEMENT SUB-PLAN ..................................... 16 5.1 Issues and Impacts....................................................................................... 16 5.2 Objectives ..................................................................................................... 16 5.3 Applicable Legislation, Policies and References .......................................... 16 5.4 Risk Assessment .......................................................................................... 17 5.5 Management Actions - Hazardous Substances ........................................... 18
6 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN ...................... 19 6.1 Issues and Impacts....................................................................................... 19 6.2 Objectives ..................................................................................................... 19 6.3 Applicable Legislation, Policies and References .......................................... 19 6.4 Risk Assessment .......................................................................................... 20 6.5 Management Actions - Vegetation, Fauna and Habitat................................ 21
7 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN ..................................... 23 7.1 Issues and Impacts....................................................................................... 23
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7.2 Objectives ..................................................................................................... 23 7.3 Applicable Legislation, Policies and References .......................................... 23 7.4 Risk Assessment .......................................................................................... 24 7.5 Management Actions - Weeds and Pest Species ........................................ 25
8 FIRE MANAGEMENT SUB-PLAN .............................................................................. 27 8.1 Issues and Impacts....................................................................................... 27 8.2 Objectives ..................................................................................................... 27 8.3 Applicable Legislation, Policies and References .......................................... 27 8.4 Risk Assessment .......................................................................................... 28 8.5 Management Actions – Fire.......................................................................... 29
9 HERITAGE MANAGEMENT SUB-PLAN.................................................................... 30 9.1 Issues and Impacts....................................................................................... 30 9.2 Objectives ..................................................................................................... 30 9.3 Applicable Legislation, Policies and References .......................................... 30 9.4 Risk Assessment .......................................................................................... 31 9.5 Management Actions – Heritage .................................................................. 32
10 AIR QUALITY SUB-PLAN........................................................................................... 33 10.1 Issues and Impacts....................................................................................... 33 10.2 Objectives ..................................................................................................... 33 10.3 Applicable Legislation, Policies and References .......................................... 33 10.4 Risk Assessment .......................................................................................... 34 10.5 Management Actions – Air Quality ............................................................... 35
11 NOISE SUB-PLAN ...................................................................................................... 37 11.1 Issues and Impacts....................................................................................... 37 11.2 Objectives ..................................................................................................... 37 11.3 Applicable Legislation, Policies and References .......................................... 37 11.4 Risk Assessment .......................................................................................... 38 11.5 Management Actions – Noise....................................................................... 39
12 ACCESS AND PUBLIC SAFETY SUB-PLAN ............................................................ 40 12.1 Issues and Impacts....................................................................................... 40 12.2 Objectives ..................................................................................................... 40 12.3 Applicable Legislation, Policies and References .......................................... 40 12.4 Risk Assessment .......................................................................................... 41 12.5 Management Actions – Access and Public Safety ....................................... 42
13 INDUCTION TRAINING REQUIREMENTS................................................................. 43 14 MONITORING FRAMEWORK..................................................................................... 44
14.1 Environmental Condition............................................................................... 44 14.1.1 Groundwater Monitoring................................................................ 44 14.1.2 Monitoring Soil Erosion ................................................................. 46 14.1.3 Dust, Noise and Odour Complaints Monitoring............................. 46 14.1.4 Vegetation, Habitat and Fauna Monitoring.................................... 48
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14.1.5 Mosquito/Biting Insect Monitoring ................................................. 48 14.2 Environmental Management......................................................................... 48
15 AUDITING.................................................................................................................... 49 15.1 Periodic Review ............................................................................................ 49 15.2 Environmental Audit...................................................................................... 49 15.3 Non-conformance Procedures...................................................................... 50
TABLES Table 1: Measure of Likelihood ....................................................................................................3 Table 2: Measure of Consequence ..............................................................................................3 Table 3: Risk Assessment Scoring...............................................................................................3 Table 4: Risk Assessment for Soils and Erosion..........................................................................5 Table 5: Risk Assessment for Water Management Issues ........................................................10 Table 6: Risk Assessment for Waste Issues ..............................................................................14 Table 7: Risk Assessment for Hazardous Substance Issues.....................................................17 Table 8: Risk Assessment for Vegetation, Fauna and Habitat Issues .......................................20 Table 9: Risk Assessment for Weeds and Pest Species ...........................................................24 Table 10: Risk Assessment for Fire Issues ................................................................................28 Table 11: Risk Assessment for Heritage Issues.........................................................................31 Table 12: Risk Assessment for Air Quality Issues......................................................................34 Table 13: Risk Assessment for Noise Issues .............................................................................38 Table 14: Risk Assessment for Access and Public Safety.........................................................41 Table 15: Groundwater Monitoring during Commissioning ........................................................45
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1 THE HORTICULTURE CONSTRUCTION EMP 1.1 Introduction This Construction Environmental Management Plan (CEMP) has been prepared for the construction phase of a horticultural venture and associated infrastructure located at the Arid Zone Research Institute (AZRI), approximately 10 km south of Alice Springs, Northern Territory. The Public Environment Report (PER) Guidelines issued by the Office of Environment and Heritage (OEH) required the submission of EMPs to accompany the PER. This CEMP has been developed in accordance with the guidelines for the Alice Springs Water Reuse Scheme PER. A detailed description of the proposed Alice Springs Water Reuse Scheme is provided in the Public Environment Report, which accompanies this CEMP. This CEMP outlines the measures to manage the environmental integrity of the site during construction activities. The principal objective of the CEMP is to provide effective and practical management strategies that will avoid, ameliorate or mitigate potential adverse impacts associated with the proposed construction phase of the horticultural venture and the associated infrastructure. The CEMP includes clear instructions for management, monitoring and performance evaluation and are to be guided by the relevant legislation and other codes of practice.
1.2 Background It is proposed that a horticultural venture will be established within the AZRI site, using 1,000 ML per annum of recycled water and operate via a public/private partnership with a selected horticultural company. The proposal is for wastewater originating from the Alice Springs Wastewater Treatment plant to be pre-treated through a Dissolved Air Flotation system, piped to AZRI and then further treated through Soil Aquifer Treatment. Once the recycled water has been stored in the groundwater aquifer below, it is extracted and then used for irrigation. The horticulture scheme includes a plan to develop 20 ha per year in 4 ha operational blocks over five years, resulting in a total horticultural area of 100 ha. The horticultural site will include a range of basic operational infrastructure and utility services. Construction of the horticultural venture will potentially involve the following activities: • Finalisation of the layout of the horticultural area, including irrigation, fencing, buildings,
roads and services such as the electricity grid and town water supply; • Construction of temporary access tracks; • Vegetation clearing; • Preparation of the proposed 4 ha irrigation blocks. A general list of horticulture
construction methods is provided for potential crops; • General construction of perimeter fences and buildings as follows:
o perimeter fence to enclose the horticulture area (100 ha) and the buildings area (5 ha);
o Herbicide and/or insecticide and/or fertiliser sheds; o Sheds for fruit packing and cold storage rooms; o Sheds for maintenance and storage of tractors and implements;
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o Electric bore pump enclosure/s and electric irrigation pump enclosure/s; o Diesel storage tank; and o Manager’s house;
• Access road and staff car park; • Establishment of 50 m odour buffer zones between residential areas and the sub-surface
drip-irrigated area, 100 m odour buffer zones between residential areas and the recycled water holding area, and a 50 m noise buffer zone between residential areas and the bore pumps, irrigation pumps and cold rooms;
• Construction of waste management facilities, including waste stream from all processes (crop types to be finalised, details for construction purpose are based on a general list for each potential crop). All organic material waste from the fruit packing system will be composted on site and re-incorporated with the soil under the irrigated plants;
• Construction and design of irrigation well layout (nominal capacity requirements) including irrigation drilling methods, target depths etc. required;
• Irrigation setup for application of recycled water and access to recycled water supply, to employ the most efficient method of irrigation and/or soil treatment for minimizing salinity impacts; and
• Landscaping and revegetation at completion of activities in cleared areas where appropriate.
1.3 Purpose The horticultural CEMP aims to: • Provide details of proposed measures to prevent or minimise adverse impacts and assess
the likely effectiveness of these safeguards; • Ensure that safeguards are being effectively applied; • Enable remedial action for any impacts that were not anticipated in the PER; • Determine the differences between predicted and actual impacts (via monitoring); and • Provide for the periodic review of the management plan itself. The CEMP provides an ongoing interactive process for defining, documenting and improving the environmental management during the construction phase of the horticultural scheme. The CEMP is intended to be a ‘living’ document which allows for it to be continuously updated, reflecting feedback from the reporting conducted under the plan and recommendations arising from audits undertaken during construction. This CEMP is accompanied by an Operation EMP (OEMP) which addresses the management of environmental impacts associated with operational activities.
1.4 Risk Assessment A risk assessment, based on AS4360:1999 Risk Management, was undertaken on the potential environmental incidences that may arise during the construction activities for the horticultural scheme. The risk assessment combines (qualitative) estimates of the likelihood of a certain event or environmental impact occurring (Table 1) and the consequence (Table 2).
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Table 1: Measure of Likelihood Level Descriptor Description
1 Rare Environmental impact may occur only in exceptional circumstances 2 Unlikely Environmental impact could occur at some time based on current
practices 3 Moderate Environmental impact has a moderate probability of occurring based
on current practices 4 Likely Environmental impact will probably occur based on current practices 5 Almost Certain Environmental impact is expected to occur in most circumstances or
is already occurring
Table 2: Measure of Consequence Level Descriptor Description
1 Insignificant Negligible short term environmental impact to habitat with no monitoring required
2 Minor Some short term environmental disturbance with localised impacts, some management required
3 Moderate Obvious environmental impact to habitat, more widespread effects, normal incident management response is sufficient
4 Major Substantial environmental harm, loss of immediate habitat, widespread side effects over extended time, long term remediation management required, external agencies utilised
5 Catastrophic High degree of environmental harm, permanent loss of widespread habitat, loss of species, external agencies utilised, incident of regional significance
The likelihood of an event occurring is multiplied by the environmental consequence in order to determine the significance of the impact and, hence, its priority for management (Table 3). Table 3: Risk Assessment Scoring
Score Management required 25 Extreme risk: immediate action required to intervene and prevent incident.
15 – 20 High risk: prompt senior management attention of potential environmental impact. 10 – 14 Moderate risk: high priority issue requiring regular management and monitoring. 6 – 9 Low risk: low priority issue that can be managed by routine procedures 1 – 5 Insignificant risk: issue of low importance not requiring management but only
occasional monitoring.
The results of the risk assessment have been provided in each aspects sub-plan.
1.5 Management Strategies The following sections provide a description of each aspect or activity that has the potential to impact on the environment and strategies for the management of these potential impacts. Reference has been made to the appropriate section of the PER, where appropriate.
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2 SOILS AND EROSION MANAGEMENT SUB-PLAN 2.1 Issues and Impacts Soil management during construction of the horticultural infrastructure will primarily focus on soil erosion issues. All construction activities involving vegetation clearing and soil excavation have the potential to create soil erosion through wind or rain. The primary soil issues are: • Soil erosion – potential for disturbed soils and fill to be transported by surface flow during
rainfall events and/or onsite water usage or during periods of strong winds; • Dust generation - potential for vehicle movement or strong winds to cause loose soil (dust)
to be transported off-site; • Pollution of soils through spillage of oils, lubricants, fuels and other hazardous compounds
used by construction vehicles and machinery; • Top soil –topsoil removed during site works, which could possibly be used in a later phase
of construction, may need to be stockpiled on the horticultural site. During a rainfall event, topsoil may be washed into local drainage channels causing sedimentation or it may be a source of dust during periods of strong winds;
• Compaction - heavy vehicles moving on site may cause soil compaction. Compaction of soil may impact on the ability of plants to grow after site works as well as affect soil permeability; and
• Site fill – fill material has the potential to contain weed seeds and other contaminants (e.g. plant pathogens). If fill is stockpiled on site it has the potential to create dust hazards.
2.2 Objectives • To prevent degradation of soil at the site; • To minimise soil erosion across the horticultural site; • To minimise dust impacts from construction activities; • To minimise the potential for sediment transfer to St Mary’s Creek; and • To provide measures for the restoration of any degraded areas.
2.3 Applicable Legislation, Policies and References The following legislation applies to soil and erosion management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Soil Conservation and Land Utilization Act 1980;• Water Act 1992; and • Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures include: • The Northern Territory Procurement Code (National Code of Practice for the Construction
Industry adapted for specific application in the Northern Territory); and • National Environmental Protection (Assessment of Site Contamination) Measure 1999.
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Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 59 to 77; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Vegetation, Fauna and Habitat Management Sub-plan, the Air Quality Sub-plan and the Access and Public Safety Sub-plan are related to this Sub-Plan.
2.4 Risk Assessment Table 4: Risk Assessment for Soils and Erosion
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Accelerated erosion from vehicle movement on site during construction activities
4 3 12 MErosion of soil
Sedimentation of St Mary’s Creek should rainfall events occur during the construction phase, causing loose soil to be washed into the creek channel
2 4 8 L
Generation of dust by vehicle movement and general construction operations (i.e. clearing, site works, excavation for irrigation lines)
3 3 9 LCreation of Dust
Dust settling on water in local drainage channels, increasing turbidity and reducing transfer of oxygen from air to water
3 4 12 M
Pollution of Soils Spillage or leaks of oils, lubricants, fuels or other hazardous substances used by construction machinery
3 3 9 L
Compaction Changes to soil structure and permeability as a result of compaction from construction vehicles
4 2 8 L
Introduction of Soil Pathogens and Weeds
Potential for introduction of pathogens and/or weeds through the importation of fill for construction activities
3 3 9 L
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2.5 Management Actions - Soils and ErosionEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Ensure roads and tracks, as well as all builtinfrastructure, incorporate drainage controls tocontain and control water runoff during rainfallevents
Contractor Regular audit/ inspection ofthe site to ensure measuresare being implemented andare effective
During rainfall events, monitor the surface waterrunoff to determine whether erosion controlmeasures are effective. If it is found that significantlevels of sediments are flowing into St Mary’s Creekor other drainage channels, sediment controlmeasures, i.e. silt fencing and temporary sedimentretention basins, should be installed
Horticulturalist Inspection of runoff fromhorticultural site for anysignificant movement ofsediments near fence line ordrainage lines
Water erosionprevention strategy
Avoid placing stockpiles near boundary ofhorticultural site to limit the impact of runoff fromsite
Contractor Provide designated area forsoil stockpiling wheremeasures can be taken tominimise impact onsurrounding environment
No increase in movement ofsurface sediment off-site
If strong winds are blowing towards residentialareas all dust producing activities shall beminimised
ContractorHorticulturalist
Daily assessment of weatherconditions (particularly windspeed), dust generation andactivities causing dustgeneration
Wind erosion preventionstrategy
If excessive dust is noted, exposed road surfacesshall be wet down using water cart or sprinklersystems as required
Contractor Instigate a dust monitoringprogrammeDevelop a complaints registerto record any dust complaints
Dust results are withinrelevant environmental dustcriteria (NEPM)No dust complaints
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaVehicles must travel at <20 km/hr over unsealedroads to keep dust levels down
ContractorHorticulturalist
Speed limit signageTraining of site personnel
Minimise vehicle access across site to thatnecessary
ContractorHorticulturalist
Training of site personnelAppropriate signage
Restrict movement on boundary firebreaks to thatrequired for AZRI property management
ContractorHorticulturalist
Regular road and trackmaintenance
Design and construct roads to reduce dustgeneration
Contractor
Access tracks to be maintained to minimise fine,loose particulates
Horticulturalist Designated equipment andpersonnel for trackmaintenance
Minimise exposed soil surfaces within thehorticultural site
Horticulturalist
Revegetate disturbed areas not required to becleared for horticultural area (e.g. temporary fillstorage site)
Horticulturalist Implementation ofrevegetation strategy
Wind erosion preventionstrategycontinued
No soil stockpiles are to be left exposed on site ContractorHorticulturalist
Appropriate controls forminimising dust generation(i.e. cover with tarp or grassand locate downwind ofsensitive receiving areas(residential)
Dust results are withinrelevant environmental dustcriteria (NEPM)No dust complaints
Soil contaminationmitigation
Develop and implement appropriate waste disposaland fuel storage areas to current Australianstandards to minimise risk of spills and leaks
ContractorHorticulturalist
Bunded areas/containment orcontrol structuresRegular audits to ensurecompliance with EMP
No staining on surface soilaround fuel and otherchemical storage areas
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Environmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Provide procedures to manage fuel and otherchemical spills including use of fuel spill kits
Soil contaminationmitigationcontinued Provide appropriate containment and control
ContractorHorticulturalist
Training of site personnel torespond to incidencesDispose of hazardouschemicals and liquid wastes toan authorised landfillMaintain register of hazardoussubstances and fuels comingonto siteRegular audits to ensurecompliance with EMP
No staining on surface soilaround fuel and otherchemical storage areas
Limit the number of vehicles and earthmovingequipment travelling across site to what isnecessaryPrevent movement on or working of soils while wet
Training of site personnelRegular audit/ inspection ofthe site
Fit earthmoving equipment with low flotation tyres Appropriate tyres for vehicles
Compaction
Remediate any areas which have been impacted byrip/furrow/aeration of the impacted soils
ContractorHorticulturalist
Landfarming/landscapingequipment
No significant compaction ofsoils is occurring
If stockpile of soil or other materials occur on site,must be in conjunction with the site requirementsEnsure stockpile is stable by undertakingappropriate controls measures, i.e. cover with tarpor other stabilising agent
Stockpile management
Ensure stockpiles are >50 m from local residencesor drainage corridors
ContractorHorticulturalist
Provide a designated area forstockpiling
Dust results are withinrelevant environmental dustcriteria (NEPM)No dust complaints
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3 WATER MANAGEMENT SUB-PLAN 3.1 Issues and Impacts There are four main sources of water that exist or may be generated on site during the construction of the horticultural venture. These include: • Groundwater - the construction works of the horticultural operations has the potential to
impact on the groundwater height and chemistry. The contamination of groundwater may occur as the result of accidental spills and or leakage of toxic or hazardous substances. Compaction and excavation activities which are likely to occur during construction may cause the diversion of groundwater flow;
• Surface Water - generated through rainfall events or from using water during construction activities can result in contaminated surface waters running off into existing drainage areas. This has the potential to pollute surface water, through the movement of silt and other particulates and may also interfere with existing surface water flow patterns;
• Stormwater– stormwater runoff from the horticultural construction site which has been generated during periods of heavy rainfall or the general use of water on site may result in contamination of stormwater drains; and
• Wastewater – generated from wash down activities during construction. This may result in contamination of soil, groundwater, stormwater and surface water on site and off-site.
3.2 Objectives • To manage construction activities to prevent impact on groundwater systems aquifers by
contaminants or soil erosion; • To minimise potential impacts upon surface water, as a result of construction activities; and • To comply with legislative requirements.
3.3 Applicable Legislation, Policies and References The following legislation applies to water management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Water Act 1992; and • Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures include: • The Northern Territory Procurement Code (National Code of Practice for the Construction
Industry adapted for specific application in the Northern Territory); • National Environmental Protection (Assessment of Site Contamination) Measure 1999; and • Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 78 to 119; and
Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme
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• Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soils Management Sub-plan, Waste Management Sub-plan and Hazardous Products Management Sub-plan are related to this Sub-plan.
3.4 Risk Assessment Table 5: Risk Assessment for Water Management Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Contamination of groundwater from construction activity
2 2 4 I
Over-pumping of Bore water 2 2 4 I
Contamination and Alteration of Groundwater
Contamination of groundwater by drilling and installation of monitoring and test production wells
2 3 6 L
Surface water contamination due to soil erosion runoff
4 2 8 LContamination of Surface water
Contamination of surface water through fuel or chemical spills
3 2 6 L
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3.5 Management Actions – WaterEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Establish a groundwater monitoring programmeusing existing and new groundwater extractionbores. While construction activities are unlikely tohave a significant impact on groundwater,establishing monitoring prior to the operationalphase, will allow for baseline data collection
DBIRD Installation of groundwatermonitoring bores, drainagebores and barriersRoutine monitoring of waterfrom extraction boresResources to record andmanage analytical results
No adverse impact ongroundwater qualityNo significant change ingroundwater height
Site personnel vehicle and earthmoving equipmentshould park and move only on existing or newservice roads to minimise the compaction of soilsand the interruption of groundwater flows
No parking in vegetated areas
All construction equipment washdown will beconducted off-site
Induction for all constructionemployees
No washdown on site
Groundwatercontamination mitigation
Contain all accidental release or spills ofhydrocarbons and chemicals used duringconstruction activities
ContractorHorticulturalist
Provide spill kits No staining on surface soilaround fuel and otherchemical storage areas
Construction activities should be carried out duringthe dry season to reduce the risk for surfacewater/stormwater runoff
ContractorHorticulturalist
No major construction workduring peak rainfall period
During rainfall events, undertake regularinspections of drains and nearby sensitive receivingwaters to ensure they are not being undulyimpacted upon from sedimentation
Horticulturalist Regular inspections ofdrainage areas
No change in existing runoffpattern
Surfacewater/Stormwatercontamination mitigation
If required, establish erosion control measures, i.e.silt traps, retention basins, within identified runoffareas
ContractorHorticulturalist
Installation of erosion controlmeasures
No erosion occurring on site
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaSurfacewater/Stormwatercontamination mitigationcontinued
Contain all hazardous substances, fuels andchemicals, in appropriate areas (i.e. bunding,containment areas and control structures)
ContractorHorticulturalist
Maintenance of bunded areas,containment or controlstructuresDispose of waste chemicals toan authorised landfill whererequiredMaintain register of hazardoussubstances and fuels comingonto site
No incidences of fuel leaks orspillsNo staining on surface soilaround fuel and otherchemical storage areas
Any waste produced during construction activities(i.e. paint brushes, cement mixers, fuels and otherchemicals) should not be released onto ground orinto stormwater drains. Suitable hydrocarbon andchemical containment measures should beundertaken, such as portable bunding.Any waste water produced during constructionworks should be removed off-site to an approvedfacility
Wastewatermanagement practices
All construction equipment wash down is to occuroff-site
ContractorHorticulturalist
Undertake audits forcomplianceMaintenance of bunded areas,containment or controlstructures for all potentialgenerated wastewater
No adverse impact ongroundwater quality
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4 WASTE MANAGEMENT SUB-PLAN 4.1 Issues and Impacts Waste will be generated in the construction phase of the horticultural venture. The types of waste may include: • Rubble and excess soil; • Fuels, oils and lubricants; and • Organic waste from clearing operations.
The associated impacts from the generation of waste materials are: • Potential to attract fauna, such as birds, to the site because of uncovered organic
materials; • Increased number of disease carrying organisms such as flies and mosquitoes; • Potential to cause odours; • Stockpiling of inorganic material can impact on the visual amenities of the area; and • Rubble and other materials may block stormwater drains and cause sedimentation and
pollution within local drainage channels.
4.2 Objectives • To minimise the quantities of wastes produced during construction activities; • To ensure wastes are properly stored, transported and disposed from site; • To prevent impacts on the surrounding natural environment and on human health (i.e.
prevention of spills); and • To reduce, reuse and recycle wastes where possible.
4.3 Applicable Legislation, Policies and References The following legislation applies to waste management: • Waste Management and Pollution Control Act 1998;• Soil Conservation and Land Utilization Act 1980;• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Public Health Act 1981;• Dangerous Goods Act 1981; and • Environmental Assessment Act 1982.
Relevant policies, codes of practice and measures includes: • National Environmental Protection (Assessment of Site Contamination) Measure 1999. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and
Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme
B600270_RPT_Final_HortCEMP_11Apr05 14
• Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soil Management Sub-plan, Water Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan, Weed and Pest Species Management Sub-plan and Air Quality Management Sub-plan are related to this sub-plan.
4.4 Risk Assessment Table 6: Risk Assessment for Waste Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Pest attraction to organic wastes 4 2 8 LLoss of visual amenity 4 2 8 L
Generation of solid waste
Odours produced from putrescible waste materials 3 2 6 L
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4.5 Management Actions – WasteEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Provide putrescible waste bins for storage ofdomestic waste (i.e. food, paper, wrappers) prior toremoval from siteIf required, dispose putrescible wastes inappropriate storage bins and transport to aappropriately licensed green waste facilityPutrescible waste bins are to be covered at alltimes
Adequate Waste disposalfacilities on site (covered bins)Adequate transport of wastesoff-site to an approvedlicensed landfill facility whererequiredTraining of site personnel
Reuse vegetative matter from clearing operations inthe form of mulch and/or in landscaping orenhancement of buffers
Solid waste -putrescible materialscontrol
Vegetated waste can also be allocated to localcommunities for firewood if appropriate
ContractorHorticulturalist
Resources forlandscaping/enhancementwork
No odour complaintsNo loss of visual amenityReuse of vegetated materialon site rather than transfer tolandfill
Provide non-putrescible waste bins for storage ofdomestic waste (i.e. food, paper, wrappers) prior toremoval from siteSeparation recyclable wastes (paper andcardboard, other containers)
Provide adequate wastedisposal facilities (coveredbins), including separate binsfor recyclable materials
Solid wastes - non-putrescible materialscontrol
Non-recyclable wastes are to be transported to anapproved disposal facility (concrete, steel cut-offs,electric cables and general refuse)
ContractorHorticulturalist
Provide adequate transport ofnon-recyclable materials off-site
No litter located on site
Liquid waste control Ensure disposal of waste oils from vehicles,operational equipment and pumps is by a licensedwaste disposal contractor
ContractorHorticulturalist
Provide adequate transport ofwastes off-site by an approvedwaste disposal contractor
No on site disposal of liquidwastes
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5 HAZARDOUS SUBSTANCES MANAGEMENT SUB-PLAN
5.1 Issues and Impacts The principal issue associated with the use of hazardous substances for the construction of the horticulture facilities is: • Inappropriate use, handling and storage of hazardous products or chemicals that can result
in impacts on the surrounding environment, site workers, land users and the surrounding community.
The potential impacts on the environment include: • Contamination of groundwater and soil; • Contamination of surface water; and • Impacts on water quality and biological aspects of the area. The potential impacts on site workers, land users and neighbouring properties include: • Potential injury (long or short term) as a result of incorrect handling and storage
procedures; and • Potential legislative action as a result of incorrect handling and storage procedures.
5.2 Objectives • To prevent contamination of soil or water through spillage of hazardous substance; • To manage hazardous material storage, handling and disposal in a manner which
minimises the risk to the surrounding environment and for the safety of the employees and public; and
• To comply with legislation and regulatory requirements.
5.3 Applicable Legislation, Policies and References The following legislation applies to hazardous substance management: • Waste Management and Pollution Control Act 1998;• Dangerous Goods Act 1981;• Soil Conservation and Land Utilization Act 1980;• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Water Act 1992; and • Work Health Act 1986 and Regulations.
Relevant policies, codes of practice and measures include: • National Environmental Protection (Assessment of Site Contamination) Measure 1999;
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• National Code of Practice for the Control of Workplace Hazardous Substances (NOHSC:2007, 1994);
• Australian Standards for storage, handling and assessment of risks associated with hazardous substances;
• Storage and handling of hazardous substances in accordance with Northern Territory Work Health (Occupational Health and Safety) Regulations (as in force at 26 November 2003) Part 7; and
• Storage and handling of hazardous substances in accordance with National Code of Practice for the Control of Workplace Hazardous Substances (NOHSC:2007, 1994).
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Air Quality Sub-plan and Access and Public Safety Sub-plan are related to this plan.
5.4 Risk Assessment Table 7: Risk Assessment for Hazardous Substance Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Accidental fuel spills associated with construction and storage activities, facilities and wash down of vehicles
3 2 6 LHazardous materials management
Hazardous Materials - chemical usage and spills (i.e. chemicals, herbicides and pesticides)
3 2 6 L
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5.5 Management Actions - Hazardous SubstancesEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Hazardous chemicals used on site to be handledand stored in accordance with the National Code ofPractice for the Control of Workplace HazardousSubstances (NOHSC:2007, 1994)
Detailed hazardoussubstances management andstorage proceduresHandling, storage anddisposal of hazardoussubstance training for sitepersonnel
A register (stock inventory) and Material SafetyData Sheets (MSDS) must be available for allhazardous substances used during constructionactivities
MSDS records and incidentreporting
Develop an emergency spills procedure includingthe reporting of all spills and environmentalincidents to NT Department of Infrastructure,Planning and Environment through the WasteManagement & Pollution Control Register orPollution Response Line 1800 064 567
Training of constructionpersonnel in the use andstorage of hazardoussubstance and how to respondto a incident
Hazardous substances and chemicals are to bestored in approved containers, off groundBunding or other containment to be used forhazardous substances where requiredAny on-site machinery refuelling should be carriedout in an approved area where any spills and leaksof hazardous substances can be contained.
Hazardoussubstance/chemicalcontrols
Any spills that occur on horticultural lands must beremediate to the satisfaction of the regulatoryauthorities
ContractorHorticulturalist
Undertake regularaudit/inspections of the site toensure safety measures inhandling and storage ofhazardous substances arebeing implementedProvide bunded areas andother containment facilitiesand maintain
No accidental spills or leakageof hazardous substancesNo evidence of fuel or otherchemical residue from leakageor spills on siteAll personnel aware of spillsprocedures
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6 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN
6.1 Issues and Impacts There is a potential that construction activities for the horticultural facilities could impact on the vegetation and habitats surrounding the site and, subsequently, the native fauna in the area. The potential impacts that may occur include:
• Loss or alteration of habitat through clearing of vegetation; • Degradation of the adjacent vegetated areas through changes in hydrology and
compaction; • Disturbance to fauna on site through the creation of artificial fauna attractants, which may
result in harm to fauna, or interfere with construction activities; and • Loss of threatened fauna and flora from the area (either temporarily during site activity or
permanently); this can be the result of inappropriate clearing which can contribute to land degradation and the loss of biodiversity.
6.2 Objectives • To protect Threatened species or any area of environmental or cultural significance; and • To limit the impact upon habitat of native species through management practices.
6.3 Applicable Legislation, Policies and References The following legislation applies to vegetation, fauna and habitat management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Territory Parks and Wildlife Conservation Act 2000;• Weeds Management Act 2001;• Bushfires Act 2004;• Plant Diseases Control Act 2000; and • Soil Conservation and Land Utilization Act 2001.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Weed and Pest Management Sub-plan and Fire Management Sub-plan are related to this Sub-plan.
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6.4 Risk Assessment Table 8: Risk Assessment for Vegetation, Fauna and Habitat Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of vegetation 2 2 4 ILoss of Threatened species of flora or fauna 2 4 8 LDisturbance to fauna 3 3 6 L
Impact to vegetation, fauna and habitat
Loss of habitat 2 2 4 I
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6.5 Management Actions - Vegetation, Fauna and HabitatEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Minimise areas cleared during construction of thesite to that actually required for development of thehorticultural scheme
ContractorHorticulturalist
Ensure only nominated areas are targeted duringclearing activities
Contractor
No clearing of areas outside ofdesignated construction site
Retain large/mature trees and shrubs, whereverpractical, especially hollow-bearing River RedGums
ContractorHorticulturalist
Retention of environmentallyor culturally significant trees inlocations where they will notimpact on horticulturaloperations
Obtain permission to clear from AAPA (AboriginalAreas Protection Authority)
Horticulturalist
Clearing plan showing areasto be retained, boundaries ofconstruction site and bufferareas
Certificate of Authority issued
Use cleared vegetative matter to enhance buffers ContractorHorticulturalist
Personnel to undertake bufferenhancement
Confine parked earthmoving vehicles and workersvehicles to set parking areas (on existing serviceroads and tracks) to minimise the impact on nativeflora
Contractor Training of site personnel No parking in vegetated areas
Undertake targeted Threatened flora speciessurvey prior to commencement of clearing
ContractorHorticulturalist
Qualified botanist to undertakesurvey
Native floramanagement
If Threatened flora species located, develop, inconjunction with the Office of Environment &Heritage, a Threatened species managementprogramme
Horticulturalist Personnel to developmanagement strategy
No Threatened flora speciesdisturbed without adequateand approved controls in place
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaMaintain a clean and tidy work area to ensure thatnative fauna are not attracted to the constructionsite
ContractorHorticulturalist
Provide covered bins andminimise water ponding
No incidences of faunaattracted to waste
Use amber lighting as an alternative to white lightsto attract fewer insects which will reduce the chanceof attracting insect-eating fauna to the site (thisshould only occur where use of amber lighting doesnot conflict with OH&S requirements)
Horticulturalist
Retain large/mature trees and shrubs, whereverpractical, especially hollow-bearing River RedGums
ContractorHorticulturalist
Clearing plan showing areasto be retained, boundaries ofconstruction site and bufferareas
Retention of environmentallysignificant trees in locationswhere they will not impact onhorticultural operations
Enhancement of buffers to increase their value aswildlife corridors and habitat areas, using vegetativematerial cleared during construction
ContractorHorticulturalist
Personnel to undertake bufferenhancement
Undertake targeted Threatened fauna speciessurvey prior to commencement of clearing
ContractorHorticulturalist
Qualified zoologist toundertake survey
Native faunamanagement
If Threatened fauna species located, develop, inconjunction with the Office of Environment &Heritage, a Threatened species managementprogramme
Horticulturalist Personnel to developmanagement strategy
No Threatened fauna speciesdisturbed without adequateand approved controls in place
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7 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN
7.1 Issues and Impacts The introduction of weeds and pest species during the construction phase may cause environmental impacts to the project site. Weeds have the potential to: • Increase the risk of wildfire; • Compete with native plants and horticultural crops; • Change the micro-habitat; • Encourage an excessive use of herbicide use in weed control; and • Affect visual amenity. The introduction of weeds during the construction phase will possibly be by vehicles entering the site carrying seed and seed in any fill that is imported to the site. Additionally weed seed may be carried on to the site by wind and water movement or by animals. During the construction phase new and existing weed species may become more rapidly established because of the associated disturbed ground related to the construction activities. Pest species have the potential to adversely affect native fauna through competition for food and nesting or roosting areas, through predation and by adversely affecting fauna habitat though soil disturbance and changing vegetation composition. Pest species may also create health and nuisance risks to adjacent landholders.
7.2 Objectives • To prevent the introduction of new weed species on the site; • To prevent the spread of existing weed species on the site; • To prevent the creation of habitat suitable for pest species; and • To minimise the occurrence of feral animals visiting or residing in the site.
7.3 Applicable Legislation, Policies and References The following legislation applies to weed and pest species management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Territory Parks and Wildlife Conservation Act 2000;• Weeds Management Act 2001;• Bushfires Act 2004;• Plant Diseases Control Act 2000; and • Soil Conservation and Land Utilization Act 2001.
Relevant policies, codes of practice and measures include: • Article 20 of the World Health Organisation Regulation; and
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• NT Medical Entomology Branch Guidelines. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan, Fire Management Sub-plan are related to this Sub-plan.
7.4 Risk Assessment Table 9: Risk Assessment for Weeds and Pest Species
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Weed establishment from vegetation clearing and soil disturbance
4 2 8 L
Introduction of weed species from introduction of off-site soil and mulch
4 2 8 L
Weed establishment or spread
Introduction of weed species from vehicles travelling across site
4 2 8 L
Increased mosquito breeding as result of artificial ponding
3 3 9 LPest species
Loss of native invertebrates due to non-selective mosquito fogging
3 3 9 L
Introduction of feral species
Feral species (including domestic dogs) interfering with site operations
2 2 4 L
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7.5 Management Actions - Weeds and Pest SpeciesEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Imported fill must be certified weed free beforebeing brought on site
Contractor
All vehicles or excavation equipment entering thesite must be visually inspected and cleared of anysoil/vegetative matter prior to entry
Contractor Personnel to undertakeinspection
No introduction of new weedspecies
Topsoil stripped from weed-infested areas may beladen with weed seeds and must be removed fromsite or treated to prevent introducing weeds intocurrently weed free areas
Contractor
Weed control
When working in weed infested areas, ensurevehicles and equipment are inspected and allvegetative matter (including seeds) are removedprior to moving to weed-free areas
Contractor Personnel to undertakeinspection
No increase in areas of weedinfestation
No domestic animals to be brought on to the site Contractor No domestic animals on siteWaste to be controlled so as not to encouragescavenger species to siteEnsure putrescible bins are covered and no wasteis left uncoveredMaintain a clean and tidy work area to ensurescavenger birds are not attracted to the site
ContractorHorticulturalist
Management of wastedisposal facilities
No problems with scavengerspecies
Pest speciesmanagement
Prevent the creation of areas and structures inwhich water could be retained and used formosquito breeding
Contractor Site inspection duringconstruction phases
No ponding of water
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaUse amber or cool white external lights oninfrastructure to minimise attracting pest species
ContractorHorticulturalist
Fence horticultural area to prevent domesticanimals and stock access to site
Horticulturalist Rabbit-proof fencing, includingmaintenance
Pest speciesmanagementcontinued
If increase in population of feral animals –undertake an eradication programme
Horticulturalist Inspection of the site to ensureferal animals have not takenup residence on site
Removal of feral animals,such as rabbits from the siteand no increase in number ofother feral species, such asfoxes
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortCEMP_11Apr05 27
8 FIRE MANAGEMENT SUB-PLAN 8.1 Issues and Impacts Currently the AZRI site has a well-maintained network of firebreaks and access tracks (minimum 4 m wide) located around the perimeter. The potential impacts of uncontrolled fire as the result of construction activities include: • Creation of weed corridors; • Disruption of the current fire management regime; • Loss of existing vegetation and fauna habitat; • Disruption of the construction timetable; and • Potential for injury to construction workers or other community members.
8.2 Objectives • To prevent uncontrolled wildfire on the site; • To ensure safety of site personnel, surrounding residential areas; and • To protect native vegetation from the impact of hot wildfires.
8.3 Applicable Legislation, Policies and References The following legislation applies to fire management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999; and • Bushfires Act 2004.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Vegetation, Fauna and Habitat Management Sub-plan and Weed and Pest Species Management Sub-plan are related to this Sub-plan.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortCEMP_11Apr05 28
8.4 Risk Assessment Table 10: Risk Assessment for Fire Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of construction infrastructure, assets and timeline
3 4 12 M
Weed establishment after fire disturbance 3 3 9 L
Fire
Loss of existing vegetation and fauna habitat 2 3 8 L
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8.5 Management Actions – FireEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Continue with the current policy of fire preventionused on AZRI which includes coordinating with thevolunteer and regular fire-fighters
Update current fire preventionpolicy for new activitiesundertaken on horticulture site
Continue maintenance of fire breaks around AZRIsite
DBIRD
Maintenance of firebreaks onannual basis
Prevent the use of open firesEstablish new internal firebreaks at strategiclocations
Fire management plan andconsultation with DBIRD
All site personnel are to be inducted into fire risk,prevention and management
Fire management
Have fire fighting equipment in strategic locationsacross site and in vehicles
ContractorHorticulturalist
Induction and training of sitepersonnel
No increase in incidence ofwildfireWildfires not originating fromAZRI siteFirebreaks maintainedPersonnel aware of firemanagement techniques
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9 HERITAGE MANAGEMENT SUB-PLAN 9.1 Issues and Impacts During the construction phase there is there potential for heritage sites or artefacts to be impacted upon. The impacts could include disturbance to culturally significant artefacts, significant trees and significant landforms during construction activities.
9.2 Objectives • To minimise the impact on cultural sites, values and artefacts during construction activities; • To manage any newly discovered heritage objects appropriately; and • To minimise damage to significant trees, landscapes or artefacts.
9.3 Applicable Legislation, Policies and References The following legislation applies to heritage management: • Aboriginal and Torres Strait Islander Heritage Protection Act 1984;• Northern Territory Aboriginal Sacred Sites Act 2004;• Aboriginal Land Act 2004;• Heritage Conservation Act 2000; and • National Trust (Northern Territory) Act 2001.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 138 to 140; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme.
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9.4 Risk Assessment Table 11: Risk Assessment for Heritage Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Disturbance of Indigenous Heritage values 2 2 4 IDisturbance of European Cultural Heritage values 2 2 4 ILoss of or disturbance to significant trees 4 4 12 M
Loss of heritage and cultural values
Disturbance to significant landforms 3 3 9 L
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9.5 Management Actions – HeritageEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Identify areas that have cultural and heritage valuesprior to construction works being undertaken
Prepare map of areas ofcultural and heritagesignificance
Permission must be obtained from AAPA andconsultation should be undertaken with landcustodians prior to tree clearing on sitePermission must be obtained from Office ofEnvironment & Heritage to disturb artefacts
DBIRD
Seek permissions
If indigenous artefacts are found during constructionoperations, the operation will cease and SiteManagement and DBIRD project manager will benotified immediately
ContractorHorticulturalist
Communication with AAPA,Office of Environment &Heritage and land custodians
No artefacts or significant sitesare disturbed or damagedwithout prior approval
Confine earth moving vehicles, and workersvehicles to set parking areas (on existing serviceroads and tracks) to minimise the potential toimpact on significant trees and areas
ContractorHorticulturalist
No vehicles parked invegetated areas
Undertake cultural awareness training of theworkforce
ContractorHorticulturalist
No work is to be conducted outside of intendedconstruction area
ContractorHorticulturalist
Heritage management
If required, fence off significant areas. This shouldonly occur with permission of AAPA and the landcustodians.
ContractorHorticulturalist
Provide cultural awarenesstraining to site personnel
No artefacts or significant sitesare disturbed or damagedwithout prior approval
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10 AIR QUALITY SUB-PLAN 10.1 Issues and Impacts Air quality issues can occur as the result of construction activities. These include: • Nuisance dust produced from vehicle movement on site, earthworks and exposed soil
surfaces which can potentially cause: o Airborne dust to settle on employee vehicles; o Health (respiratory) issues for workers and adjoining site users (including
neighbouring residential area); o Dust to settle on the local drainage channels increasing turbidity and reducing the
transfer of oxygen between air and water; and • Occupational dust nuisance produced by construction activities can impact on workers and
adjoining land users, from inhalable and respirable dust, which can potential impact on their health and well-being.
10.2 Objectives • To manage air emissions from the construction site, particularly nuisance dust; • To comply with air quality standards as defined by Commonwealth and Northern Territory
legislation; and • To minimise greenhouse gas emissions.
10.3 Applicable Legislation, Policies and References The following legislation applies to air quality management: • Ozone Protection Act 1990;• Dangerous Goods Act 1981;• Waste Management and Pollution Control Act 1998; and • Work Health Act 1986.
Relevant policies, codes of practice and measures include: • National Health and Medical Research Council (NHMRC) Guidelines for Air Quality; • National Exposure Standards for Atmospheric Contaminants in the Occupational
Environment (NOHSC, 1003); • Air Quality Standards AS/NZS 3580.10.1:2003 - Methods for sampling and analysis of
ambient air; • Australian Standard AS2985-2004 workplace atmospheres-method for sampling and
gravimetric determination of respirable dust; • Australian Ventilation Standard AS 1666.2; and • Occupational Health and Safety Regulations and advisory standards. Relevant reports and documents include:
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• Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Soil Management Sub-plan, Hazardous Substance Management Sub-plan and Access and Public Safety Management Sub-plan are related to this Sub-plan.
10.4 Risk Assessment Table 12: Risk Assessment for Air Quality Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Nuisance dust impacting on nearby residences 5 3 15 HNuisance dust impacting on site workers 5 3 15 HImpact from nuisance dust on adjacent vegetated areas
3 2 6 L
Dust
Increasing turbidity and reducing the transfer of oxygen between air and water from dust settling on the local drainage channels
2 2 4 I
Greenhouse gases
Production of greenhouse gas emissions 5 1 5 I
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10.5 Management Actions – Air QualityEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Restrict movement on boundary firebreaks to thatrequired for AZRI property management
Regular road and trackmaintenance
High use roads should be constructed to minimisedust generation
Maintenance of access roads
A maximum speed limit of 20 km/h will be imposedwithin the site to control generation of dust byvehicles moving through operation areas
Meets the NHMRC Guidelinesfor Air Quality
Daily assessment of weather conditions Register of daily windconditions
During periods of high winds when soil moisture islow, additional precautions will need to beundertaken to protect exposed surfaces. Thesemay include increased frequency of watering andcessation of site operations during strong windswhich are likely to mobilise soils and dust,especially if winds are blowing towards sensitivereceiving areas (i.e. residential area)Ensure all exposed soils are stabilised e.g. usingmulch to assist with dust suppression
ContractorHorticulturalist
Mulching machine
Dust generating activitiesceased or suppressionmeasures implemented whenstrong winds present
Enhance the buffer zones that have poor vegetationcover
Horticulturalist Personnel to undertake works
Management ofnuisance dustemissions
Record any dust complaints ContractorHorticulturalist
Maintain a dust complaintsregister
No dust complaints
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaIf undertaking dust producing activities (sanding,grinding, welding) during construction of horticulturefacilities, engineering measures or PersonalProtective Equipment (PPE) must be used
Management ofoccupational dustemissions
Dust management on exposed soil surfaces,including onsite access tracks and stockpile sites,to be undertaken to reduce impact from airbornedust
Contractor PPE to be supplied to sitepersonnel
No dust complaintsMeets the National ExposureStandards for AtmosphericContaminants in theOccupational Environment(NOHSC, 1003)
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11 NOISE SUB-PLAN 11.1 Issues and Impacts During construction activities, noise levels above the background noise may be generated from plant and equipment used in excavation and construction. Construction activities that can cause noise include: • The installation of extraction and monitoring wells; • The clearing of land for infrastructure development; and • The building of infrastructure. The impact of noise on neighbouring residents will be largely dependent on the time of day noise is created and the direction of wind.
11.2 Objectives • To minimise noise emissions during construction activities; • To minimise noise emissions impacting on the adjacent residential area and other sensitive
receivers; and • To comply with relevant noise standards.
11.3 Applicable Legislation, Policies and References The following legislation applies to noise management: • Waste Management and Pollution Control Act 1998; and • Work Health Act 1986.
Relevant policies, codes of practice and measures include: • Draft Waste Management and Pollution Control (Environmental Noise) Regulations; • Australian Standard 2436-1981 Guide to Noise Control on Construction, Maintenance and
Demolition Sites; • Occupational Noise National Code of Practice; and • Occupational Health and Safety Regulations and advisory standards. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Access and Public Safety Management Sub-plan is related to this Sub-plan.
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11.4 Risk Assessment Table 13: Risk Assessment for Noise Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Noise from construction activities impacting on neighbouring residences resulting in noise complaints
5 3 15 HNoise
Impaired hearing of site personnel as the result of using noisy equipment
3 4 12 M
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11.5 Management Actions – NoiseEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Maintain minimum 50 m buffer distance fromresidential area and enhance buffer areas that havepoor vegetation cover
Enhancement of buffer zones
Where possible, avoid operating machinery andother vehicles near the residential area (westernside of site), between the hours of 1900 and 0700Machinery used at the site should be wellmaintained with high efficiency mufflers fitted to allsite equipment so that they conform to the NationalStandard for Occupational Noise (NOHSC: 1007(2000).Provide engineering measures to limit impact onworkforce using noisy equipment or providePersonal Protective Equipment whilst operating orworking near earthmoving equipment or othermachinery where required in accordance withnational standards
Maintenance of machineryPPE
Plant and EquipmentNoise
Record noise complaints
HorticulturalistContractor
Maintenance of a noisecomplaints register
No noise complaintsMeets Occupational NoiseNational Code of Practice
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12 ACCESS AND PUBLIC SAFETY SUB-PLAN 12.1 Issues and Impacts There is a risk that visitors (authorised and unauthorised) may access the construction site. This can potentially create liabilities for the construction and horticultural management. The impacts associated with construction activities include: • Insecure areas may result in members of the public harming themselves; • Insecure areas may result in operational equipment being damaged; and • Inappropriate site access points can create traffic problems and increase the risk of
accidents occurring and complaints being made.
12.2 Objectives • To minimise impacts of construction activities on existing roads and drainage systems; • To minimise the risk of injury to other road users and members of the public traversing
Colonel Rose Drive; • To minimise impacts on site visitors (authorised and unauthorised), local residents, tourists
and commuters; • To prevent unauthorised access of people; and • To prevent injury to site visitors.
12.3 Applicable Legislation, Policies and References The following legislation applies to access and public safety management: • Dangerous Goods Act 1981; and • Work Health Act 1986.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse
Scheme. The Noise Management Sub-plan and Air Quality Sub-plan are related to this Sub-plan.
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12.4 Risk Assessment Table 14: Risk Assessment for Access and Public Safety
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Vehicle accidents as the result of inappropriate site access points for entering and exiting site
3 3 9 L
Visitors (authorised and unauthorised) on site harming themselves
3 3 9 L
Site Access
Visitors (authorised and unauthorised) on site causing damage to operational equipment
3 3 9 L
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12.5 Management Actions – Access and Public SafetyEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Ensure site equipment is stored appropriatelyProvide fencing around site perimeter
Security measures, includingfencing
Develop a site OH&S Policy Personnel to develop policy
No injuries or accidents duringconstruction activities
Access management
Consult with Alice Springs Town Council re siting ofaccess point to horticultural site, particularly withrespect to traffic volume, visibility at entry point, andother traffic measures which may be required, suchas a turning lane
DBIRDContractor
Personnel to undertakeconsultation
No traffic incidences onColonel Rose Drive
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13 INDUCTION TRAINING REQUIREMENTS The purpose of induction training is to ensure that all personnel who are engaged in the construction at the horticulture site are aware of their environmental obligations. The horticultural manager is responsible for the conduct of environmental induction training for all persons working on site, including any subcontractors. An experienced and qualified environmental trainer is to undertake environmental induction training for all personnel involved in the construction of the horticultural site. It is proposed that the environmental induction training for site personnel and sub-contractors can be undertaken at two levels: 1. Complete induction - training for personnel who will be on-site for more than five days or
those personnel on-site for less than five days but involved in activities that have the potential to cause environmental harm (e.g. installation and maintenance of erosion and sediment control devices, clearing and grubbing, felling of trees, earthworks, stabilising disturbed surfaces); and
2. Quick induction - training for personnel that will be on-site for less than five days and are undertaking activities that do not have the potential to cause significant environmental harm.
An induction training programme for both induction levels needs to be developed. The induction training for both levels should cover the same issues. The difference between the two induction courses is the level of training provided for each issue. The issues to be addressed in induction include (but are not limited) to the following: • Awareness of the Horticulture CEMP; • Awareness of general environmental duties under the relevant Acts and the consequences
of any breaches; • An overview of what constitutes an environmental incident and the appropriate person to
notify in the event of an environmental incident; • General awareness of the environmental and cultural significance of the adjacent local
drainage channels, vegetation corridors and buffer area; • Location of No Go areas, particularly St Mary’s Creek, the buffer area and recognised
cultural areas; • Specific practices required for erosion and sediment control; • Specific practices required for clearing and grubbing; • General flora and fauna management; • Appropriate locations for the parking of vehicles and machinery/plant equipment; • The need for off-site maintenance and wash down (if required) of construction vehicles; • Speed limit restrictions throughout the site; • Procedures to follow and who to contact in the case of a hydrocarbon or other hazardous
substance spill; • The location and use of fire extinguishers/hydrants; • Appropriate waste management practices; and • The appropriate person to notify in the event that any environmental mishaps occur. The environmental induction training can be undertaken alongside the OH&S training.
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14 MONITORING FRAMEWORK Monitoring is the systematic collection of data and information in relation to specific environmental issues or conditions. The main purposes of monitoring are: • To identify trends and changes over time and between areas to enable identification of
measures to improve environmental practices and performance; and • To assist in the identification of non-predicted impacts. There are two main areas that can be monitored, environmental condition and environmental management.
14.1 Environmental Condition Monitoring of environmental condition will establish whether the recommended practices in this EMP are effective in achieving their desired environmental outcome and will allow for the detection of non-predicted impacts. The principle issues requiring monitoring during the construction phase for the horticulture scheme relate to: • Changes to groundwater properties:
o Construction works have the potential to impact on the groundwater height and chemistry;
o Potential to cause contamination of groundwater as the result of accidental spills and or leakage of toxic or hazardous substances; and
o Compaction and excavation activities which are likely to occur during construction may cause the diversion of groundwater flow;
• Changes to surface water quality and quantity; • Change to vegetation structure and fauna habitats; • Complaints received from neighbouring properties from nuisance dust and excessive noise
caused by construction activities; and • Increase in the number of mosquitoes/biting insects.
14.1.1 Groundwater Monitoring Although the monitoring strategy outlined below focuses on water quality changes during operational phases, it should be commenced during construction and then continued through the operational phases. This will provide baseline data on groundwater condition prior to the commencement of SAT construction and operation and horticultural construction and operation. Monitoring of the groundwater will be from four distinct levels within the subsurface: • Alluvial Layer 2: Within the more porous and permeable layer of sands and gravel to
typical depths of 3 m to 5 m; • Alluvial Layer 4: Within the more porous and permeable layer of silty sand and gravel
located above the main low permeability clay cap overlying the palaeochannel to typical depths of 9 m to 11 m;
• Alluvial Layer 6: Within both the main palaeochannel to depths of approximately 30 m and the more widespread layer outside the palaeochannel to depths of approximately 20 m; and
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• Tertiary Aquifers: Within the upper thin layers of sand material located at depths of approximately 50 m and greater below the overlying sequence of low permeability clays.
Monitoring these levels of groundwater will demonstrate that the objectives of enhanced water treatment, environmental protection and opportunities for reuse are achieved and will support the ongoing effective and efficient management of the horticulture venture. The monitoring bore network will be located in the following areas: • Immediately below the SAT infiltration basins (nominally four sets of bores); • Immediately adjacent to the SAT infiltration basins (nominally six sets of bores); • Adjacent to the aerial extent of the palaeochannel feature within the AZRI site around the
infiltration basins (nominally six sets of bores); and • Adjacent to the boundary of the AZRI site with the rural residential properties, Colonel
Rose Drive and Todd River and an equivalent distance to the west of the infiltration basins within the AZRI site (nominally eight sets of bores).
The migration of relatively saline groundwater down existing extraction bore annuli will also require monitoring and the most appropriate monitoring locations for this will be using the existing monitoring bores where access is available. The monitoring programme will include each of the existing Tertiary extraction wells located within the AZRI site and a representative selection of six extraction wells within the adjacent rural residential properties. A sampling and analysis programme will be established prior to the commencement of infiltration of recycled water in the SAT basins or use of recycled water in irrigation to measure ambient groundwater concentrations. The sampling and analysis programme will be undertaken for a suite of contaminants including major ions, metals and nutrients (Table 15). Table 15: Groundwater Monitoring during Commissioning Parameter Suggested Determinants Frequency of
testing per year Site(s)
Heavy Metals Al, As, B, Cu, Cd, Cr, Zn (as minimum suite)
4 Monitoring bores
Dominant ions Ca, Na, K, Cl, SO4, HCO3. 4 Infiltration ponds and monitoring bores
TDS Conductance (25°C). Calculation based on above.
12 Infiltration ponds and monitoring bores
Organics Pesticides, MBAS, TOC and DOC
2 Infiltration ponds and monitoring bores
Field determinations pH, turbidity, temperature, dissolved oxygen, ORP
52 Infiltration ponds and monitoring bores
Oxygen demand BOD, COD 12 Infiltration ponds and monitoring bores
Bacteriological indicators
Coliforms and E. coli 12 Infiltration ponds and monitoring bores
Pathogen indicators C. perfringens, viruses 4 Infiltration ponds and monitoring bores
Nutrients Total and dissolved P, Total N, TKN, NOx
4 Infiltration ponds and monitoring bores
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Use of sophisticated analysis systems such as polymerase chain reaction should be used to monitor for viruses of human concern, particularly coliphage variants.
14.1.2 Monitoring Soil Erosion During a rainfall event the risk for soil erosion to occur on site increases. Therefore it will be a requirement of the EMP to undertake regular monitoring of the surface water runoff from the site to determine if erosion control measures are required. If it is found that significant levels of sediments are flowing into St Mary’s Creek or other drainage channels, sediment control measures, i.e. silt fencing and temporary sediment retention basins, should be installed.
14.1.3 Dust, Noise and Odour Complaints Monitoring Dust, noise and odours are not expected to adversely impact on neighbouring properties as long as construction activities are carried out within the relevant safeguards identified in this EMP. A complaints register should be established and complaints investigated. The complaints register should report the following information: • Date and time of complaint; • Date and time of incident; • Location; • Weather data to determine wind speed and direction to assist in identifying source of
nuisance; • Type of complaint – noise, dust or odour; • Description of complaint; • Contact details of complainant; • Who recorded complaint; • Who was responsible for investigating the complaint; and • Results or outcomes of investigation and follow up. If safeguards and control measures for noise, dust or odours fail and complaints have been received, monitoring of these aspects should be undertaken. The monitoring activities for dust, noise and odour are described below: • Dust monitoring will be undertaken following the Air Quality Standards AS 3580.10.1:2003 -
Methods for sampling and analysis of ambient air. The siting of the air sampling units will require one in the location of the complainant and a background unit located upwind of the horticultural site;
• Environmental noise monitoring will be undertaken in accordance with the AS 1055.1:1997 Acoustics—Description and measurement of environmental noise, which sets out general procedures for the description and measurement of environmental noise including repetitive impulsive noise and AS 1055.2:1989 Application to specific situations; and
• Monitoring odour is slightly more difficult, as odour recognition is a sensation resulting from the reception of a stimulus by the olfactory sensory system. The human response to an odour is only able to be evaluated depending on the particular sensory property that is being measured, including the intensity, detectability, character, and hedonic tone of the odour. The combined effect of these properties is related to the annoyance that may be caused by the odour. Therefore if a number of complaints are received (approximately
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10% of the affected population) measures should be undertaken to identify the source of the odour and investigate ways to mitigate and manage.
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14.1.4 Vegetation, Habitat and Fauna Monitoring Prior to clearing activities it is recommended that a targeted survey of the area be undertaken to ascertain the presence or absence of Threatened species. In the event that such species are located, further consideration of their management will be required. For example, if it is a Threatened fauna species, options for relocation (and subsequent survival after relocation) would need to be investigated. If it is a Threatened flora species, options for seed collection and propagation should be investigated (relatively few native flora species survive translocation). Monitoring of weeds and pest species on site should be undertaken on a regular basis (quarterly) to ensure that construction activities are not exacerbating the current weed problems or increasing the number of feral species present. Weed control should be undertaken as part of an annual weed control programme.
14.1.5 Mosquito/Biting Insect Monitoring During the construction phase of the horticultural venture, it is unlikely that mosquito populations will increase as the construction phase does not involve creation of water-bodies in which mosquito breeding can occur. For this phase, monitoring should focus on prevention of ponding areas, particularly if vegetation is also present, to prevent the creation of breeding habitat.
14.2 Environmental Management In addition to monitoring environmental conditions, it is also important to monitor the development and implementation of the environmental management processes within the construction activities of the horticulture venture. Environmental management is the process by which the construction manager can ensure compliance to environmental legislation and minimise environmental risks. Environmental management monitoring for the construction activities will include: • Periodic reviews and auditing of construction to ensure recommended activities are being
carried out; and • Periodic reviews and audits of construction activities to ensure the management action
tables provided in this EMP are being used as a checklist for ensuring all environmental management measures are being implemented.
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15 AUDITING Environmental auditing is an integral part of the environmental management of the construction activities for the horticulture venture. It is an important management tool that is a systematic, documented, periodic and objective evaluation of the environmental management practises on site. The audit assists in verifying how well the operation is performing against the CEMP and processes, to determine the level of compliance with the nominated environmental criteria. Environmental auditing should be seen as an opportunity for the continual improvement of management practises at the site. It should also be conducted during any or all stages of the proposed activities and can be undertaken in conjunction with other system audits, such as workplace health and safety, quality and contract administration, or it can be undertaken as a separate environmental audit.
15.1 Periodic Review Periodic reviews during construction of the horticulture venture will be required to ensure the measures set in the CEMP are being implemented. The periodic review will be undertaken by the relevant responsible bodies as described in the management sub-plans. The periodic review of construction activities will be undertaken in the form of an informal inspection. The objectives of the review are to identify: • Physical aspects of the construction activities which are not in compliance with the set
requirements of this CEMP; and • Any aspects of the construction activities that may have caused or have the potential to
cause environmental harm, including impacts that have not been predicted or addressed. While these inspections will be less rigorous than actual environmental audits, they play an important role in identifying non-conformances that may require immediate remedial action. These inspections can also be important mechanism for identifying areas that may need to be audited in the future. The informal inspections should be undertaken throughout the life of the construction activities at least once per week (depending on the activities taking place on site); particularly during key developmental stages or activities, such as: • Prior to commencement of works; • During and at the completion of building construction; • On the arrival of top soil; • During heavy rainfall events to monitor runoff from site; and • During clearing of vegetation.
15.2 Environmental Audit It is recommended that environmental audits will be undertaken within the first couple of weeks of construction activities and at the completion of construction. Compliance audit will be the primary audit undertaken during construction which is similar to the periodic review only it is more thorough and the audit will be conducted by someone external to the process. The audit can be undertaken by relevant, trained members of an organisation’s own staff (i.e. Environmental Officer) or by external, professional auditor.
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15.3 Non-conformance Procedures Non-conformance procedures are those procedures that should be followed in the event that a site audit or inspection identifies a breach of the agreed environmental management strategies has occurred. These procedures apply to all personnel including any sub-contractors. In the event of a non-conformance, the following procedures should be followed: • The non-conformance activity should cease; • The Construction Manager should be contacted, who will then contact the Environment
Manager, Safety Officer or other personnel as required; • Assess the degree of non-conformance and extent of resultant environmental impact (if
any); • Determine procedures for mitigation or management; and • Undertake management or mitigation procedures to the satisfaction of the Environment
Officer. Each non-conformance should be documented, along with the corrective actions undertaken.
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Appendix 9: Operation Environmental Management Plan Soil Aquifer Treatment Scheme
Soil Aquifer Treatment Operation Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005 Prepared for: Power and Water Corporation PO Box 1521 ALICE SPRINGS NT 0871
Report by: HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia Ph: +61 8 8935 0515 Fax: +61 8 8932 5369 HLA Ref: B600270_RPT_Final_SATOEMP_11Apr05.doc
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DISTRIBUTION Soil Aquifer Treatment Operation Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005
Copies Recipient Copies Recipient 1 Mark Skinner
Senior Project Manager PO Box 1521 ALICE SPRINGS NT 0871
This document was prepared for the sole use of Power and Water Corporation and the regulatory agencies that are directly involved in this project, the only intended beneficiaries of our work. No other party should rely on the information contained herein without the prior written consent of HLA-Envirosciences Pty Limited and Power and Water Corporation.
By HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia
____________________________________ Alana Eggleton Environmental Scientist
Peer Review: Date:
11 April 2005
Dr Sandy Griffin Principal Environmental Scientist
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CONTENTS
1 THE SAT OPERATION EMP......................................................................................... 1 1.1 Introduction ..................................................................................................... 1 1.2 Background..................................................................................................... 1 1.3 Purpose........................................................................................................... 1 1.4 Risk Assessment ............................................................................................ 2 1.5 Management Strategies.................................................................................. 3
2 SOIL MANAGEMENT SUB-PLAN................................................................................ 4 2.1 Issues and Impacts......................................................................................... 4 2.2 Objectives ....................................................................................................... 4 2.3 Applicable Legislation, Policies and References ............................................ 4 2.4 Risk Assessment ............................................................................................ 5 2.5 Management Actions – Soil and Erosion........................................................ 6
3 WATER MANAGEMENT SUB-PLAN ........................................................................... 9 3.1 Issues and Impacts......................................................................................... 9 3.2 Objectives ..................................................................................................... 10 3.3 Applicable Legislation, Policies and References .......................................... 10 3.4 Risk Assessment .......................................................................................... 11 3.5 Management Actions – Water ...................................................................... 12
4 WASTE MANAGEMENT SUB-PLAN ......................................................................... 14 4.1 Issues and Impacts....................................................................................... 14 4.2 Objective ....................................................................................................... 14 4.3 Applicable Legislation, Policies and References .......................................... 14 4.4 Risk Assessment .......................................................................................... 15 4.5 Management Actions - Waste....................................................................... 16
5 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN ...................... 17 5.1 Issues and Impacts....................................................................................... 17 5.2 Objectives ..................................................................................................... 17 5.3 Applicable Legislation, Policies and References .......................................... 17 5.4 Risk Assessment .......................................................................................... 18 5.5 Management Actions - Vegetation, Fauna and Habitat................................ 19
6 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN ..................................... 20 6.1 Issues and Impacts....................................................................................... 20 6.2 Objectives ..................................................................................................... 20 6.3 Applicable Legislation, Policies and References .......................................... 20 6.4 Risk Assessment .......................................................................................... 21 6.5 Management Actions – Weeds and Pest Species........................................ 22
7 FIRE MANAGEMENT SUB-PLAN .............................................................................. 23
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7.1 Issues and Impacts....................................................................................... 23 7.2 Objectives ..................................................................................................... 23 7.3 Applicable Legislation, Policies and References .......................................... 23 7.4 Risk Assessment .......................................................................................... 24 7.5 Management Actions – Fire.......................................................................... 25
8 AIR QUALITY MANAGEMENT SUB-PLAN ............................................................... 26 8.1 Issues and Impacts....................................................................................... 26 8.2 Objectives ..................................................................................................... 26 8.3 Applicable Legislation, Policies and References .......................................... 26 8.4 Risk Assessment .......................................................................................... 27 8.5 Management Actions – Air Quality ............................................................... 28
9 ACCESS AND PUBLIC SAFETY MANAGEMENT SUB-PLAN................................. 30 9.1 Issues and Impacts....................................................................................... 30 9.2 Objectives ..................................................................................................... 30 9.3 Applicable Legislation, Policies and References .......................................... 30 9.4 Risk Assessment .......................................................................................... 30 9.5 Management Actions – Access and Public Safety ....................................... 31
10 INDUCTION TRAINING REQUIREMENTS................................................................. 32 11 MONITORING FRAMEWORK..................................................................................... 33
11.1 Environmental Condition............................................................................... 33 11.1.1 Groundwater Monitoring................................................................ 33 11.1.2 Soil Testing.................................................................................... 35 11.1.3 Monitoring of Recycled Water Entering SAT Basin....................... 36 11.1.4 Dust, Noise and Odour Complaints monitoring............................. 36 11.1.5 Mosquito / Biting Insect Monitoring ............................................... 37
11.2 Environmental Management......................................................................... 38 12 AUDITING.................................................................................................................... 39
12.1 Periodic Review ............................................................................................ 39 12.2 Environmental Audit...................................................................................... 39 12.3 Non-conformance Procedures...................................................................... 40
TABLES
Table 1: Measure of Likelihood ....................................................................................................2 Table 2: Measure of Consequence ..............................................................................................3 Table 3: Risk Assessment Scoring...............................................................................................3 Table 4: Risk Assessment for Soil and Erosion Issues................................................................5 Table 5: Risk Assessment for Water Management Issues ........................................................11 Table 6: Risk Assessment for Waste Issues ..............................................................................15 Table 8: Risk Assessment of Vegetation, Fauna and Habitat Issues .........................................18 Table 9: Risk Assessment for Weeds and Pest Species ...........................................................21 Table 10: Risk Assessment for Fire Issues .................................................................................24 Table 12: Risk Assessment for Air Quality Issues......................................................................27
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Table 14: Risk Assessment for Access and Public Safety.........................................................30 Table 15: Groundwater Monitoring during SAT Operation.........................................................35 Table 16: Soil Testing on the SAT Basins for First Year of Operation .......................................36
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1 THE SAT OPERATION EMP 1.1 Introduction This Operation Environmental Management Plan (OEMP) has been prepared for the operational phase of the Soil Aquifer Treatment plant at the Arid Zone Research Institute (AZRI), located approximately 10 km south of Alice Springs, Northern Territory. The Public Environment Report (PER) Guidelines issued by the Office of Environment and Heritage (OEH) required the submission of four EMPs to accompany the PER. This OEMP has been developed in accordance with the guidelines of the PER. A detailed description of the proposed Alice Springs Water Reuse Scheme is provided in the Public Environment Report, which accompanies this OEMP. The OEMP outlines measures to manage the environmental integrity of the site during operational activities. The principal objective of the OEMP is to provide effective and practical management strategies that will avoid, ameliorate or mitigate potential adverse impacts associated with the proposed operational phase of the SAT facilities and the associated infrastructure. The OEMP includes clear instructions for management, monitoring and performance evaluation and is guided by the relevant legislation and other codes of practice.
1.2 Background The Alice Springs Water Reuse Scheme proposes to utilise SAT technology to polish and store recycled water in groundwater aquifers, for later extraction and use for horticultural irrigation. The recycled water originates from the Alice Springs Waste Stabilisation Ponds (WSP), from which wastewater is treated by Dissolved Air Flotation and chlorination, to produce recycled water. The scheme is expected to produce up to 6 ML of recycled water per day for reuse. The water quality will be suitable for reuse in accordance with national water quality guidelines and will be subject to regulation under the Water Act and Public Health Act.
The SAT operations will primarily involve: • Infiltration of recycled water through two kidney shaped basins, each subdivided into four
sub-basins. Wastewater from the Alice Springs WSP is treated by Dissolved Air Flotation plant and chlorination, prior to transfer of the recycled water product to the SAT basins;
• Recharge of approximately 600 ML/year to 1,200 ML/year of recycled water to the underlying shallow aquifer;
• Management of recycled water input, infiltration rates and the infiltration mound; and • Management of associated infrastructure, such as pumps, pipelines and automatic delivery
systems.
1.3 Purpose The OEMP aims to: • Provide details of proposed measures to prevent or minimise adverse impacts and assess
the likely effectiveness of these safeguards; • Ensure that safeguards are being effectively applied; • Enable remedial action for any impacts that were not anticipated in the PER;
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• Determine the differences between predicted and actual impacts (via monitoring); and • Provide for the periodic review of the management plan itself. The OEMP provides an ongoing interactive process for defining, documenting and improving the environmental management of the SAT operations. The OEMP is intended to be a ‘living’ document which allows for it to be continuously updated reflecting feedback from the reporting conducted under the plan and recommendations arising from monitoring and audits. This OEMP is accompanied by a Construction EMP (CEMP) for construction of the SAT facilities. The CEMP addresses the management of environmental impacts associated with construction activities. Aspects not considered significant for the operation of the SAT scheme include: • Use of hazardous substances – the SAT scheme does not involve the use of hazardous
substances. Weeds should be controlled physically or mechanically rather than chemically and any pre-treatment of recycled water occurs at the Alice Springs Waste Water Treatment Plant, prior to reaching the SAT basin site;
• Disturbance of heritage items – the proposed site for the SAT basins does not contain any trees identified as being culturally significant and no artefacts were located during an archaeological survey of the site in 2004; and
• Noise – sources of noise associated with the operation of the SAT scheme will include pumps and occasional heavy machinery for basin floor maintenance. These activities are not expected to create undue noise and are not expected to be detected by sensitive receiving environments such as neighbouring residents because of the distance from the SAT basins to these areas. The noise created through such activities does not represent a change from current noise levels at AZRI.
These aspects have been discussed in detail in the SAT CEMP and the Horticulture CEMP and OEMP.
1.4 Risk Assessment A risk assessment, based on AS4360:1999 Risk Management, was undertaken on the potential environmental incidences that may arise during operation of the SAT scheme. The risk assessment combines (qualitative) estimates of the likelihood of a certain event or environmental impact occurring (Table 1) and the consequence (Table 2). Table 1: Measure of Likelihood Level Descriptor Description
1 Rare Environmental impact may occur only in exceptional circumstances 2 Unlikely Environmental impact could occur at some time based on current
practices 3 Moderate Environmental impact has a moderate probability of occurring based
on current practices 4 Likely Environmental impact will probably occur based on current practices 5 Almost Certain Environmental impact is expected to occur in most circumstances or
is already occurring
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Table 2: Measure of Consequence Level Descriptor Description
1 Insignificant Negligible short term environmental impact to habitat with no monitoring required
2 Minor Some short term environmental disturbance with localised impacts, some management required
3 Moderate Obvious environmental impact to habitat, more widespread effects, normal incident management response is sufficient
4 Major Substantial environmental harm, loss of immediate habitat, widespread side effects over extended time, long term remediation management required, external agencies utilised
5 Catastrophic High degree of environmental harm, permanent loss of widespread habitat, loss of species, external agencies utilised, incident of regional significance
The likelihood of an event occurring is multiplied by the environmental consequence in order to determine the significance of the impact and, hence, its priority for management (Table 3). Table 3: Risk Assessment Scoring
Score Management required 25 Extreme risk: immediate action required to intervene and prevent incident.
15 – 20 High risk: prompt senior management attention of potential environmental impact. 10 – 14 Moderate risk: high priority issue requiring regular management and monitoring. 6 – 9 Low risk: low priority issue that can be managed by routine procedures 1 – 5 Insignificant risk: issue of low importance not requiring management but only
occasional monitoring.
The results of the risk assessment have been provided in each aspects sub-plan.
1.5 Management Strategies The following sections provide a description of each aspect or activity that has the potential to impact on the environment and strategies for the management of these potential impacts. Reference has been made to the appropriate section of the PER, where appropriate.
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2 SOIL MANAGEMENT SUB-PLAN 2.1 Issues and Impacts Soil management during the SAT system operation will primarily involve management of the accumulation of organic and other suspended solids on the basin floor which can result in a decline of infiltration rates over the wetting cycle. The soil and erosion issues for SAT operational activities include: • Clogging beneath the surficial layer of the SAT Basins, which may affect infiltration rates:
o Over a large number of wet/dry cycles a decline in the infiltration rate below the SAT system design target can occur as the result of an accumulation of fine materials on the basin floor;
• Soil contamination during: o SAT basin infiltration operation - infiltration trials and preliminary groundwater
modelling results indicate that there is a very low probability of surface discharge or water logging issues arising from the SAT operation; and
o Site vehicle and equipment refuelling and maintenance – pollution of soils from hazardous and toxic substances as a result of fuel spills, chemical spills or wash down activities;
• Water Erosion – potential for disturbed soils and fill to be transported by surface flow during rainfall events and/or on site water usage. This can cause: o Loss of soil during site operations and may result in the formation of gullies and rills
along bare soil surfaces and slopes, such as the sides of the infiltration basins; • Wind Erosion - potential for windblown sediments (dust) to be transported off-site;
o Loss of soil from site during vehicle movement and site operation works; and o Dust settling on local drainage channels, increasing turbidity and reducing transfer of
oxygen from air to water; and • Compaction - heavy vehicles moving within the infiltration basins during maintenance
activities may cause compaction. Compaction of soil may affect infiltration rates.
2.2 Objectives • To manage effectively clogging of the surficial layer of the SAT basin floors; • To minimise soil erosion and compaction around SAT facility and infrastructure; • To minimise dust impacts from general operations; and • To prevent degradation of soils during operation of the SAT facility.
2.3 Applicable Legislation, Policies and References The following legislation applies to soil and erosion management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Soil Conservation and Land Utilization Act 1980;
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• Water Act 1992; and • Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures includes: • National Environmental Protection (Assessment of Site Contamination) Measure 1999. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 59 to 77; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Vegetation, Fauna and Habitat Management Sub-plan, Weed and Pest Species Management Sub-plan, Air Quality Sub-plan and the Access and Public Safety Sub-plan are related to this Sub-plan.
2.4 Risk Assessment Table 4: Risk Assessment for Soil and Erosion Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
ConsequencTotal
Priority
Clogging of soils Reduced infiltration rates within the SAT basins, potentially leading to overflow of recycled water into the overflow sub-basin
4 3 12 M
Discharge or water logging issues arising from the SAT operation
3 2 6 L
Change to nutrient status of soils in SAT basins 3 4 12 M
Chemical changes to soil / pollution of soil
Contamination of soils from fuel and chemical handling, storage and spills
3 2 6 L
Erosion of soil The formation of gullies and rills along bare soil surfaces and slopes, such as on the basin walls
3 4 12 M
Generation of dust by vehicle movement and general operations (i.e. site maintenance)
3 4 12 MCreation of Dust
Increasing turbidity and reducing transfer of oxygen from air to water as the result of dust settling on local drainage channels
3 3 9 L
Compaction of Soils
Compaction of soils from heavy vehicle movement within basins during maintenance of basin floor, thereby affecting infiltration rates
4 2 8 L
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2.5 Management Actions – Soil and ErosionEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Stabilise walls of infiltration basin to preventmovement of fines into the basins (exacerbatingclogging)
Provide erosion controlmatting or rock reinforcementto basin walls
Prevent erosion of the basin floor by placing anenergy dissipater at the point of inflow. May includea rock or concrete apron type structure
Engineer inflow to dissipateflow into basin
No erosion of basin walls orfloor
Use a 7 day wet/dry cycle and adjust as required tomaximise infiltration and soil aeration
Weekly inspection ofinfiltration basins
Alternate sub-basin use between the three pairs ofsub-basinsAnnual (or more/less frequent as required)maintenance to scarify basin floor and removesediment and organic material build-up by discploughing or scraping
Maintenance programme
In-line monitoring of waste water quality
Soil management
Undertake in-line monitoring of water levels inponds and recycled water inflow rates to maintainwater levels
Power & Water
Routine monitoring
Infiltration rates aremaintained at appropriate rateto deliver quantity of recycledwater required for horticulture
Water erosionprevention strategy
During rainfall events, monitor the surface waterrun-off to determine whether erosion controlmeasures are being effective. If it is found thatsignificant levels of sediments are flowing off-site,i.e. silt fencing and temporary sediment retentionbasins, should be installed
Power & Water Undertake monitoring of run-off from SAT site for anysignificant increase insediment movement
No significant movement ofsediments off-site
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaEnsure basin walls are stabilised with waste rock,matting or other suitable inert materials
Undertake weekly inspectionof basin walls to ensurestabilised
Ensure erosion control measures are working Inspection of erosion controlmeasures during rainfallevents or high use of water onsite
Water erosionprevention strategycontinued
Augment soils with gypsum to minimise dispersiontendency
Power & Water
Soil augmentation
No significant movement ofsediments off-site
Vehicles must travel at <20 km/hr over unsealedroads to keep dust levels downMinimise vehicle access on site to what isnecessaryFirebreaks should be strictly used only by AZRI forproperty management rather than for SAT purposes
Training of site personnelSpeed limit signage
Minimise exposed soil surfaces on SAT site throughimplementation of groundcover planting strategy
Personnel to undertakingplanting
Wind erosion preventionstrategy
Establish dust complaints register
Power & Water
Maintenance of register
Dust levels within relevantenvironmental dust criteria(NEPM)No dust complaints
Provide procedures to manage fuel and otherchemical spills including use of fuel spill kitsProvide appropriate containment and control
Soil contaminationmitigation
Maintain register of hazardous substances andcoming onto site
Power & Water Bunded areas / containmentor control structuresTraining of site personnel torespond to hazardoussubstance incidencesDispose hazardous chemicalsand fuels to an authorisedlandfill
No staining on surface soilaround fuel and otherchemical storage areas
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaAnnual maintenance of scarify basin floor to removesediment and organic material build up
Disc plough or scrapingequipment
Soil nutrient statusmanagement
Alternate sub-basin use
Power & Water
Undertake soil testing
No long term change in soilnutrient status
Prevent movement on or working of soils whilst wetFit earthmoving/maintenance equipment with lowfloatation tyresLimit the number of vehicles and earthmovingequipment travelling across site to what isnecessary
Compactionmanagement
Remediate any areas which have been impacted byrip/furrow/aeration of the impacted soils
Power & Water Training of site personnelLandscaping/maintenanceequipment
Monitoring shows no netdecrease in infiltration rates
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3 WATER MANAGEMENT SUB-PLAN 3.1 Issues and Impacts Water management during the SAT system operation will primarily involve management of the recycled water infiltrate and management of groundwater quality. Indications from modelling based on the current level of knowledge of the ’native‘ groundwater shows that the current rate of ’native‘ groundwater movement through the system is of similar nature to that proposed to be applied through SAT scheme. The ’native‘ groundwater has a higher salinity than the infiltrate and appears to be derived from several sources, including the Town Basin outflow, Todd River flood outs, effluent irrigation at Blatherskite Park, Ilparpa Swamp flows and locally occurring run-off recharge. As a result of these multiple sources, and the high rates of aquifer through-flow, the native groundwater quality is variable over time, yet it is generally too saline to support potable use. The SAT operation is unlikely to produce discernible changes to the existing groundwater quality regime other than in relatively close proximity to the SAT site itself, where water quality enhancement is expected to take place. The enhancement, especially reduction in water salinity, is expected to be sufficient to enable the recycled water to be used for irrigation purposes. Activities that have the potential to impact on the natural hydrogeology and groundwater quality include: • Infiltration of recycled water – potential to alter aquifer properties and groundwater quality.
Changes to the groundwater height and chemistry may occur during infiltration, such as mobilisation of additional stored salts within the soil profile;
• Recovery of treated water for irrigation will has the potential to alter groundwater levels and aquifer properties;
• Recycled water volumes in excess of infiltration capacity; and • Potential to contaminate ground water because of seepage of toxic or hazardous
substances from accidental spills and/or leakage on site. Those activities that have the potential to impact upon stormwater and surface water quality are: • Site vehicle and equipment refuelling and maintenance – pollution of surface waters from
hazardous and toxic substances draining into local drainage channels as a result of fuel spills, chemical spills or wash down activities;
• Chemical storage and usage e.g. herbicides and pesticides – pollution of surface waters or stormwater from hazardous and toxic substances as a result of chemical spills or application activities;
• Maintenance of pipeline to basins and other site infrastructure – minor earthworks may encourage soil erosion; and
• Monitoring and maintenance of monitoring bores – disturbance of soils for access and maintenance may encourage soil erosion.
There is also potential for flood events greater than a 1 in 50 year event to occur, which may cause the SAT basins to be inundated. It is expected that during these times the flow of recycled water into the basins will be stopped. The water in the infiltration basins will infiltrate relatively quickly (<1 day) preventing recycled water mixing with the flood water. The flood water will also recharge the shallow aquifer system and it is likely that the flood water will improve the quality of the water already in storage, since the salinity of the river water
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(~100 mg/L) is much lower than the recycled water (~1,000 mg/L). In general, the interruption to the SAT operation as a function of locally significant flooding of this scale is not expected to be for more than a few weeks to a month at a time.
3.2 Objectives • To ensure there are no adverse impacts upon groundwater resulting from SAT operation; • To ensure there are no adverse impacts upon surface water or stormwater, as a result of
operations; and • To comply with legislative standards.
3.3 Applicable Legislation, Policies and References The following legislation applies to water management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Water Act 1992; and • Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures include: • National Environmental Protection (Assessment of Site Contamination) Measure 1999; and • Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 78 to 119; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Waste Management Sub-plan and Hazardous Products Management Sub-plan are related to this Sub-plan.
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3.4 Risk Assessment Table 5: Risk Assessment for Water Management Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Inadequate infiltration of recycled water of SAT basins has the potential to alter aquifer properties and groundwater quality.
2 3 6 L
Localised surface seepage or ponding outside of SAT basin
3 3 9 L
Widespread surface seepage or ponding outside SAT Basin
3 4 12 M
Increase in long term, widespread groundwater levels standing within <10m of the surface
3 5 15 H
Potential to contaminate ground water due to the seepage of toxic or hazardous substances from accidental spills and/or leakage on site
2 4 8 L
Significant lateral movement of groundwater outside paleochannel
3 5 15 H
Groundwater movement to other aquifer systems 3 4 12 MPreferential flow of lower quality groundwater from quaternary systems to underlying Tertiary Systems along existing bore networks
3 4 12 M
Contamination and Alteration of Groundwater
Waste water volumes in excess of infiltration capacity
2 4 6 L
Surface water contamination due to soil erosion run-off
3 2 6 L
Surface water contamination due to chemical use 3 2 6 L
Contamination of Surface water
Contamination of surface water through fuel or chemical spills
3 2 6 L
Flood event Flood event, greater than a 1 in 50 year event, resulting in SAT basins to be inundated
2 3 6 L
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3.5 Management Actions – WaterEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Establish a groundwater monitoring programme ofextraction boresRegularly undertake groundwater monitoring of theupper layers of the aquifer immediately adjacent tothe basinsGroundwater sampling should occur at one or morelocations within close proximity of the basins(<20 m), intermediate to the basins and theextraction bores and at the extraction boresWater levels and water samples should be collectedregionally to assess the dimensions of the infiltratedplumeInstall localised drainage bores to intercept nearsurface lateral flowsInstall localised low permeability barriers to blocknear-surface preferential flow pathwaysMonitor the recycled water entering basins forpathogenic content and other potentialcontaminants
Groundwatercontamination andalteration mitigation
Ensure recycled water is allowed sufficient aquiferresidence time to meet recycled water qualitystandards requirements
Power & Water Installation of extensivegroundwater network targetingthe paleochannel and themore shallow permeablelayers radiating outward fromthe SAT basins to the AZRIsite boundariesRoutine monitoring of waterfrom extraction boresResources to record andmanage analytical results
Comply with relevant waterquality standardsNo adverse impact ongroundwater qualityNo significant change ingroundwater height
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaDuring rainfall events, undertake regularinspections of Sat basin walls to ensure sedimentsnot moving off-site into local drainage linesIf required, establish erosion control measures, i.e.silt traps, retention basins, within identified run-offareas
Regular inspections ofdrainage areasInstallation of erosion controlmeasures
No change in existing run-offpattern
Contain all hazardous substances, fuels andchemicals, in appropriate areas (i.e. bunding,containment areas and control structures)
Maintenance of bunded areas,containment or controlstructures
Surfacewater/Stormwatercontamination mitigation
Engineer stormwater drains to reduce the velocityof stormwater and enable removal of contaminantsprior to entering sensitive receiving waters
Power & Water
Dispose of waste chemicals toan authorised landfill whererequired
No incidences of fuel leaks orspills
Recycled watermanagement practices
If recycled water is in excess of infiltration capacitydivert recycled water to existing evaporation pondsat Alice Springs Waste Water Treatment Plantand/or use at Blatherskite Park and Tree Lot, butwith improved irrigation efficiency and design
Power & Water In-line monitoring of waterinflow rates and basin volume
No occurrences of overflow ofbasins
Early warning alert in place to provide time to shutdown recycled water transferFlow of recycled water into the basins will stop
Flood management
Maintain regular maintenance activities of SATbasins to ensure infiltration rates are able to copewith flood event
Power & Water Weather dataAutomatic monitoring of waterlevels in pondsBasin design
No occurrences of overflow ofbasins
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4 WASTE MANAGEMENT SUB-PLAN 4.1 Issues and Impacts The wastes that may be generated during SAT operations will primarily be organic wastes. Filtrate mats, which are a waste by-product from the infiltration of recycled water, are likely to form on the SAT basin floor. The filtrate mat is made up of organic matter and algal particulates. The potential impacts associated with organic waste materials are: • The filtrate mats may contain heavy metals or toxic organic residues and potential
pathogens (e.g. Cyclospora); • Potential to attract pest species to site as the result of accumulation of organic matter; and • Potential to cause odours.
4.2 Objective • To ensure that environmental impacts associated with waste are minimised through
appropriate storage, handling and disposal of all waste produced.
4.3 Applicable Legislation, Policies and References The following legislation applies to waste management: • Soil Conservation and Land Utilization Act 1980;• Waste Management and Pollution Control Act 1998;• Public Health Act 1981;• Dangerous Goods Act 1981; and • Environmental Assessment Act 1982.
Relevant policies, codes of practice and measures includes: • National Environmental Protection (Assessment of Site Contamination) Measure 1999. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soil Management Sub-plan, Water Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan, Weed and Pest Species Management Sub-plan and Air Quality Management Sub-plan are related to this Sub-plan.
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4.4 Risk Assessment Table 6: Risk Assessment for Waste Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Accumulation of filtrate mat from floor of SAT basins requiring disposal
4 3 12 M
Filtrate mat containing high concentrations of heavy metals or toxic organic residues and potential pathogens (e.g. Cyclospora)
2 4 8 L
Generation of putrescible wastes
Creation of odours from organic wastes (primarily from filtrate mat becoming anaerobic)
3 3 9 L
Generation of liquid waste
The generation of minor waste oils from vehicles, operational equipment and pumps
3 2 6 L
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4.5 Management Actions - WasteEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Investigate the possibility of using filtrate mat as abiosolid fertiliser/soil conditioner
Consultation with Office ofEnvironment & Heritage as tosuitability of use as a fertiliser
If testing shows unacceptable levels of pathogens,treat with UV (sunlight) or mix with green wastesand compost (heat kills pathogens and compostingeliminates odours)
Sampling and testing forpathogens, chemicals andheavy metals
Organic wastemanagement
If determined that treatment of filtrate mat is not anoption or concentrations of chemicals and metalsare to high, filter mat is to be disposed of at anapproved licensed waste facility
Power & Water
Adequate transport of wastesoff-site to an approvedlicensed landfill facility whererequired
No odour complaints
Liquid waste control The disposal of waste oils from vehicles,operational equipment and pumps by a wastedisposal contractor
Power & Water Provide adequate transport ofwastes off-site by an approvedwaste disposal contractor
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5 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN
5.1 Issues and Impacts There is the potential for SAT operations to impact on the vegetation and habitats surrounding the site and the native fauna in the area. These potential impacts include:
• Loss or alteration of habitat through changes to groundwater flows and height; • Degradation of the adjacent vegetated areas through air borne dust, changes in hydrology
and compaction; and • Disturbance to fauna on site through the creation of artificial fauna attractants, which may
result in harm to the native fauna, or threaten operations.
5.2 Objectives • To protect Threatened species or any area of environmental or cultural significance; and • Limit the impact upon habitat of native species through management practices.
5.3 Applicable Legislation, Policies and References The following legislation applies to vegetation, fauna and habitat management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Territory Parks and Wildlife Conservation Act 2000;• Weeds Management Act 2001;• Bushfires Act 2004; • Plant Diseases Control Act 2000; and • Soil Conservation and Land Utilization Act 2001.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Weed and Pest Management Sub-plan and Fire Management Sub-plan are related to this Sub-plan.
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5.4 Risk Assessment Table 7: Risk Assessment of Vegetation, Fauna and Habitat Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of vegetation 2 2 4 ILoss of Threatened flora or fauna species 2 4 8 LDisturbance to fauna 3 3 6 L
Impact to vegetation, fauna and habitat
Loss of habitat 2 2 4 I
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5.5 Management Actions - Vegetation, Fauna and HabitatEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Minimise areas cleared during operations andensure operational activities are within boundary ofSAT site and not extending to areas of nativevegetation surrounding siteConfine vehicle movement to boundaries of SATsite to minimise the potential impact on native flora
Training of personnelNative floramanagement
Monitor the effects of repeated vehicle use insusceptible areas to ensure no significant soil andvegetation loss is occurring
Power & Water
Visual inspection of accesstracks and soils
No off-site impacts tovegetation or habitat
Native faunamanagement
Maintain a clean and tidy work area to ensure thatnative fauna are not attracted to the site
Power & Water Provide covered binsFence maintenance
No problems with native faunaspecies scavenging
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6 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN
6.1 Issues and Impacts The introduction of weeds and pest species during the operational phase may cause environmental impacts to the SAT site. Weeds may be introduced from operational activities including the movement of vehicles across site and disturbance of soil. Weeds have the potential to: • Increase the risk of wildfire; • Compete with native plants; • Change the micro-habitat; • Require increased weed control activity; and • Affect visual amenity. The potential issues from pest species during operational activities include: • Increase in feral animal activities on site (including wandering domestic pets, rabbits, feral
cats and the house mouse). This has the potential to interfere with SAT activities. Feral animals can also impact on native flora in the area as well as create unnecessary risks to site operations;
• Potential to attract to the AZRI site problem wildlife that may pose a threat to existing and potential operations and encourage predation on native wildlife; and
• Attraction of flying insects, including mosquitoes, to the site, as the result of unseasonal presence of surface water bodies which can be used for breeding sites. This is an issue because the proposed operations are adjacent to neighbouring residential properties.
Pest species have the potential to adversely affect native fauna through competition for food and nesting or roosting areas, through predation and by adversely affecting fauna habitat though soil disturbance and changing vegetation composition. Pest species may also create health and nuisance risks to adjacent landholders.
6.2 Objectives • To prevent the introduction of new weed species on the site; • To prevent the spread of existing weed species on the site; • To prevent the creation of habitat suitable for pest species; and • To minimise the occurrence of feral animals visiting or residing in the site.
6.3 Applicable Legislation, Policies and References The following legislation applies to weed and pest species management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999;• Territory Parks and Wildlife Conservation Act 2000;• Weeds Management Act 2001;
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• Bushfires Act 2004;• Plant Diseases Control Act 2000; and • Soil Conservation and Land Utilization Act 2001.
Relevant policies, codes of practice and measures include: • Article 20 of the World Health Organisation Regulation; and • NT Medical Entomology Branch Guidelines. Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Fire Management Sub-plan are related to this Sub-plan.
6.4 Risk Assessment Table 8: Risk Assessment for Weeds and Pest Species
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Weed establishment from vegetation clearing and soil disturbance
4 2 8 LWeed establishment or spread Introduction of weed species from vehicles
travelling across site 4 2 8 L
Increased mosquito breeding as result of artificial ponding
3 3 9 LPest species
Loss of native invertebrates due to non-selective mosquito fogging
3 3 9 L
Introduction of feral species
Feral species (including domestic dogs) interfering with site operations
2 2 4 L
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6.5 Management Actions – Weeds and Pest SpeciesEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Monitor weeds as part of the annual sitemaintenance programmeUndertake mechanical or physical control of weedsacross SAT site, as requiredBuffel grass should not be removed in the absenceof another suitable groundcover to maintain soilstability outside of basins
No weed growth in SATbasins
Weed control
When working in weed infested areas, ensurevehicles and equipment are cleaned prior to movingto weed free areas
Power & Water Regular audit/ inspection ofthe site to ensure weedmanagement measures arebeing implemented
No introduction of new weedspecies
Establish and maintain a register to record sightingsof feral animals
Feral animalmanagement
No domestic animals to be brought on to the site
Power & Water Rabbit proof fenceInspection of the site to ensureferal animals have not takenup residence on siteIf increase in population offeral animals – undertake aneradication programme
No feral animals present inSAT site
Pest speciesmanagement
Undertake mosquito monitoring at regular intervalsduring the year. Advice should be sought from theDepartment of Health and Community Services(DHCS) to determine the timing of monitoring fromyear to year and species likely to be encountered
Power & Water Baited mosquito trapsLiaison with DHCS
No increase in mosquitoabundance, as determinedthrough monitoring and/orcommunity complaints
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7 FIRE MANAGEMENT SUB-PLAN 7.1 Issues and Impacts Currently the AZRI site has a well-maintained network of firebreaks and access tracks (minimum 4 m wide) located around the perimeter. The potential impacts of uncontrolled fire for the SAT operations include: • Creation of weed corridors; • Disruption of the current fire management regime; • Loss of existing vegetation and fauna habitat; • Disruption of operational activities; • Damage to infrastructure; and • Potential for injury to SAT workers or other community members.
7.2 Objectives • To prevent uncontrolled wildfire on the site; • To ensure safety of site personnel, surrounding residential areas; and • To protect native vegetation from the impact of hot wildfires.
7.3 Applicable Legislation, Policies and References The following legislation applies to fire management: • Commonwealth Environment Protection and Biodiversity Conservation Act 1999; and • Bushfires Act 2004.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soils Management Sub-plan, Water Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Weed and Pest Species Management Sub-plan are related to this Sub-plan.
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7.4 Risk Assessment Table 9: Risk Assessment for Fire Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of SAT infrastructure and assets 3 4 12 MWeed establishment after fire disturbance 3 3 9 L
Fire
Loss of existing vegetation and fauna habitat 2 3 8 L
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7.5 Management Actions – Fire
Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaContinue with the current policy of fire preventionused on AZRI which includes coordinating with thevolunteer and regular fire-fighters
Update current fire preventionpolicy for new activitiesundertaken on SAT site
Continue maintenance of fire breaks around AZRIsite
DBIRD
Maintenance of firebreaks onannual basis
Prevent the use of open firesMaintain any newly established internal firebreakson the SAT site
Fire management plan andconsultation with DBIRD
All site personnel are to be inducted into fire risk,prevention and management
Fire management
Have fire fighting equipment in strategic locationsacross site and in vehicles
Power & Waterin consultation
with DBIRD
Induction and training of sitepersonnel
No increase in incidence ofwildfireWildfires not originating fromAZRI siteFirebreaks maintainedPersonnel aware of firemanagement techniques
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8 AIR QUALITY MANAGEMENT SUB-PLAN 8.1 Issues and Impacts Air quality issues can occur as the result of SAT operations. These issues include: • Dust creation from vehicles travelling across site; and • Odours, from the recycled water and storage of filtrate mats on site. The impacts associated with these issues include: • Production of nuisance dust emissions which can potentially cause:
o Airborne dust settling on employee vehicles, o Dust generated from the site activities can create health (respiratory) issues for
workers and adjoining site users (including neighbouring residential area); and o Dust settling on the local drainage channels increasing turbidity and reducing the
transfer of oxygen between air and water; and • Odours diminishing the quality of life for surrounding residents.
8.2 Objectives • To manage air emissions from the SAT site operations, particularly nuisance dust and
odours; and • Comply with air quality standards as defined by Commonwealth and Northern Territory
legislation.
8.3 Applicable Legislation, Policies and References The following legislation applies to air quality management: • Ozone Protection Act 1990;• Dangerous Goods Act 1981;• Waste Management and Pollution Control Act 1998; and • Work Health Act 1986. Relevant policies, codes of practice and measures include: • National Health and Medical Research Council (NHMRC) Guidelines for Air Quality; • National Exposure Standards for Atmospheric Contaminants in the Occupational
Environment (NOHSC, 1003); • Air Quality Standards AS/NZS 3580.10.1:2003 - Methods for sampling and analysis of
ambient air; • Australian Standard AS2985-2004 workplace atmospheres-method for sampling and
gravimetric determination of respirable dust; • Australian Ventilation Standard AS 1666.2; and • Occupational Health and Safety Regulations and advisory standards.
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Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme. The Soil Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Access and Public Safety Management Sub-plan are related to this Sub-plan.
8.4 Risk Assessment Table 10: Risk Assessment for Air Quality Issues
Nuisance dust impacting on nearby residences 5 3 15 HNuisance dust impacting on site workers 5 3 15 HImpact from nuisance dust on adjacent vegetated areas
3 2 6 L
Dust
Increasing turbidity and reducing the transfer of oxygen between air and water from dust settling on the local drainage channels
2 2 4 I
Odour Impact on the aesthetics of the surrounding area 2 2 4 I
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8.5 Management Actions – Air QualityEnvironmental Controls Mitigation and Management Responsibility Resources Performance Criteria
Restrict movement on boundary firebreaks to thatrequired for AZRI property management
Regular road and trackmaintenance
High use roads should be constructed to minimisedust generation
Maintenance of access roads
A maximum speed limit of 20 km/h will be imposedwithin the site to control generation of dust byvehicles moving through operation areas
Meets the NHMRC Guidelinesfor Air Quality
Daily assessment of weather conditions Register of daily windconditions
During periods of high winds when soil moisture islow, additional precautions will need to beundertaken to protect exposed surfaces. Thesemay include increased frequency of watering andcessation of site operations during strong windswhich are likely to mobilise soils and dust,especially if winds are blowing towards sensitivereceiving areas (e.g. residential area)Ensure all exposed soils are stabilised, includingbasin walls
Mulching machine
Dust generating activitiesceased or suppressionmeasures implemented whenstrong winds present
Management ofnuisance dustemissions
Record any dust complaints
Power & Water
Maintain a dust complaintsregister
No dust complaints
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Environmental Controls Mitigation and Management Responsibility Resources Performance CriteriaMaintain a 100 m buffer between residential areasand the SAT basinsTertiary treatment (Dissolved Air Flotation andchlorination) of wastewater prior to delivery ofrecycled water product to AZRI and SAT basins,and further polishing through SATRecycled water will be stored in undergroundaquifers which will reduce the potential for odourissues to occur
Odour management
Record any odour complaints
Power & Water Maintain an odour complaintsregister
No odour complaints
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9 ACCESS AND PUBLIC SAFETY MANAGEMENT SUB-PLAN
9.1 Issues and Impacts There is a risk that visitors (authorised and unauthorised) may access the SAT operation site. This can potentially create liabilities for SAT operation management. The potential impacts associated with SAT operations include: • Insecure areas may result in members of the public harming themselves; and • Insecure areas may result in operational equipment being damaged.
9.2 Objectives • To minimise the risk of injury to authorised and unauthorised persons; and • To minimise the risk of unauthorised persons harming SAT operational equipment.
9.3 Applicable Legislation, Policies and References The following legislation applies to access and public safety management: • Dangerous Goods Act 1981; and • Work Health Act 1986.
Relevant reports and documents include: • Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and • SAT Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
9.4 Risk Assessment Table 11: Risk Assessment for Access and Public Safety
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Visitors (authorised and unauthorised) on site harming themselves
3 3 9 LSite Access
Visitors (authorised and unauthorised) on site causing damage to operational equipment
3 3 9 L
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9.5 Management Actions – Access and Public Safety Environmental Controls Mitigation and Management Responsibility Resources
Ensure site equipment is stored appropriately Maintain a site OH&S Policy Establish a visitor register Signpost all recycled water outlets, clearly stating water is not for drinking
Access and public safety management
Maintain entry signage
Power & Water Personnel to maintain policy and visitor registerSignage materials, equivalent to existing signage used by Power and Water to indicate recycled wate
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10 INDUCTION TRAINING REQUIREMENTS The purpose of induction training is to ensure that all personnel who are engaged in the operation of the SAT scheme are aware of their environmental obligations. The Power and Water Corporation site manager will be responsible for the conduct of environmental induction training for all persons working on site, including any subcontractors. An experienced and qualified environmental trainer is to undertake environmental induction training for all personnel involved in the construction of the SAT site. It is proposed that the environmental induction training for site personnel and sub-contractors can be undertaken at two levels: 1. Complete induction - training for personnel who will be on site for more than five days or
those personnel on site for less than five days but involved in activities that have the potential to cause environmental harm (e.g. installation and maintenance of erosion and sediment control devices, clearing and grubbing, felling of trees, earthworks, stabilising disturbed surfaces).
2. Quick induction - training for personnel that will be on site for less than five days and are undertaking activities that do not have the potential to cause significant environmental harm.
An induction training programme for both induction levels needs to be developed. The induction training for both levels should cover the same issues. The difference between the two induction courses is the level of training provided for each issue. The issues to be addressed in induction include (but are not limited) to the following: • Awareness of the SAT OEMP; • Awareness of general environmental duties under the relevant Acts and the consequences
of any breaches; • An overview of what constitutes an environmental incident and the appropriate person to
notify in the event of an environmental incident; • General awareness of the environmental and cultural significance of the adjacent local
drainage channels, vegetation corridors and buffer area; • Location of No Go areas, particularly St Mary’s Creek, the buffer area and recognised
cultural areas; • Specific practices required for erosion and sediment control; • General flora and fauna management; • Speed limit restrictions throughout the site; • Procedures to follow and who to contact in the case of a hydrocarbon or other hazardous
substance spill; • The location and use of fire extinguishers/hydrants; • Appropriate waste management practices; • Awareness and understanding of non-drinking water signage; and • The appropriate person to notify in the event that any environmental mishaps occur. The environmental induction training can be undertaken alongside the OH&S training.
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11 MONITORING FRAMEWORK Monitoring is the systematic collection of data and information in relation to specific environmental issues or conditions. The main purposes of monitoring are: • To identify trends and changes over time and between areas to enable identification of
measures to improve environmental practices and performance; and • To assist in the identification of non-predicted impacts. There are two main areas that can be monitored, environmental condition and environmental management.
11.1 Environmental Condition Monitoring of environmental condition will establish whether the recommended practices in this EMP are effective in achieving their desired environmental outcome and will allow for the detection of non-predicted impacts. The principle issues requiring monitoring during the SAT operations relate to: • Changes to groundwater level and chemistry:
o Increasing groundwater levels and potential lateral movement due to possible perched conditions below the SAT basins that could result in water logging and surface water discharge;
o Mixing of infiltrated recycled water and existing groundwater and anticipated improvements to groundwater quality and subsequent suitability for extraction and reuse;
o Groundwater flow and quality within alluvial sediments outside the immediate SAT scheme area; and
o Increased migration of existing saline groundwater present in alluvial sediments through poorly constructed or old bores used to extract groundwater from underlying Tertiary sediments within the AZRI site and adjacent rural residential properties;
• Change to soil properties; • Quality and quantity of recycled water received from the pipeline; • Complaints received from neighbouring properties from nuisance dust, excessive noise
and odours caused by SAT operations; and • Increase in the number of mosquitoes/biting insects.
11.1.1 Groundwater Monitoring Monitoring of groundwater, commenced during the construction phase, should be continued during the operational phase. Monitoring of the groundwater will be from four distinct levels within the subsurface: • Alluvial Layer 2: Within the more porous and permeable layer of sands and gravel to
typical depths of 3 m to 5 m; • Alluvial Layer 4: Within the more porous and permeable layer of silty sand and gravel
located above the main low permeability clay cap overlying the paleochannel to typical depths of 9 m to 11 m;
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• Alluvial Layer 6: Within both the main paleochannel to depths of approximately 30 m and the more widespread layer outside the paleochannel to depths of approximately 20 m; and
• Tertiary Aquifers: Within the upper thin layers of sand material located at depths of approximately 50 m and greater below the overlying sequence of low permeability clays.
Monitoring these levels of groundwater will demonstrate that the objectives of enhanced water treatment, environmental protection and opportunities for reuse are achieved and will support the ongoing effective and efficient management of the SAT scheme. The monitoring bore network will be developed during the SAT CEMP. It is expected that these monitoring bores will be located in the following areas: • Immediately below the SAT infiltration basins (nominally four sets of bores); • Immediately adjacent to the SAT infiltration basins (nominally six sets of bores); • Adjacent to the aerial extent of the paleochannel feature within the AZRI site around the
infiltration basins (nominally six sets of bores); and • Adjacent to the boundary of the AZRI site with the rural residential properties, Colonel
Rose Drive and Todd River and an equivalent distance to the west of the infiltration basins within the AZRI site (nominally eight sets of bores).
The migration of relatively saline groundwater down existing extraction bore annuluses will also require monitoring and the most appropriate monitoring locations for this will be using the existing monitoring bores where access is available. The monitoring programme will include each of the existing Tertiary extraction wells located within the AZRI site and a representative selection of six extraction wells within the adjacent rural residential properties. A sampling and analysis programme will be established prior to the commencement of infiltration to measure ambient groundwater concentrations. The sampling and analysis programme will be undertaken for a suite of contaminants including major ions, metals and nutrients (Table 15).
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Table 13: Groundwater Monitoring during SAT Operation Parameter Suggested Determinants Frequency of
testing / year Site(s)
Heavy Metals Al, As, B, Cu, Cd, Cr, Zn (as minimum suite)
2 Monitoring bores
Dominant ions Ca, Na, K, Cl, SO4, HCO3. 4 Infiltration ponds and monitoring bores
TDS Conductance (25°C). Calculation based on above.
12 Infiltration ponds and monitoring bores
Organics Pesticides, MBAS, TOC and DOC
1 Infiltration ponds and monitoring bores
Field determinations pH, turbidity, temperature, dissolved oxygen, ORP
12 Infiltration ponds and monitoring bores
Oxygen demand BOD, COD 12 Infiltration ponds and monitoring bores
Bacteriological indicators
Coliforms and E. coli 12 Infiltration ponds and monitoring bores
Pathogen indicators C. perfringens, viruses 2 Infiltration ponds and monitoring bores
Nutrients Total and dissolved P, Total N, TKN, NOx
2 Infiltration ponds and monitoring bores
11.1.2 Soil Testing Testing of the soil in the SAT basins will be undertaken on a monthly basis for the first three years of operations and then quarterly for the following three to five years. The testing of the soils in the SAT basins will require the sampling of a minimum of five samples from each of four depths (outlined in Table 16) in each SAT sub-basin. These can then be combined to make one bulk sample from each depth (total of four samples sent to laboratory for analysis). The analysis of the combined soil samples should be undertaken by a NATA certified laboratory to provide independent data assessment. The Exchangeable Sodium Percentage will be calculated from the results of laboratory tests on the CEC (Table 16).
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Table 14: Soil Testing on the SAT Basins for First Year of Operation Parameter Units Depth Frequency of
testing / year Nutrients (Total and available P, TKN, N and NH4)
mg/L Monthly
pH Monthly Electrical Conductivity uS/cm Monthly Organic Carbon % Bi-annually Cations (Ca, MG, K, Al, Na) Mg/L Monthly Cation Exchange Capacity (CEC) cmol(+).k
gMonthly
Sodium Adsorption Ration (SAR) : Monthly Exchangeable Sodium Percentage (ESP) of CEC
%
0-100 mm 100-300 mm 300-600 mm
600-1,000 mm
Monthly
11.1.3 Monitoring of Recycled Water Entering SAT Basin The recycled water coming from the pipeline into the SAT basins will be monitored for quality and quantity. It is expected that in-line monitoring will occur for: • Water Quality Monitoring, continuous or routine analysis of waste water:
o TDS - salinity levels in irrigation water. If concentrations exceed the recommended levels in the recycled water use guidelines, there should be an automatic shut-down of the recycled water supply (alarm to inform operator);
o EC; o pH; o Nutrients - P and N; o Biological Oxygen Demand (BOD); o Heavy metals; o Thermo-tolerant Coliforms; and o Chlorine residue;
• Water Quantity Monitoring: o Water level of SAT Basin; and o Inflow rate of recycled water entering SAT basins.
11.1.4 Dust, Noise and Odour Complaints monitoring Dust, noise and odours are not expected to adversely impact on neighboring stakeholders as long as SAT operation safeguards identified in this EMP are in place. The creation of an environmental complaints register and the investigations of any complaints received will be maintained. The complaints register should report the following information: • Date and time of complaint; • Date and time of incident;
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• Location; • Weather data to determine wind speed and direction to assist in identifying source of
nuisance; • Type of complaint – noise, dust or odour; • Description of complaint; • Contact details of complainant; • Who recorded complaint; • Who was responsible for investigating complaint; and • Results and outcome for investigation and follow up. If all safeguards and control measures for noise, dust or odours fail and complaints have been received, monitoring of these emissions should be undertaken. The monitoring activities for dust, noise and odour are described below: • Dust monitoring will be undertaken following the Air Quality Standards AS 3580.10.1:2003 -
Methods for sampling and analysis of ambient air. The siting of the air sampling units will require one in the location of the complainant and a background unit located upwind of the SAT site;
• Environmental noise monitoring will be undertaken in accordance with the AS 1055.1:1997 Acoustics—Description and measurement of environmental noise, which sets out general procedures for the description and measurement of environmental noise including repetitive impulsive noise and AS 1055.2:1989 Application to specific situations; and
• Monitoring odour is slightly more difficult, as odour recognition is a sensation resulting from the reception of a stimulus by the olfactory sensory system. The human response to an odour is only able to be evaluated depending on the particular sensory property that is being measured, including the intensity, detectability, character, and hedonic tone of the odour. The combined effect of these properties is related to the annoyance that may be caused by the odour. Therefore if a number of complaints are received from the adjacent residential area (approximately 10% of the effected population) measures will be undertaken to identify the source of the odour and investigate ways to mitigate and manage.
11.1.5 Mosquito / Biting Insect Monitoring A vital part of a mosquito control programme is the surveillance of the site’s mosquito population. A surveillance programme will determine if mosquito control programmes are achieving population reduction or, more importantly, achieving reductions in pest problems and/or mosquito borne diseases. There are four stages to mosquito surveillance which includes1:• Preliminary Phase – defines the nature and extent of an on site mosquito problem. It
would include an information search, drawing a vector control map and initial sampling of adult and larval mosquitoes;
• Base line Data Phase – involves at least a 12 month programme, requiring regular sampling of the permanent larval and adult sampling points, collating climatic data and recording changes to mosquito habitat. This stage should also provide plans for control strategies for disease and vector control;
1 Whelan, P. 2004. Mosquito Surveillance and Monitoring Techniques. In Mosquito Management Manual, Department of Health Western Australia
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• Operations Phase – from the implemented mosquito control programme, regular larval and adult surveys should continue. These ongoing surveys (at the same sampling points) will indicate status of adult and larval populations in the control area. Occasionally complaints from community members may require additional and supplementary larval and adult sampling data to assist in determining the reason for increased mosquito population; and
• Evaluation Phase – after control measures have been carried out, it is most important to assess their effectiveness and to identify any remaining problems.
11.2 Environmental Management In addition to monitoring environmental conditions, it is also important to monitor the development and implementation of the environmental management processes within the SAT operations. Environmental management is the process by which the operators of the SAT scheme can ensure compliance to environmental legislation and minimise environmental risks. Environmental management monitoring for the SAT operations is as follows: • Undertake periodic reviews and auditing of SAT activities to ensure management actions
are being carried out; and • Periodic reviews and audit of SAT operations using the management action tables
provided in this EMP as a checklist, to ensure all environmental measures are being implemented.
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12 AUDITING Environmental auditing is an integral part of the environmental management of the SAT operations. It is an important management tool that is a systematic, documented, periodic and objective evaluation of the environmental management practises on site. The audit assists in verifying how well the operation is performing against the OEMP and processes, to determine the level of compliance with the nominated environmental criteria. Environmental auditing should be seen as an opportunity for the continual improvement of management practises at the site. It should also be conducted during any or all stages of the proposed activities and can be undertaken in conjunction with other system audits, such as workplace health and safety, quality and contract administration, or it can be undertaken as a separate environmental audit.
12.1 Periodic Review Periodic reviews throughout the lifetime of the SAT operation activities are required to ensure the measures set in the OEMP are being implemented. The periodic review will be undertaken by the relevant responsible bodies as described in the management sub-plans. The periodic review of operational activities will be undertaken in the form of an informal inspection. The objectives of the review are to identify: • Physical aspects of the operations which are not in compliance with the set requirements of
this OEMP; and • Any aspects of the SAT operation that may have caused or have the potential to cause
environmental harm. While these inspections will be less rigorous than actual environmental audits, they play an important role in identifying non-conformances that may require immediate remedial action. These inspections can also be important mechanism for identifying areas that may need to be audited in the future. The informal inspections should be undertaken throughout the life of the operational activities at least once per week (depending on the activities taking place on site); particularly during key developmental stages or activities, such as: • The maintenance of SAT basins including the removal and disposal/reuse of filtrate mat
material; • The weekly wet/dry cycle of SAT basins; • During heavy rainfall events to monitor run-off from site; and • Removal of waste materials from site.
12.2 Environmental Audit It is recommended that environmental audits be undertaken during the operation of the SAT scheme. It is recommended that audits be undertaken at the same time corporate environmental reporting is undertaken, to integrate this process with existing environmental practises. Audits can be undertaken by relevant, trained members of an organisation’s own staff (i.e. Environmental Officer) or by external, professional auditor. The main types of audits which are recommended to be undertaken during the SAT operations include:
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• Compliance Audits - these audits are undertaken against this OEMP. The compliance audit is similar to the periodic review only it will be more thorough and the audit will be conducted by someone external to the process. It is recommended that compliance audits be undertaken bi-annually; and
• Formal Audits - these examine the environmental impacts associated with operational activities. These audits assist operators to understand not only the environmental impacts of the operations but also how its processes and activities contribute to the impacts. Formal audits will enable a continual review and update of strategies and identify any changes to legislation, regulations or policies for site operations.
12.3 Non-conformance Procedures Non-conformance procedures are those procedures that should be followed in the event that a site audit or inspection identifies a breach of the agreed environmental management strategies has occurred. These procedures apply to all personnel including any sub-contractors. In the event of a non-conformance, the following procedure should be followed: • Non-conformance activity should cease; • Contact the Operations Manager, who will then contact the Environment Manager, Safety
Officer or other personnel as required; • Assess the degree of non-conformance and extent of resultant environmental impact; • Determine procedures for mitigation or management; and • Undertake management or mitigation procedures to the satisfaction to the Environment
Officer. Each non-conformance should be documented, along with the corrective actions undertaken
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Appendix 10: Operation Environmental Management Plan Horticulture Scheme
Horticulture Operation Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005
Prepared for: Power and Water CorporationPO Box 1521 ALICE SPRINGS NT 0871
Report by: HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia Ph: +61 8 8935 0515 Fax: +61 8 8932 5369
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05.doc
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
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DISTRIBUTION
Horticulture Operation Environmental Management Plan Alice Springs Water Reuse Scheme 11 April 2005
Copies Recipient Copies Recipient 1 Mark Skinner
Senior Project Manager PO Box 1521 ALICE SPRINGS NT 0871
This document was prepared for the sole use of Power and Water Corporation and the regulatory agencies that are directly involved in this project, the only intended beneficiaries of our work. No other party should rely on the information contained herein without the prior written consent of HLA-Envirosciences Pty Limited and Power and Water Corporation.
By
HLA-Envirosciences Pty Limited ABN: 34 060 204 702 Suite 4-5, 58 Georgina Crescent Palmerston NT 0830 PO Box 3800 Palmerston NT 0831 Australia
____________________________________
Alana Eggleton Environmental Scientist
Peer Review: Date:
11 April 2005
Dr Sandy Griffin Principal Environmental Scientist
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CONTENTS 1 THE HORTICULTURAL OPERATIONAL EMP............................................................ 1
1.1 Introduction ..................................................................................................... 1
1.2 Background..................................................................................................... 1
1.3 Purpose........................................................................................................... 2
1.4 Risk Assessment ............................................................................................ 2
1.5 Management Strategies.................................................................................. 3
2 SOIL AND EROSION MANAGEMENT SUB-PLAN ..................................................... 4
2.1 Issues and Impacts......................................................................................... 4
2.2 Objectives ....................................................................................................... 4
2.3 Applicable Legislation, Policies and References ............................................ 4
2.4 Risk Assessment ............................................................................................ 5
2.5 Management Actions – Soil and Erosion........................................................ 6
3 WATER MANAGEMENT SUB-PLAN ......................................................................... 10
3.1 Issues and Impacts....................................................................................... 10
3.2 Objectives ..................................................................................................... 10
3.3 Applicable Legislation, Policies and References .......................................... 10
3.4 Risk Assessment .......................................................................................... 11
3.5 Management Actions – Water ...................................................................... 12
4 WASTE MANAGEMENT SUB-PLAN ......................................................................... 14
4.1 Issues and Impacts....................................................................................... 14
4.2 Objectives ..................................................................................................... 14
4.3 Applicable Legislation, Policies and References .......................................... 15
4.4 Risk Assessment .......................................................................................... 15
4.5 Management Actions – Waste...................................................................... 16
5 HAZARDOUS SUBSTANCES SUB-PLAN................................................................. 18
5.1 Issues and Impacts....................................................................................... 18
5.2 Objectives ..................................................................................................... 18
5.3 Applicable Legislation, Policies and References .......................................... 18
5.4 Risk Assessment .......................................................................................... 19
5.5 Management Actions - Hazardous Substances ........................................... 20
6 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN ...................... 22
6.1 Issues and Impacts....................................................................................... 22
6.2 Objectives ..................................................................................................... 22
6.3 Applicable Legislation, Policies and References .......................................... 22
6.4 Risk Assessment .......................................................................................... 23
6.5 Management Action - Vegetation, Fauna and Habitat ................................. 24
7 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN ..................................... 25
7.1 Issues and Impacts....................................................................................... 25
7.2 Objectives ..................................................................................................... 25
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 iii
7.3 Applicable Legislation, Policies and References .......................................... 25
7.4 Risk Assessment .......................................................................................... 26
7.5 Management Actions - Weeds and Pest Species ........................................ 27
8 FIRE MANAGEMENT SUB-PLAN .............................................................................. 29
8.1 Issues and Impacts....................................................................................... 29
8.2 Objectives ..................................................................................................... 29
8.3 Applicable Legislation, Policies and References .......................................... 29
8.4 Risk Assessment .......................................................................................... 30
8.5 Management Actions – Fire.......................................................................... 31
9 HERITAGE MANAGEMENT SUB-PLAN.................................................................... 32
9.1 Issues and Impacts....................................................................................... 32
9.2 Objectives ..................................................................................................... 32
9.3 Applicable Legislation, Policies and References .......................................... 32
9.4 Risk Assessment .......................................................................................... 33
9.5 Management Actions – Heritage .................................................................. 34
10 AIR QUALITY MANAGEMENT SUB-PLAN ............................................................... 35
10.1 Issues and Impacts....................................................................................... 35
10.2 Objectives ..................................................................................................... 35
10.3 Applicable Legislation, Policies and References .......................................... 35
10.4 Risk Assessment .......................................................................................... 36
10.5 Management Actions - Air Quality ................................................................ 37
11 NOISE MANAGEMENT SUB-PLAN ........................................................................... 40
11.1 Issues and Impacts....................................................................................... 40
11.2 Objectives ..................................................................................................... 40
11.3 Applicable Legislation, Policies and References .......................................... 40
11.4 Risk Assessment .......................................................................................... 41
11.5 Management Actions – Noise....................................................................... 42
12 ACCESS AND PUBLIC SAFETY MANAGEMENT SUB-PLAN................................. 43
12.1 Issues and Impacts....................................................................................... 43
12.2 Objectives ..................................................................................................... 43
12.3 Applicable Legislation, Policies and References .......................................... 43
12.4 Risk Assessment .......................................................................................... 44
12.5 Management Actions - Access and Public Safety ........................................ 45
13 INDUCTION TRAINING REQUIREMENTS................................................................. 46
14 MONITORING FRAMEWORK..................................................................................... 47
14.1 Environmental Condition............................................................................... 47
14.1.1 Groundwater Monitoring................................................................ 47
14.1.2 Monitoring of Recycled Irrigation Water from Extraction Bores ............................................................................................. 48
14.1.3 Soil Testing.................................................................................... 49
14.1.4 Wastewater from Fruit Packing System ........................................ 49
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 iv
14.1.5 Vegetation, Habitat and Fauna monitoring.................................... 50
14.1.6 Dust, Noise, Spraydrift and Odour Complaints Monitoring ........... 50
14.1.7 Mosquito/Biting Insect Monitoring ................................................. 51
14.2 Environmental Management......................................................................... 51
15 AUDITING.................................................................................................................... 52
15.1 Periodic Review ............................................................................................ 52
15.2 Environmental Audit...................................................................................... 52
15.3 Non-conformance Procedures...................................................................... 53
TABLES
Table 1: The qualitative measure of likelihood .............................................................................2Table 2: The qualitative measure of consequence.......................................................................3Table 3: Risk assessment scoring................................................................................................3Table 4: Risk Assessment for Soil and Erosion Issues................................................................5Table 5: Risk Assessment for Water Management Issues ........................................................11Table 6: Risk Assessment for Waste Issues ..............................................................................15Table 7: Risk Assessment for Hazardous Substance Issues.....................................................19Table 8: Risk Assessment for Vegetation, Fauna and Habitat Issues .......................................23Table 9: Risk Assessment for Weeds and Pest Species ...........................................................26Table 10: Risk Assessment for Fire Issues ................................................................................30Table 11: Risk Assessment for Heritage Issues.........................................................................33Table 12: Risk Assessment for Air Quality Issues......................................................................36Table 13: Risk Assessment for Noise Issues .............................................................................41Table 14: Risk Assessment for Access and Public Safety.........................................................44Table 15: Groundwater Monitoring during Horticulture Operations............................................48Table 16: Soil Testing in Irrigation Area .....................................................................................49
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 1
1 THE HORTICULTURAL OPERATIONAL EMP
1.1 Introduction This Operational Environmental Management Plan (OEMP) has been prepared for the operational phase of a horticultural venture at the Arid Zone Research Institute (AZRI), located approximately 10 km south of Alice Springs, Northern Territory.
The Public Environment Report (PER) Guidelines issued by the Office of Environment and Heritage (OEH) required the submission of four EMPs to accompany the PER. This OEMP has been developed in accordance with the guidelines of the PER.
A detailed description of the proposed Alice Springs Water Reuse Scheme is provided in the Public Environment Report, which accompanies this OEMP. This OEMP outlines the measures to manage the environmental integrity of the site during operation of the horticulture scheme. The principal objective of the OEMP is to provide effective and practical management strategies that will avoid, ameliorate or mitigate potential adverse impacts associated with the proposed operational phase of the horticultural venture. The OEMP includes clear instructions for management, monitoring and performance evaluation and is guided by the relevant legislation and other codes of practice.
1.2 Background It is proposed that a horticultural venture will be established within the AZRI site, using 1,000 ML per annum of recycled water and operate via a public/private partnership with a selected horticultural company. The proposal is for wastewater originating from the Alice Springs Wastewater Treatment plant to be pre-treated through a Dissolved Air Flotation system, piped to AZRI and then further treated through Soil Aquifer Treatment. Once the recycled water has been stored in the groundwater aquifer below, it is extracted and then used for irrigation.
The horticulture scheme includes a plan to develop 20 ha per year in 4 ha operational blocks over five years, resulting in a total horticultural area of 100 ha. Operation of the horticultural scheme will primarily involve:
• Extraction of recycled water from nearby bores for irrigation;
• Horticultural/agricultural practices including harvesting. Potential crops include fruit (grapes, citrus) and vegetables (asparagus);
• Fertiliser, pesticide and herbicide storage and application;
• Packaging and cold storage of produce from the site;
• Site maintenance works, crop management and management of infrastructure, roads and equipment. Maintenance will potentially include the following areas:
o Maintenance of a groundwater monitoring programme and environmental monitoring programmes including soil monitoring;
o Weed control;
o Maintenance of buffer zones;
o Soil management; and
o Waste management procedures.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 2
1.3 Purpose The horticultural OEMP aims to:
• Provide details of the proposed measures to prevent or minimise adverse impacts and assess the likely effectiveness of these safeguards;
• Ensure that safeguards are being effectively applied;
• Enable remedial action for any impacts that were not anticipated in the PER;
• Determine the differences between predicted and actual impacts (via monitoring); and
• Provide for the periodic review of the management plan itself.
The OEMP provides an ongoing interactive process for defining, documenting and improving the environmental management of the operations for the horticultural scheme. The OEMP is intended to be a ‘living’ document which allows for it to be continuously updated reflecting feedback from the reporting conducted under the plan and recommendations arising from monitoring and audits. This OEMP is accompanied by a Construction EMP (CEMP) for the construction of the site. The CEMP addresses the management of environmental impacts associated with construction activities.
1.4 Risk Assessment A risk assessment, based on AS4360:1999 Risk Management, was undertaken on the potential environmental incidences that may arise during operational activities for the horticultural scheme. The risk assessment combines (qualitative) estimates of the likelihood of a certain event or environmental impact occurring (Table 1) and the consequence (Table 2).
Table 1: The qualitative measure of likelihood
Level Descriptor Description 1 Rare Environmental impact may occur only in exceptional
circumstances
2 Unlikely Environmental impact could occur at some time based on current practices
3 Moderate Environmental impact has a moderate probability of occurring based on current practices
4 Likely Environmental impact will probably occur based on current practices
5 Almost Certain Environmental impact is expected to occur in most circumstances or is already occurring
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 3
Table 2: The qualitative measure of consequence
Level Descriptor Description 1 Insignificant Negligible short term environmental impact to habitat with no
monitoring required
2 Minor Some short term environmental disturbance with localised impacts, some management required
3 Moderate Obvious environmental impact to habitat, more widespread effects, normal incident management response is sufficient
4 Major Substantial environmental harm, loss of immediate habitat, widespread side effects over extended time, long term remediation management required, external agencies utilised
5 Catastrophic High degree of environmental harm, permanent loss of widespread habitat, loss of species, external agencies utilised, incident of regional significance
The likelihood of an event occurring is multiplied by the environmental consequence in order to determine the significance of the impact and, hence, its priority for management (Table 3).
Table 3: Risk assessment scoring
Score Management required 25 Extreme risk: immediate action required to intervene and prevent incident.
15 – 20 High risk: prompt senior management attention of potential environmental impact.
10 – 14 Moderate risk: high priority issue requiring regular management and monitoring.
6 – 9 Low risk: low priority issue that can be managed by routine procedures
1 – 5 Insignificant risk: issue of low importance not requiring management but only occasional monitoring.
The results of the risk assessment have been provided in each aspects sub-plan.
1.5 Management Strategies The following sections provide a description of each aspect or activity that has the potential to impact on the environment and strategies for the management of these potential impacts. Reference has been made to the appropriate section of the PER, where appropriate.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 4
2 SOIL AND EROSION MANAGEMENT SUB-PLAN
2.1 Issues and Impacts Soil management during the horticultural operations will primarily involve management of soil chemistry and erosion and general operational and maintenance activities which are proposed to occur on the site. The potential impacts associated with the horticultural operation activities on soils include:
• Increase in soil salinity and sodicity as a result of soils receiving sodium from the irrigation water. This may lead to changes in the physical and chemical properties of soils, resulting in soils:
o Being more prone to dispersion and erosion;
o Having a coarser structure;
o Having a higher density; and
o Having a lower hydraulic conductivity;
• Increase in the risk of soil compaction (which may impede plant growth) and erosion, because the soils across AZRI are generally light. The horticultural venture is located within land units which are considered to have a very good capability for shallow excavations and horticulture, but have high (land unit 4.06) and severe (land unit 4.09) erosion risks (refer to Figure 11 of the PER for the distribution of land units within AZRI);
• Nutrient loading of soils from phosphorous and nitrogen in the recycled water;
• Contamination of soils from hydrocarbons and other chemicals (herbicides and pesticides) from their storage, handling and use on site;
• Potential for windblown sediments (dust) to be transported off-site from vehicular movement across unsealed roads and site operation works; and
• Use of fill from off-site with the potential to contain weed seeds and contaminants. If fill is stockpiled on site it has the potential to create a dust hazard.
2.2 Objectives
• To prevent degradation of soil during horticultural activities;
• To minimise soil erosion across the horticultural site;
• To minimise dust impacts from general horticultural operations;
• To minimise sedimentation of the sensitive receiving waters of local drainage channels and tributaries such as St Mary’s Creek and the Todd River; and
• To implement measures for the rehabilitation of any degraded areas.
2.3 Applicable Legislation, Policies and References The following legislation applies to soil and erosion management:
• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;
• Soil Conservation and Land Utilization Act 1980;
• Water Act 1992; and
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 5
• Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures include:
• The Northern Territory Procurement Code (National Code of Practice for the Construction Industry adapted for specific application in the Northern Territory); and
• National Environmental Protection (Assessment of Site Contamination) Measure 1999.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 59 to 77; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Vegetation, Fauna and Habitat Management Sub-plan, the Air Quality Sub-plan and the Access and Public Safety Sub-plan are related to this Sub-plan.
2.4 Risk Assessment Table 4: Risk Assessment for Soil and Erosion Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequenc
Total
Priority
Increase in soil salinity and sodicity 4 4 16 H
Changes to soil nutrients 4 4 16 H
Changes to soil pH 3 3 9 L
Soil contamination through application of chemicals 3 3 9 L
Chemical changes of soil / pollution of soil
Contamination of soils from fuel and chemical handling, storage and spills
3 2 6 L
Accelerated erosion from vehicle movement on site as a result of operation
3 3 9 LErosion of soil
Sedimentation of St Mary’s Creek should rainfall events occur during operations, causing loose soil to be washed into creek channels
2 2 4 L
Generation of dust by vehicle movement and general operations (i.e. planting and harvesting)
3 3 9 LCreation of Dust
Increasing turbidity and reducing transfer of oxygen from air to water as the result of dust settling on local drainage channels
3 3 9 L
Compaction of Soils
Compaction of soils from heavy vehicle movement across site. Compaction of soil may impact on the ability of plants to grow
4 2 8 L
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scap
ing
equi
pmen
t
Lim
itth
enu
mbe
rofv
ehic
les
and
earth
mov
ing
equi
pmen
ttra
vellin
gac
ross
site
tow
hati
sne
cess
ary
Reg
ular
road
and
track
mai
nten
ance
Com
pact
ion
Rem
edia
tean
yar
eas
whi
chha
vebe
enim
pact
edby
rip/fu
rrow
/aer
atio
nof
the
impa
cted
soils
Hor
ticul
tura
list
Rem
edia
tion
ofso
ils
Reg
ular
audi
t/in
spec
tion
ofth
esi
teto
ensu
reno
sign
ifica
ntco
mpa
ctio
nof
soils
isoc
curr
ing
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
9
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Ifst
ockp
ileof
soil
orot
herm
ater
ials
onsi
teis
requ
ired,
shou
ldbe
inco
njun
ctio
nw
ithth
esi
tere
quire
men
ts
Ensu
rest
ockp
ileis
stab
leby
unde
rtaki
ngap
prop
riate
cont
rols
mea
sure
s,i.e
.cov
erw
ithta
rpor
othe
rsta
bilis
ing
agen
t
Stoc
kpile
man
agem
ent
Ensu
rest
ockp
iles
are
>50
maw
ayfro
mlo
cal
drai
nage
Cor
ridor
san
dne
ighb
ourin
gpr
oper
ties
Hor
ticul
tura
list
Prov
ide
ade
sign
ated
area
for
stoc
kpilin
gD
ustr
esul
tsar
ew
ithin
rele
vant
envi
ronm
enta
ldus
tcr
iteria
(NEP
M)
No
dust
com
plai
nts
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 10
3 WATER MANAGEMENT SUB-PLAN
3.1 Issues and Impacts There are four main sources of water that exist or may be generated on site during horticultural operations. These include:
• Groundwater - the horticulture operation has the potential to cause changes in the groundwater height (water logging) and chemistry (salinity) and can result in the diversion of natural groundwater flows. Groundwater contamination may also occur from a number of site activities such as accidental spills and/or leakages on site from toxic or hazardous substances or from the mixing of recycled water in the palaeochannel;
• Surface Water - generated during rainfall events or on site usage of water which can result in contaminated surface waters running off into existing drainage areas. This has the potential to pollute surface water, through the movement of silt and other particulates and may also interfere with existing surface water flow patterns;
• Stormwater– stormwater runoff generated during periods of heavy rainfall or the general use of water on site may result in contamination of stormwater drains; and
• Wastewater – generated through washdown activities of cement areas and vehicles, farm equipment and the use of town water during the fruit packing process to wash products. This may result in contamination of soil, groundwater, stormwater and surface water on site and offsite.
3.2 Objectives
• To ensure there are no adverse impacts upon groundwater resulting from operation of the facility;
• To ensure there are no adverse impacts upon surface water, as a result of operation of the facility; and
• To comply with legislative standards.
3.3 Applicable Legislation, Policies and References The following legislation applies to water management:
• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;
• Water Act 1992; and
• Waste Management and Pollution Control Act 1998.
Relevant policies, codes of practice and measures include:
• National Environmental Protection (Assessment of Site Contamination) Measure 1999.
• Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 78 to 119; and
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 11
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soils Management Sub-plan, Waste Management Sub-plan and Hazardous Products Management Sub-plan are related to this Sub-plan.
3.4 Risk Assessment Table 5: Risk Assessment for Water Management Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Application of irrigation water with high pathogenic content
2 4 8 L
Increasing groundwater levels and potential lateral movement – causing water logging and surface water discharge
3 4 12 M
Changes to the groundwater chemistry 3 4 12 M
Contamination of groundwater from irrigation practice using recycled waters
2 3 6 L
Contamination of groundwater and soils by fertiliser, herbicide and pesticide application
3 2 6 L
Contamination and Alteration of Groundwater
Alteration of hydrogeology and groundwater flows by irrigation operation
3 3 9 L
Surface water contamination due to soil erosion runoff
3 2 6 L
Surface water contamination due to chemical use 3 2 6 L
Contamination of Surface water
Contamination of surface water through fuel or chemical spills
3 2 6 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
12
3.5Ma
nage
men
tAct
ions
–Wat
erEn
viron
men
talC
ontro
lsMi
tigat
ion
and
Mana
gem
ent
Resp
onsib
ility
Reso
urce
sPe
rform
ance
Crite
riaEs
tabl
ish
agr
ound
wat
erm
onito
ring
prog
ram
me
ofex
tract
ion
bore
s.It
isex
pect
edth
atth
epr
opos
edop
erat
iona
lpha
seca
npo
tent
ially
impa
ctsi
gnifi
cant
lyon
exis
ting
grou
ndw
ater
flow
san
dqu
ality
and
isre
quire
dto
bede
sign
edto
both
iden
tify
the
ongo
ing
chan
ges
ingr
ound
wat
erle
vels
and
allo
wre
-est
imat
ion
ofth
epa
laeo
chan
nel
trans
mis
sivi
tyfo
llow
ing
intro
duct
ion
ofth
eSA
Tsc
hem
e
Inst
alll
ocal
ised
drai
nage
bore
sto
inte
rcep
tnea
rsu
rface
late
ralf
low
s
Gro
undw
ater
cont
amin
atio
nm
itiga
tion
Inst
alll
ocal
ised
low
perm
eabi
lity
barr
iers
tobl
ock
near
surfa
cepr
efer
entia
lflo
wpa
thw
ays
DBI
RD
Inst
alla
tion
ofgr
ound
wat
erm
onito
ring
bore
s,dr
aina
gebo
res
and
barr
iers
Rou
tine
mon
itorin
gof
wat
erfro
mex
tract
ion
bore
s
Res
ourc
esto
reco
rdan
dm
anag
ean
alyt
ical
resu
lts
No
adve
rse
impa
cton
grou
ndw
ater
qual
ity
No
sign
ifica
ntch
ange
ingr
ound
wat
erhe
ight
No
sign
ifica
ntsu
rface
late
ral
flow
s
Dur
ing
rain
fall
even
ts,u
nder
take
regu
lar
insp
ectio
nsof
drai
nsan
dne
arby
sens
itive
rece
ivin
gw
ater
sto
ensu
reth
eyar
eno
tbei
ngun
duly
impa
cted
upon
from
sedi
men
tatio
n
Ifex
cess
wat
eris
bein
gus
edon
site
forw
ashi
ngdo
wn
wor
kar
eas
and
vehi
cles
,reg
ular
insp
ectio
nsof
drai
nsan
dne
arby
wat
erco
urse
sne
eds
tobe
unde
rtake
nan
dm
aint
enan
ceun
derta
kew
here
requ
ired
Surfa
cew
ater
/Sto
rmw
ater
cont
amin
atio
nm
itiga
tion
Ifre
quire
d,es
tabl
ish
eros
ion
cont
rolm
easu
res,
i.e.
silt
traps
,ret
entio
nba
sins
,with
inid
entif
ied
runo
ffar
eas
Hor
ticul
tura
list
Reg
ular
insp
ectio
nsof
drai
nage
area
s
Inst
alla
tion
ofer
osio
nco
ntro
lm
easu
res
No
chan
gein
exis
ting
runo
ffpa
ttern
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
13
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Con
tain
allh
azar
dous
subs
tanc
es,f
uels
and
chem
ical
s,in
appr
opria
tear
eas
(i.e.
bund
ing,
cont
ainm
enta
reas
and
cont
rols
truct
ures
)
Surfa
cew
ater
/Sto
rmw
ater
cont
amin
atio
nm
itiga
tion
cont
inue
dEn
gine
erst
orm
wat
erdr
ains
tore
duce
the
velo
city
ofst
orm
wat
eran
den
able
rem
oval
ofco
ntam
inan
tspr
iort
oen
terin
gan
sens
itive
rece
ivin
gw
ater
s
Hor
ticul
tura
list
Mai
nten
ance
ofbu
nded
area
s,co
ntai
nmen
torc
ontro
lst
ruct
ures
Dis
pose
ofw
aste
chem
ical
sto
anau
thor
ised
land
fillw
here
requ
ired
No
inci
denc
esof
fuel
leak
sor
spills
lead
ing
toco
ntam
inat
ion
ofsu
rface
wat
ers
No
was
tepr
oduc
ts,s
uch
asha
zard
ous
orto
xic
subs
tanc
es(fu
els,
chem
ical
s),a
reto
bere
leas
edon
togr
ound
orin
tost
orm
wat
erdr
ain
Und
erta
keau
dits
for
com
plia
nce
Mai
nten
ance
ofbu
nded
area
s,co
ntai
nmen
tor
cont
rol
stru
ctur
esfo
rall
pote
ntia
lge
nera
ted
was
tew
ater
No
untre
ated
was
tew
ater
sar
eto
bere
leas
edon
site
Was
hw
ater
fort
hefru
itpa
ckin
gsy
stem
will
beco
llect
edin
apu
rpos
ebu
iltsu
mp
Was
tew
ater
man
agem
entp
ract
ices
The
fruit
pack
ing
was
hw
ater
colle
cted
inth
esu
mp
will
bete
sted
forq
ualit
y,as
part
ofro
utin
ew
ater
qual
itym
onito
ring,
and
ifsu
itabl
eca
nbe
reus
edon
site
;ifn
otw
illre
quire
disp
osal
thro
ugh
anap
prov
edliq
uid
was
tedi
spos
alco
ntra
ctor
Hor
ticul
tura
list
Prov
ide
purp
ose
built
sum
pfo
rfru
itpa
ckin
gsy
stem
Rou
tine
mon
itorin
gof
sum
pw
ash
wat
er
No
adve
rse
impa
cton
grou
ndw
ater
qual
ity
No
adve
rse
impa
cton
surfa
cew
ater
qual
ity
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 14
4 WASTE MANAGEMENT SUB-PLAN
4.1 Issues and Impacts The solid wastes that may be generated during horticultural operations can be classified as either putrescible or non-putrescible. These include:
• Putrescible materials:
o Organic waste material from fruit packing system;
o Plant prunings, grape waste ( rejected berries and bunches), citrus waste (rejected oranges, rind and pith from juice process), melon waste (rejected melons) and asparagus waste (off-cuts) should these be grown; and
o Paper and cardboard packaging;
• Non-putrescible materials:
o Agrochemical and similar containers;
o Plastics used in the packaging process and also on grape vines to protect grape bunches; and
o Rubble and other materials from general site operations.
The associated impacts from the generation of waste materials include:
• Potential to attract native fauna, such as birds, to the site because of uncovered putrescible materials;
• Increased number of disease carrying organisms such as flies and mosquitoes;
• Potential to cause odours;
• Plastics used to protect grape bunches may be blown about the horticultural site, becoming litter; and
• Stockpiling of non-putrescible material can impact on the visual amenity of the area.
Liquid wastes which can be generated through wash down activities of cement areas and vehicles, earthmoving equipment and other equipment and the use of drinking water in the fruit packing system to wash products has the potential to impact on operations if not managed correctly.
4.2 Objectives
• To minimise the quantity of wastes produced on site;
• To ensure that environmental impacts associated with waste are minimised through appropriate storage, handling and disposal;
• To prevent impacts on the surrounding natural environment and on human health;
• To reduce, reuse and recycle wastes where possible; and
• To ensure all waste that can not be recycled is removed from site and disposed of at an approved waste management facility.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 15
4.3 Applicable Legislation, Policies and References The following legislation applies to waste management:
• Soil Conservation and Land Utilization Act 1980;
• Waste Management and Pollution Control Act 1998;
• Public Health Act 1981;
• Dangerous Goods Act 1981; and
• Environmental Assessment Act 1982.
Relevant policies, codes of practice and measures includes:
• National Environmental Protection (Assessment of Site Contamination) Measure 1999.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soil Management Sub-plan, Water Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan, Weed and Pest Species Management Sub-plan and Air Quality Management Sub-plan are related to this sub-plan.
4.4 Risk Assessment Table 6: Risk Assessment for Waste Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Production of green wastes from pruning and un-saleable produce
4 2 8 L
Production of waste from packing system 4 2 8 L
Use of plastic creating litter problems 3 2 6 L
Production of cardboard and paper waste 4 2 8 L
Generation of solid waste
Production of agrochemical and similar container wastes
3 2 6 L
The generation of minor waste oils from vehicles, operational equipment and pumps
3 2 6 LGeneration of liquid waste
The generation of waste water from produce packing system
3 2 6 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
16
4.5Ma
nage
men
tAct
ions
–Was
teEn
viron
men
talC
ontro
lsMi
tigat
ion
and
Mana
gem
ent
Resp
onsib
ility
Reso
urce
sPe
rform
ance
Crite
riaC
ompo
stgr
een
was
te,p
runi
ngs
and
crop
was
teon
site
and
reus
eto
augm
ents
oils
inth
eho
rticu
lture
plot
s
Prov
ide
area
forc
ompo
stin
gof
gree
nw
aste
Audi
twas
tes
bein
gpl
aced
inco
mpo
stbi
ns
Trai
ning
ofsi
tepe
rson
nel
Prov
ide
putre
scib
lew
aste
bins
fors
tora
geof
dom
estic
was
te(i.
e.fo
od,p
aper
,wra
pper
s)pr
iort
ore
mov
alfro
msi
te
Solid
was
te-
putre
scib
lem
ater
ials
cont
rol
Ifre
quire
d,di
spos
epu
tresc
ible
was
tes
inap
prop
riate
stor
age
bins
and
trans
port
toa
appr
opria
tely
licen
sed
gree
nw
aste
faci
lity
Hor
ticul
tura
list
Adeq
uate
was
tedi
spos
alfa
cilit
ies
onsi
te(c
over
edbi
ns)
Adeq
uate
trans
port
ofw
aste
sof
f-site
toan
appr
oved
licen
sed
land
fillf
acilit
yw
here
requ
ired
Gre
enw
aste
used
onsi
te
Prov
ide
non-
Putre
scib
lew
aste
bins
fors
tora
geof
dom
estic
was
te(i.
e.fo
od,p
aper
,wra
pper
s)pr
iort
ore
mov
alfro
msi
te
Sepa
ratio
nre
cycl
able
was
tes
(pap
eran
dca
rdbo
ard,
othe
rcon
tain
ers)
Prov
ide
adeq
uate
was
tedi
spos
alfa
cilit
ies
(cov
ered
bins
),in
clud
ing
sepa
rate
bins
forr
ecyc
labl
em
ater
ials
Solid
was
tes
-non
-pu
tresc
ible
mat
eria
lsco
ntro
l
Non
-rec
ycla
ble
was
tes
are
tobe
trans
porte
dto
anap
prov
eddi
spos
alfa
cilit
y
Hor
ticul
tura
list
Prov
ide
adeq
uate
trans
port
ofno
n-re
cycl
able
mat
eria
lsof
f-si
te
No
litte
rloc
ated
onsi
te
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
17
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Col
lect
was
hw
ater
from
the
fruit
pack
ing
syst
emin
purp
ose
built
sum
pIn
stal
latio
nof
sum
pfo
rfru
itpa
ckin
gw
ash
wat
erLi
quid
was
teco
ntro
l
The
fruit
pack
ing
was
hw
ater
colle
cted
inth
esu
mp
will
bete
sted
forq
ualit
y,as
part
ofro
utin
ew
ater
qual
itym
onito
ring,
and
ifsu
itabl
e,re
used
onsi
te;i
fno
twill
requ
iredi
spos
alth
roug
han
appr
oved
liqui
dw
aste
disp
osal
cont
ract
or
Hor
ticul
tura
list
Reg
ular
mon
itorin
gof
was
tew
ash
wat
er
Prov
ide
adeq
uate
trans
port
ofw
aste
sof
f-site
byan
appr
oved
was
tedi
spos
alco
ntra
ctor
Liqu
idw
aste
sre
mov
edif
not
suita
ble
forr
euse
onsi
te
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 18
5 HAZARDOUS SUBSTANCES SUB-PLAN
5.1 Issues and Impacts The issues associated with the use of hazardous substances for the operation of the horticulture scheme are:
• Inappropriate use, handling and storage of hazardous products or chemicals that can result in impacts on the surrounding environment, site workers, land users and the surrounding community.
The potential impacts on the environment include:
• Contamination of groundwater and soil;
• Contamination of surface water and groundwater; and
• Impacts on biological aspects of the area.
The potential impacts on site workers, land users and neighbouring properties include:
• Potential injury (long or short term) as a result of incorrect handling and storage procedures; and
• Potential legislative action as a result of incorrect handling and storage procedures.
5.2 Objectives
• To prevent contamination of soil or water through spillage of hazardous substance;
• To manage hazardous material use and disposal in a manner which minimises the risk to the surrounding environment and for the safety of the employees and public; and
• To comply with legislation and regulatory requirements.
5.3 Applicable Legislation, Policies and References The following legislation applies to hazardous substance management:
• Waste Management and Pollution Control Act 1998;
• Dangerous Goods Act 1981;
• Soil Conservation and Land Utilization Act 1980;
• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;
• Water Act 1992; and
• Work Health Act 1986 and Regulations.
Relevant policies, codes of practice and measures include:
• National Environmental Protection (Assessment of Site Contamination) Measure 1999;
• National Code of Practice for the Control of Workplace Hazardous Substances (NOHSC:2007, 1994);
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 19
• Australian Standards for storage, handling and assessment of risks associated with hazardous substances;
• Northern Territory Work Health (Occupational Health And Safety) Regulations (as in force at 26 November 2003) Part 7;
• Storage and handling of hazardous substances in accordance with Northern Territory Work Health (Occupational Health and Safety) Regulations (as in force at 26 November 2003) Part 7; and
• Storage and handling of hazardous substances in accordance with National Code of Practice for the Control of Workplace Hazardous Substances (NOHSC:2007, 1994).
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 120 to 123; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Air Quality Sub-plan and Access and Public Safety Sub-plan are related to this plan.
5.4 Risk Assessment Table 7: Risk Assessment for Hazardous Substance Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Accidental fuel spills associated with operation and storage activities, facilities and wash down of vehicles
3 2 6 LHazardous materials management
Chemical usage/spills of Hazardous Materials such as chemicals, herbicides, pesticides
3 2 6 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
20
5.5Ma
nage
men
tAct
ions
-Haz
ardo
usSu
bsta
nces
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Haz
ardo
usch
emic
als
used
onsi
teto
beha
ndle
dan
dst
ored
inac
cord
ance
with
the
Nat
iona
lCod
eof
Prac
tice
fort
heC
ontro
lofW
orkp
lace
Haz
ardo
usSu
bsta
nces
(NO
HSC
:200
7,19
94)
Det
aile
dha
zard
ous
subs
tanc
esm
anag
emen
tand
stor
age
proc
edur
es
Han
dlin
g,st
orag
ean
ddi
spos
alof
haza
rdou
ssu
bsta
nce
train
ing
fors
itepe
rson
nel
Are
gist
er(s
tock
inve
ntor
y)an
dM
ater
ialS
afet
yD
ata
Shee
ts(M
SDS)
mus
tbe
avai
labl
efo
rall
haza
rdou
ssu
bsta
nces
used
durin
gop
erat
ions
MSD
Sre
cord
san
din
cide
ntre
porti
ng
Dev
elop
anem
erge
ncy
spills
proc
edur
ein
clud
ing
the
repo
rting
alls
pills
and
envi
ronm
enta
linc
iden
tsto
NT
Dep
artm
ento
fInf
rast
ruct
ure,
Plan
ning
and
Envi
ronm
entt
hrou
ghth
eW
aste
Man
agem
ent&
Pollu
tion
Con
trolR
egis
tero
rPol
lutio
nR
espo
nse
Line
1800
064
567
Trai
ning
inus
ean
dst
orag
eof
haza
rdou
ssu
bsta
nce
Haz
ardo
ussu
bsta
nce/
chem
ical
cont
rols
Any
onsi
tem
achi
nery
refu
ellin
gsh
ould
beca
rrie
dou
tin
anap
prov
edar
eaw
here
any
spills
and
leak
sof
haza
rdou
ssu
bsta
nces
can
beco
ntai
ned.
Hor
ticul
tura
list
Und
erta
kere
gula
rau
dit/i
nspe
ctio
nsof
the
site
toen
sure
safe
tym
easu
res
inha
ndlin
gan
dst
orag
eof
haza
rdou
ssu
bsta
nces
are
bein
gim
plem
ente
d
Prov
ide
bund
edar
eas
and
othe
rcon
tain
men
tfac
ilitie
san
dm
aint
ain
No
acci
dent
alsp
illsor
leak
age
ofha
zard
ous
subs
tanc
es
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
21
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Bund
ing
orot
herc
onta
inm
entt
obe
used
for
haza
rdou
ssu
bsta
nces
whe
rere
quire
dH
azar
dous
subs
tanc
e/ch
emic
alco
ntro
ls
cont
inue
dAn
ysp
illsth
atoc
curo
nho
rticu
ltura
llan
dsm
ustb
ere
med
iate
toth
esa
tisfa
ctio
nof
the
regu
lato
ryau
thor
ities
Hor
ticul
tura
list
Inci
dent
man
agem
entr
egis
ter
tobe
impl
emen
ted
for
oper
atio
nala
ctiv
ities
,allo
win
gfo
rfol
low
upac
tions
tobe
deve
lope
d.
No
evid
ence
offu
elor
othe
rch
emic
alre
sidu
efro
mle
akag
eor
spills
onsi
te
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 22
6 VEGETATION, FAUNA AND HABITAT MANAGEMENT SUB-PLAN
6.1 Issues and Impacts There is a potential that horticultural operations could impact on the vegetation and habitats surrounding the site and the native fauna in the area. The potential impacts that may occur on the AZRI site include:
• Loss or alteration of habitat through changes to groundwater flows and height;
• Reduction in the amount of connectivity of bushland between the airport and Todd River;
• Degradation of the adjacent vegetated areas through air-borne dust, changes in hydrology and compaction;
• Disturbance to fauna on site through the creation of artificial fauna attractants, which may result in harm to fauna, or interfere with horticultural operations; and
• Loss of Threatened fauna and flora from the area (either temporarily during site activities or permanently).
6.2 Objectives
• To protect Threatened species or any area of environmental or cultural significance; and
• Limit the impact upon habitat of native species through management practices.
6.3 Applicable Legislation, Policies and References The following legislation applies to vegetation, fauna and habitat management:
• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;
• Territory Parks and Wildlife Conservation Act 2000;
• Weeds Management Act 2001;
• Bushfires Act 2004;
• Plant Diseases Control Act 2000; and
• Soil Conservation and Land Utilization Act 2001.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Weed and Pest Management Sub-plan and Fire Management Sub-plan are related to this Sub-plan.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 23
6.4 Risk Assessment Table 8: Risk Assessment for Vegetation, Fauna and Habitat Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of vegetation 2 2 4 I
Loss of Threatened flora or fauna species 2 4 8 L
Disturbance to fauna 3 3 6 L
Impact to vegetation, fauna and habitat
Loss of habitat 2 2 4 I
Horti
cultu
reOp
erat
iona
lEnv
ironm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
24
6.5Ma
nage
men
tAct
ion
-Veg
etat
ion,
Faun
aand
Habi
tat
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Min
imis
ear
eas
clea
red
durin
gop
erat
ions
and
ensu
reop
erat
iona
lact
iviti
esar
ew
ithin
boun
dary
ofho
rticu
ltura
lsite
and
note
xten
ding
toar
eas
ofna
tive
vege
tatio
nsu
rrou
ndin
gsi
te
Con
fine
horti
cultu
ralv
ehic
lem
ovem
entt
obo
unda
ries
ofho
rticu
ltura
lsite
tom
inim
ise
the
pote
ntia
lim
pact
onna
tive
flora
Trai
ning
ofpe
rson
nel
Mon
itort
heef
fect
sof
repe
ated
vehi
cle
use
insu
scep
tible
area
sto
ensu
reno
sign
ifica
ntso
ilan
dve
geta
tion
loss
isoc
curr
ing
Avoi
dsp
rayi
nghe
rbic
ides
durin
gst
rong
win
dsto
prev
enti
mpa
cts
onne
ighb
ourin
gve
geta
tion
Visu
alin
spec
tion
ofbo
unda
ryve
geta
tion
and
rem
nant
bush
land
with
insi
te
No
off-s
iteim
pact
sto
vege
tatio
nor
habi
tat
Nat
ive
flora
man
agem
ent
Con
tinue
enha
ncem
ento
fbuf
ferv
eget
atio
n
Hor
ticul
tura
list
Pers
onne
lto
unde
rtake
wee
dco
ntro
land
/orp
lant
ing
ofbu
ffera
reas
Incr
ease
inde
nsity
ofbu
ffer
vege
tatio
n
Nat
ive
faun
am
anag
emen
tM
aint
ain
acl
ean
and
tidy
wor
kar
eato
ensu
reth
atna
tive
faun
aar
eno
tattr
acte
dto
the
site
Hor
ticul
tura
list
Prov
ide
cove
red
bins
Fenc
em
aint
enan
ce
No
prob
lem
sw
ithna
tive
faun
asp
ecie
ssc
aven
ging
Horticulture Operational Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 25
7 WEEDS AND PEST SPECIES MANAGEMENT SUB-PLAN
7.1 Issues and Impacts The introduction of weeds and pest species during the operational phase may cause environmental impacts to the project site. Weeds may be introduced from operational activities including the movement of vehicles across site, use of mulch and bringing in topsoil. Weeds have the potential to:
• Increase the risk of wildfire;
• Compete with native plants and horticultural crops;
• Change the micro-habitat;
• Encourage an excessive use of herbicide use in weed control; and
• Affect visual amenity.
The potential issues from pest species during operational activities include:
• Increase in feral animal activities on site (including wandering domestic pets, rabbits, feral cats and the house mouse). This has the potential to interfere with horticultural activities. Feral animals can also impact on native flora in the area as well as create unnecessary risks to site operations;
• Potential to attract to the AZRI site problem wildlife that may pose a threat to existing and potential operations and encourage predation on native wildlife; and
• Attraction of flying insects, including mosquitoes, to the site, as the result of unseasonal presence of surface water bodies which can be used for breeding sites. This is an issue because the proposed operations are adjacent to neighbouring residential properties.
Pest species have the potential to adversely affect native fauna through competition for food and nesting or roosting areas, through predation and by adversely affecting fauna habitat though soil disturbance and changing vegetation composition. Pest species may also create health and nuisance risks to adjacent landholders.
7.2 Objectives
• To prevent the introduction of new weed species on the site;
• To prevent the spread of existing weed species on the site;
• To prevent the creation of habitat suitable for pest species; and
• To minimise the occurrence of feral animals visiting or residing in the site.
7.3 Applicable Legislation, Policies and References The following legislation applies to weed and pest species management:
• Commonwealth Environment Protection and Biodiversity Conservation Act 1999;
• Territory Parks and Wildlife Conservation Act 2000;
• Weeds Management Act 2001;
Horticulture Operational Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 26
• Bushfires Act 2004;
• Plant Diseases Control Act 2000; and
• Soil Conservation and Land Utilization Act 2001.
Relevant policies, codes of practice and measures include:
• Article 20 of the World Health Organisation Regulation; and
• NT Medical Entomology Branch Guidelines.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soils Management Sub-plan, Water Management Sub-plan, Waste Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan, Fire Management Sub-plan are related to this Sub-plan.
7.4 Risk Assessment Table 9: Risk Assessment for Weeds and Pest Species
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Weed establishment from vegetation clearing and soil disturbance
4 2 8 L
Introduction of weed species from introduction of off-site soil and mulch
4 2 8 L
Weed establishment or spread
Introduction of weed species from vehicles travelling across site
4 2 8 L
Increased mosquito breeding as result of artificial ponding
3 3 9 LPest species
Loss of native invertebrates due to non-selective mosquito fogging
3 3 9 L
Introduction of feral species
Feral species (including domestic dogs) interfering with site operations
2 2 4 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
27
7.5Ma
nage
men
tAct
ions
-Wee
dsan
dPe
stSp
ecies
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Mon
itorw
eeds
aspa
rtof
the
annu
alsi
tem
aint
enan
cepr
ogra
mm
e
Und
erta
kem
echa
nica
l,ph
ysic
alor
chem
ical
cont
rol
ofw
eeds
acro
ssho
rticu
ltura
lsite
,as
requ
ired
Buffe
lgra
sssh
ould
notb
ere
mov
edin
the
abse
nce
ofan
othe
rsui
tabl
egr
ound
cove
rto
mai
ntai
nso
ilst
abilit
y
No
incr
ease
inar
eas
ofw
eed
infe
stat
ion
Tops
oils
tripp
edfro
mw
eed-
infe
sted
area
sm
aybe
lade
nw
ithw
eed
seed
san
dm
ustb
ere
mov
edfro
msi
teor
treat
edto
prev
enti
ntro
duci
ngw
eeds
into
curr
ently
wee
dfre
ear
eas
Wee
dco
ntro
l
Whe
nw
orki
ngin
wee
din
fest
edar
eas,
ensu
reve
hicl
esan
deq
uipm
enta
recl
eane
dpr
iort
om
ovin
gto
wee
dfre
ear
eas
Hor
ticul
tura
list
Reg
ular
audi
t/in
spec
tion
ofth
esi
teto
ensu
rew
eed
man
agem
entm
easu
res
are
bein
gim
plem
ente
d
No
intro
duct
ion
ofne
ww
eed
spec
ies
Esta
blis
han
dm
aint
ain
are
gist
erto
reco
rdsi
ghtin
gsof
fera
lani
mal
sFe
rala
nim
alm
anag
emen
t
No
dom
estic
anim
als
tobe
brou
ghto
nto
the
site
Hor
ticul
tura
list
Rab
bitp
roof
fenc
e
Insp
ectio
nof
the
site
toen
sure
fera
lani
mal
sha
veno
ttak
enup
resi
denc
eon
site
Ifin
crea
sein
popu
latio
nof
fera
lani
mal
s–
unde
rtake
aner
adic
atio
npr
ogra
mm
e
No
sign
ifica
ntin
crea
sein
fera
lan
imal
son
horti
cultu
rals
ite
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
28
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Use
bird
frigh
toro
ther
met
hods
,suc
has
netti
ng,t
opr
even
tacc
ess
ofpe
stbi
rdsp
ecie
sto
horti
cultu
ral
crop
s(e
spec
ially
grap
esan
dci
trus)
Inve
stig
atio
nof
avai
labl
em
etho
dsfo
rdet
errin
gbi
rds
onho
rticu
ltura
lcro
ps
Inve
stig
ate
use
offlo
atin
gco
verf
orre
cycl
edw
ater
hold
ing
area
,to
prev
ente
ncou
rage
men
tofp
est
spec
ies
tow
ater
Mai
ntai
na
clea
nan
dtid
yw
ork
area
toen
sure
scav
enge
rspe
cies
are
nota
ttrac
ted
toth
esi
tePr
ovid
etra
inin
gto
pers
onne
l
Ensu
repu
tresc
ible
bins
are
cove
red
Prov
ide
cove
red
bins
Min
imal
occu
rren
ceof
pest
spec
ies
onsi
te
Ensu
rere
cycl
edw
ater
hold
ing
area
isfre
eof
vege
tatio
nan
dst
eep-
side
d,to
prev
entt
hecr
eatio
nof
area
san
dst
ruct
ures
inw
hich
mos
quito
esca
nbr
eed
Reg
ular
mai
nten
ance
ofst
orag
ear
eaH
oldi
ngar
eano
tveg
etat
ed
Use
ambe
rorc
oolw
hite
exte
rnal
light
son
infra
stru
ctur
eto
min
imis
eat
tract
ing
pest
spec
ies
Pest
spec
ies
man
agem
ent
Und
erta
kem
osqu
itom
onito
ring
atre
gula
rint
erva
lsdu
ring
the
year
.Ad
vice
shou
ldbe
soug
htfro
mth
eD
epar
tmen
tofH
ealth
and
Com
mun
itySe
rvic
es(D
HC
S)to
dete
rmin
eth
etim
ing
ofm
onito
ring
from
year
toye
aran
dsp
ecie
slik
ely
tobe
enco
unte
red
Hor
ticul
tura
list
Poss
ible
treat
men
tofp
onde
dsu
rface
wat
ers
Baite
dm
osqu
itotra
ps
Liai
son
with
DH
CS
No
incr
ease
inm
osqu
itoab
unda
nce,
asde
term
ined
thro
ugh
mon
itorin
gan
d/or
com
mun
ityco
mpl
aint
s
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 29
8 FIRE MANAGEMENT SUB-PLAN
8.1 Issues and Impacts Currently the AZRI site has a well-maintained network of firebreaks and access tracks (minimum 4 m wide) located around the perimeter. The potential impacts of uncontrolled fire for the horticultural operations include:
• Creation of weed corridors;
• Disruption of the current fire management regime;
• Loss of existing vegetation and fauna habitat;
• Disruption of the operational activities; and
• Potential for injury to horticultural workers or other community members.
8.2 Objectives
• To prevent uncontrolled wildfire on the site;
• To ensure safety of site personnel, surrounding residential areas; and
• To protect native vegetation from the impact of hot wildfires.
8.3 Applicable Legislation, Policies and References The following legislation applies to fire management:
• Commonwealth Environment Protection and Biodiversity Conservation Act 1999; and
• Bushfires Act 2004.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 124 to 137; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Vegetation, Fauna and Habitat Management Sub-plan and Weed and Pest Species Management Sub-plan are related to this Sub-plan.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 30
8.4 Risk Assessment Table 10: Risk Assessment for Fire Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Loss of horticulture infrastructure and assets 3 4 12 M
Weed establishment after fire disturbance 3 3 9 L
Fire
Loss of existing vegetation and fauna habitat 2 3 8 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
31
8.5Ma
nage
men
tAct
ions
–Fire
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Con
tinue
with
the
curr
entp
olic
yof
fire
prev
entio
nus
edon
AZR
Iwhi
chin
clud
esco
ordi
natin
gw
ithth
evo
lunt
eera
ndre
gula
rfire
-figh
ters
Upd
ate
curr
entf
irepr
even
tion
polic
yfo
rnew
activ
ities
unde
rtake
non
horti
cultu
resi
te
Con
tinue
mai
nten
ance
offir
ebr
eaks
arou
ndAZ
RI
site
DBI
RD
Mai
nten
ance
offir
ebre
aks
onan
nual
basi
s
Prev
entt
heus
eof
open
fires
Mai
ntai
nne
wly
esta
blis
hed
inte
rnal
fireb
reak
son
the
horti
cultu
rals
iteFi
rem
anag
emen
tpla
nan
dco
nsul
tatio
nw
ithD
BIR
D
Alls
itepe
rson
nela
reto
bein
duct
edin
tofir
eris
k,pr
even
tion
and
man
agem
ent
Fire
man
agem
ent
Hav
efir
efig
htin
geq
uipm
enti
nst
rate
gic
loca
tions
acro
sssi
tean
din
vehi
cles
Con
tract
or
Hor
ticul
tura
list
Indu
ctio
nan
dtra
inin
gof
site
pers
onne
l
No
incr
ease
inin
cide
nce
ofw
ildfir
e
Wild
fires
noto
rigin
atin
gfro
mAZ
RIs
ite
Fire
brea
ksm
aint
aine
d
Pers
onne
law
are
offir
em
anag
emen
ttec
hniq
ues
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 32
9 HERITAGE MANAGEMENT SUB-PLAN
9.1 Issues and Impacts The area designated for horticultural operations has no archaeological or heritage sites. However, a survey conducted of the AZRI site (Crassweller, 2004) located 10 artefact scatters along creek and drainage lines and on the flat plains. The potential impacts associated with the site activities on cultural and heritage values in the area include:
• The possibility that identified sites of significance could be disturbed inadvertently if workforce members moved outside the operational area;
• Loss of or disturbance to significant trees retained during clearing operations in the construction phase; and
• Disturbance to significant land forms.
9.2 Objectives
• To minimise the impact on cultural sites, values and artefacts during horticultural activities;
• To manage any newly discovered heritage objects appropriately; and
• To minimise damage to significant trees retained, landscapes or artefacts.
9.3 Applicable Legislation, Policies and References The following legislation applies to heritage management:
• Aboriginal and Torres Strait Islander Heritage Protection Act 1984;
• Northern Territory Aboriginal Sacred Sites Act 2004;
• Aboriginal Land Act 2004;
• Heritage Conservation Act 2000; and
• National Trust (Northern Territory) Act 2001.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 138 to 140; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 33
9.4 Risk Assessment Table 11: Risk Assessment for Heritage Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Disturbance of Indigenous Heritage values 2 2 4 I
Disturbance of European Cultural Heritage values 2 2 4 I
Loss of or disturbance to significant trees retained 4 4 12 M
Loss of heritage and cultural values
Disturbance to significant landforms 3 3 9 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
34
9.5Ma
nage
men
tAct
ions
–Her
itage
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Ifin
dige
nous
arte
fact
sar
efo
und
durin
gho
rticu
lture
oper
atio
ns,t
heop
erat
ion
will
ceas
ean
dSi
teM
anag
emen
tand
DBI
RD
proj
ectm
anag
erw
illbe
notif
ied
imm
edia
tely
Com
mun
icat
ion
with
AAPA
,O
ffice
ofEn
viro
nmen
t&H
erita
gean
dla
ndcu
stod
ians
Con
fine
horti
cultu
reve
hicl
esto
desi
gnat
edtra
cks
and
acce
ssw
ays
tom
inim
ise
the
pote
ntia
lto
impa
cton
sign
ifica
nttre
esre
tain
ed
No
vehi
cles
park
edin
vege
tate
dar
eas
Mak
em
apor
plan
ofar
eas
ofcu
ltura
land
herit
age
sign
ifica
nce
avai
labl
efo
rins
pect
ion
byw
ork
forc
e
Und
erta
kecu
ltura
law
aren
ess
train
ing
ofth
ew
orkf
orce
Her
itage
man
agem
ent
No
wor
kis
tobe
cond
ucte
dou
tsid
eof
desi
gnat
edho
rticu
ltura
lare
a
Hor
ticul
tura
list
Prov
ide
cultu
rala
war
enes
stra
inin
gto
site
pers
onne
lN
oar
tefa
cts
orsi
gnifi
cant
site
sar
edi
stur
bed
orda
mag
edw
ithou
tprio
rapp
rova
l
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 35
10 AIR QUALITY MANAGEMENT SUB-PLAN
10.1 Issues and Impacts Air quality issues can occur as the result of horticultural operations. These issues include:
• Dust creation from vehicles travelling across site and during farming activities (harvesting and planting);
• Odours from pre-storage of recycled water prior to use in irrigation;
• Odours, from the recycled water being used to irrigate horticultural areas; and
• Spraydrift from agrochemicals such as herbicides, fungicides, insecticides, growth regulators and fertilisers.
The impacts associated with these issues include:
• Production of nuisance dust emissions which can potentially cause:
o Airborne dust to settle on employee vehicles;
o Dust generated from the site activities can create health (respiratory) issues for workers and adjoining site users (including neighbouring residential area);
o Dust settling on the local drainage channels increasing turbidity and reducing the transfer of oxygen between air and water;
• Odours diminishing the quality of life for surrounding residents; and
• Spraydrift which can potentially impact on the neighbouring residents by:
o Affecting non-target crops, pastures, gardens and surrounding vegetation; and
o Affecting human and livestock health.
10.2 Objectives
• To manage air emissions from the horticultural operations, particularly nuisance dust, odour and spraydrift of agrochemicals;
• To comply with air quality standards, regulations and guidelines as defined by Commonwealth and Northern Territory legislation; and
• To minimise greenhouse gas emissions.
10.3 Applicable Legislation, Policies and References The following legislation applies to air quality management:
• Ozone Protection Act 1990;
• Dangerous Goods Act 1981;
• Waste Management and Pollution Control Act 1998; and
• Work Health Act 1986.
Relevant policies, codes of practice and measures include:
• National Health and Medical Research Council (NHMRC) Guidelines for Air Quality;
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 36
• National Exposure Standards for Atmospheric Contaminants in the Occupational Environment (NOHSC, 1003);
• Air Quality Standards AS/NZS 3580.10.1:2003 - Methods for sampling and analysis of ambient air;
• Australian Standard AS2985-2004 workplace atmospheres-method for sampling and gravimetric determination of respirable dust;
• Australian Ventilation Standard AS 1666.2; and
• Occupational Health and Safety Regulations and advisory standards.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Soil Management Sub-plan, Hazardous Substance Management Sub-plan, Vegetation, Fauna and Habitat Management Sub-plan and Access and Public Safety Management Sub-plan are related to this Sub-plan.
10.4 Risk Assessment Table 12: Risk Assessment for Air Quality Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Nuisance dust impacting on nearby residences 5 3 15 H
Nuisance dust impacting on site workers 5 3 15 H
Impact from nuisance dust on adjacent vegetated areas
3 2 6 L
Dust
Increasing turbidity and reducing the transfer of oxygen between air and water from dust settling on the local drainage channels
2 2 4 I
Odour Impact on the aesthetics of the surrounding area 2 2 4 I
Spraydrift Spraydrift impacting on neighbouring residents 4 2 8 L
Greenhouse gases
Production of greenhouse gas emissions 5 1 5 I
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
37
10.5
Mana
gem
entA
ctio
ns-A
irQu
ality
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Res
trict
mov
emen
ton
boun
dary
fireb
reak
sto
that
requ
ired
forA
ZRIp
rope
rtym
anag
emen
tR
egul
arro
adan
dtra
ckm
aint
enan
ce
Hig
hus
ero
ads
shou
ldbe
cons
truct
edto
min
imis
edu
stge
nera
tion
Mai
nten
ance
ofac
cess
road
s
Am
axim
umsp
eed
limit
of20
km/h
will
beim
pose
dw
ithin
the
site
toco
ntro
lgen
erat
ion
ofdu
stby
vehi
cles
mov
ing
thro
ugh
oper
atio
nar
eas
Mee
tsth
eN
HM
RC
Gui
delin
esfo
rAir
Qua
lity
Dai
lyas
sess
men
tofw
eath
erco
nditi
ons
Reg
iste
rofd
aily
win
dco
nditi
ons
Dur
ing
perio
dsof
high
win
dsw
hen
soil
moi
stur
eis
low
,add
ition
alpr
ecau
tions
will
need
tobe
unde
rtake
nto
prot
ecte
xpos
edsu
rface
s.Th
ese
may
incl
ude
incr
ease
dfre
quen
cyof
wat
erin
gan
dce
ssat
ion
ofsi
teop
erat
ions
durin
gst
rong
win
dsw
hich
are
likel
yto
mob
ilise
soils
and
dust
,es
peci
ally
ifw
inds
are
blow
ing
tow
ards
sens
itive
rece
ivin
gar
eas
(e.g
.res
iden
tiala
rea)
Ensu
real
lexp
osed
soils
are
stab
ilised
e.g.
usin
gm
ulch
toas
sist
with
dust
supp
ress
ion
Mul
chin
gm
achi
ne
Dus
tgen
erat
ing
activ
ities
ceas
edor
supp
ress
ion
mea
sure
sim
plem
ente
dw
hen
stro
ngw
inds
pres
ent
Enha
nce
the
buffe
rzon
esth
atha
vepo
orve
geta
tion
cove
rPe
rson
nelt
oun
derta
kew
orks
Man
agem
ento
fnu
isan
cedu
stem
issi
ons
Rec
ord
any
dust
com
plai
nts
Hor
ticul
tura
list
Mai
ntai
na
dust
com
plai
nts
regi
ster
No
dust
com
plai
nts
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
38
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Use
sub-
surfa
cedr
ippe
rsan
dco
vere
dre
cycl
edw
ater
stor
age
area
sto
min
imis
eex
posu
reof
recy
cled
wat
erto
air
Mai
ntai
na
min
imum
50m
buffe
rdis
tanc
efro
mre
side
ntia
lare
asar
ound
alls
ourc
esof
recy
cled
wat
er
Enha
nce
buffe
rare
asth
atha
vepo
orve
geta
tion
cove
rPe
rson
nelt
oun
derta
kew
orks
Odo
urm
anag
emen
t
Rec
ord
any
odou
rcom
plai
nts
Hor
ticul
tura
list
Mai
ntai
nan
odou
rcom
plai
nts
regi
ster
No
odou
rcom
plai
nts
Mai
ntai
na
50m
buffe
rdis
tanc
ebe
twee
nop
erat
ions
and
neig
hbou
ring
resi
dent
iala
reas
and
enha
nce
buffe
rare
asth
atha
vepo
orve
geta
tion
cove
r
Pers
onne
lto
unde
rtake
wor
ks
Onl
yus
eag
roch
emic
als
inac
cord
ance
with
labe
lling
and
licen
sing
Keep
MSD
San
dre
gist
erof
chem
ical
use
Use
only
agro
chem
ical
slic
ense
dfo
ruse
onra
wpr
oduc
ean
dcr
ops
grow
n
Min
imis
eth
eus
eof
pest
icid
esan
dhe
rbic
ides
toth
atne
cess
ary
fore
ffici
ento
pera
tions
and
mai
ntai
nre
cord
sof
thei
ruse
Ensu
real
lequ
ipm
enti
sm
aint
aine
dan
dca
libra
ted
appr
opria
tely
and
thei
ruse
follo
wal
loth
erac
cept
edin
dust
rypr
actic
es
Spra
ydrif
tcon
trol
Ensu
real
lope
rato
rsar
etra
ined
appr
opria
tely
inch
emic
als
use
Hor
ticul
tura
list
Trai
ning
ofsi
tepe
rson
neli
nth
eus
e,st
orag
ean
dm
aint
enan
ceof
agro
chem
ical
s
No
spra
ydrif
tcom
plai
nts
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
39
Envir
onm
enta
lCon
trols
Mitig
atio
nan
dMa
nage
men
tRe
spon
sibilit
yRe
sour
ces
Perfo
rman
ceCr
iteria
Asse
ssan
dre
cord
clim
atic
cond
ition
son
nom
inat
edda
yof
use
–if
win
ddi
rect
ion
isbl
owin
gto
war
dsse
nsiti
vere
ceiv
ing
area
oper
atio
nsw
illce
ase
until
win
ddi
rect
ion
chan
ges
Mai
ntai
nre
cord
sof
wea
ther
cond
ition
sSp
rayd
riftc
ontro
l
cont
inue
d
Reg
iste
rofs
pray
drift
com
plai
nts
Hor
ticul
tura
list
Mai
ntai
na
spra
ydrif
tco
mpl
aint
sre
gist
er
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 40
11 NOISE MANAGEMENT SUB-PLAN
11.1 Issues and Impacts The primary source of noise from horticultural operations may include tractors, vehicles, chemical spraying equipment, water pumps and the use of gas guns for bird deterrent.
The use of high-volume sprayers to fertilise and apply fungicide can generate a large amount of noise; however, the necessity of this is restricted to times in January, September, October and November for table grape crops.
The use of gas guns to deter birds away from crops is expected in September, October and November. This source of noise can potentially have a significant impact on neighbouring residences because of its use in the early morning and the loudness of the gas guns.
The impact of noise on nearby residences will be largely dependent on time of day noise is created. Activities such as tractors and spraying equipment at night will be noticed more than if used during the day.
11.2 Objectives
• To minimise noise emissions due to site operations on the adjacent residential areas and other potential receivers;
• To ensure activities are conducted without the use of excessive noise; and
• To comply with relevant noise standards.
• To ensure a noise complaints register is maintained and remedial actions recorded; and
• To comply with relevant legislation and regulations.
11.3 Applicable Legislation, Policies and References The following legislation applies to noise management:
• Waste Management and Pollution Control Act 1998; and
• Work Health Act 1986.
Relevant policies, codes of practice and measures include:
• Draft Waste Management and Pollution Control (Environmental Noise) Regulations;
• Occupational Noise National Code of Practice; and
• Occupational Health and Safety Regulations and advisory standards.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Access and Public Safety Management Sub-plan is related to this Sub-plan.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 41
11.4 Risk Assessment Table 13: Risk Assessment for Noise Issues
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Noise from site activities impacting on neighbouring residences resulting in noise complaints
5 3 15 HNoise
Impaired hearing of site personnel as the result of using noisy equipment
3 4 12 M
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
ater
Reus
eSch
eme
HLA
Ref:B
6002
70_R
PT_F
inal_H
ortO
EMP_
11Ap
r05
42
11.5
Mana
gem
entA
ctio
ns–N
oise
Envir
onm
enta
lCo
ntro
lsMi
tigat
ion
and
Mana
gem
ent
Resp
onsib
ility
Reso
urce
sPe
rform
ance
Crite
ria
Mai
ntai
nm
inim
um50
mbu
fferd
ista
nce
from
resi
dent
iala
rea
and
enha
nce
buffe
rar
eas
that
have
poor
vege
tatio
nco
ver
Enha
ncem
ento
fbuf
ferz
ones
Whe
repo
ssib
le,o
pera
tem
achi
nery
and
othe
rveh
icle
s,aw
ayfro
mth
ere
side
ntia
lar
ea(w
este
rnsi
deof
site
),be
twee
nth
eho
urs
of19
00an
d07
00
Mac
hine
ryus
edat
the
site
shou
ldbe
wel
lm
aint
aine
dw
ithhi
ghef
ficie
ncy
muf
flers
fitte
dto
alls
iteeq
uipm
ents
oth
atth
eyco
nfor
mto
the
Nat
iona
lSta
ndar
dfo
rO
ccup
atio
nalN
oise
(NO
HSC
:100
7(2
000)
.
Prov
ide
engi
neer
ing
mea
sure
sto
limit
impa
cton
wor
kfor
ceus
ing
nois
yeq
uipm
ento
rpro
vide
Pers
onal
Prot
ectiv
eEq
uipm
entw
hils
tope
ratin
gor
wor
king
near
earth
mov
ing
equi
pmen
toro
ther
mac
hine
ryw
here
requ
ired
inac
cord
ance
with
natio
nals
tand
ards
Mai
nten
ance
ofm
achi
nery
PPE
Adve
rtise
inte
nded
use
ofbi
rdfri
ght(
gas
guns
)as
perc
urre
ntpr
actic
e
Hor
ticul
tura
list
Adve
rtise
men
tin
loca
lpap
er
Inve
stig
ate
alte
rnat
ive
met
hods
ofbi
rdde
terr
ent
Inve
stig
atio
nof
avai
labl
em
etho
dsfo
rdet
errin
gbi
rds
onho
rticu
ltura
lcro
ps
Plan
tand
Equi
pmen
tNoi
se
Reg
iste
rofn
oise
com
plai
nts
Hor
ticul
tura
list
DBI
RD
Mai
nten
ance
ofa
nois
eco
mpl
aint
sre
gist
er
No
nois
eco
mpl
aint
s
Mee
tsO
ccup
atio
nal
Noi
seN
atio
nalC
ode
ofPr
actic
e
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 43
12 ACCESS AND PUBLIC SAFETY MANAGEMENT SUB-PLAN
12.1 Issues and Impacts There is a risk that visitors (authorised and unauthorised) may access the construction site. This can potentially create liabilities for the horticultural management. The potential impacts associated with horticultural activities include:
• Insecure areas may result in members of the public harming themselves;
• Insecure areas may result in operational equipment being damaged; and
• Inappropriate site access points can create traffic problems and increase the risk of accidents occurring and complaints being made.
12.2 Objectives
• To minimise the impacts of horticultural activities on existing roads;
• To minimise the risk of injury to other road users and members of the public traversing Colonel Rose Drive;
• To minimise impacts on site visitors (authorised and unauthorised), local residents, tourists and commuters;
• To prevent unauthorised access of people; and
• To prevent injury to site visitors.
12.3 Applicable Legislation, Policies and References The following legislation applies to access and public safety management:
• Dangerous Goods Act 1981;
• Public Health Act 1981; and
• Work Health Act 1986.
Relevant reports and documents include:
• Public Environment Report, Alice Springs Water Reuse Scheme, pages 141 to 155; and
• Horticulture Construction Environmental Management Plan, Alice Springs Water Reuse Scheme.
The Noise Management Sub-plan and Air Quality Sub-plan are related to this Sub-plan.
Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 44
12.4 Risk Assessment Table 14: Risk Assessment for Access and Public Safety
Issue Priority
Environmental Issue Potential Environmental Incidents
Likelihood
Consequence
Total
Priority
Vehicle accidents as the result of inappropriate site access points for entering and exiting site
3 3 9 L
Visitors (authorised and unauthorised) on site harming themselves
3 3 9 L
Site Access
Visitors (authorised and unauthorised) on site causing damage to operational equipment
3 3 9 L
Horti
cultu
reOp
erat
ion
Envir
onm
enta
lMan
agem
entP
lan,A
liceS
prin
gsW
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Horticulture Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 46
13 INDUCTION TRAINING REQUIREMENTS The purpose of induction training is to ensure that all personnel who are engaged in the operation of the horticulture venture are aware of their environmental obligations. The horticulturalist and site environmental officer will be responsible for the conduct of environmental induction training for all persons working on site, including any subcontractors.
An experienced and qualified environmental trainer is to undertake environmental induction training for all personnel involved in the construction of the horticultural site. It is proposed that the environmental induction training for site personnel and sub-contractors can be undertaken at two levels:
1. Complete induction - training for personnel who will be on site for more than five days or those personnel on site for less than five days but involved in activities that have the potential to cause environmental harm (e.g. installation and maintenance of erosion and sediment control devices, clearing and grubbing, felling of trees, earthworks, stabilising disturbed surfaces).
2. Quick induction - training for personnel that will be on site for less than five days and are undertaking activities that do not have the potential to cause significant environmental harm.
An induction training programme for both induction levels needs to be developed. The induction training for both levels should cover the same issues. The difference between the two induction courses is the level of training provided for each issue. The issues to be addressed in induction include (but are not limited) to the following:
• Awareness of the Horticulture OEMP;
• Awareness of general environmental duties under the relevant Acts and the consequences of any breaches;
• An overview of what constitutes an environmental incident and the appropriate person to notify in the event of an environmental incident;
• General awareness of the environmental and cultural significance of the adjacent local drainage channels, vegetation corridors and buffer area;
• Location of No Go areas, particularly St Mary’s Creek, the buffer area and recognised cultural areas;
• Specific practices required for erosion and sediment control;
• General flora and fauna management;
• Speed limit restrictions throughout the site;
• Procedures to follow and who to contact in the case of a hydrocarbon or other hazardous substance spill;
• The location and use of fire extinguishers/hydrants;
• Appropriate waste management practices;
• Awareness and understanding of non-drinking water signage; and
• The appropriate person to notify in the event that any environmental mishaps occur.
The environmental induction training can be undertaken alongside the OH&S training.
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 47
14 MONITORING FRAMEWORK Monitoring is the systematic collection of data and information in relation to specific environmental issues or conditions. The main purposes of monitoring are:
• To identify trends and changes over time and between areas to enable identification of measures to improve environmental practices and performance; and
• To assist in the identification of non-predicted impacts.
There are two main areas that can be monitored, environmental condition and environmental management.
14.1 Environmental Condition Monitoring of environmental condition will establish whether the recommended practices in this EMP are effective in achieving their desired environmental outcome and will allow for the detection of non-predicted impacts. The principle issues requiring monitoring during the horticultural operations relate to:
• Changes to groundwater level and chemistry;
o Increasing groundwater levels and potential lateral movement – causing water logging and surface water discharge;
o Contamination of groundwater and soils by fertiliser, herbicide and pesticide application;
o Groundwater flow and quality within alluvial sediments outside the immediate horticultural site; and
o Increased migration of existing saline groundwater present in alluvial sediments through poorly constructed or old bores used to extract groundwater from underlying Tertiary sediments within the AZRI site and adjacent rural residential properties;
• Change to soil properties;
• Quality and quantity of recycled water recovered from extraction wells;
• Change to vegetation structure and fauna habitats;
• Complaints received from neighbouring properties from nuisance dust, excessive noise, spray drift and odours caused from horticultural operations; and
• Increase in the number of mosquitoes/biting insects.
14.1.1 Groundwater Monitoring
Monitoring of groundwater, commenced during the construction phase, should be continued during the operational phase. The groundwater monitoring programme will be crucial to assessing and effectively managing each component of the water reuse scheme within the AZRI site. The monitoring programme will require sampling and analysis of the extraction bores and the existing Tertiary extraction wells located within the AZRI site and a representative selection of six extraction wells within the adjacent rural residential properties.
A sampling and analysis programme will be established prior to the commencement of irrigation activities to measure the ambient groundwater concentrations. The sampling and analysis
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 48
programme will be undertaken for a suite of contaminants including major ions, metals and nutrients (Table 15).
Table 15: Groundwater Monitoring during Horticulture Operations
Parameter Suggested Determinants Frequency of testing per year
Site(s)
Heavy Metals Al, As, B, Cu, Cd, Cr, Zn (as minimum suite)
2 Monitoring bores
Dominant ions Ca, Na, K, Cl, SO4, HCO3. 4 Infiltration ponds and monitoring bores
TDS Conductance (25°C). Calculation based on above.
12 Infiltration ponds and monitoring bores
Organics Pesticides, MBAS, TOC and DOC
1 Infiltration ponds and monitoring bores
Field determinations pH, turbidity, temperature, dissolved oxygen, ORP
12 Infiltration ponds and monitoring bores
Oxygen demand BOD, COD 12 Infiltration ponds and monitoring bores
Bacteriological indicators
Coliforms and E. coli 12 Infiltration ponds and monitoring bores
Pathogen indicators C. perfringens, viruses 2 Infiltration ponds and monitoring bores
Nutrients Total and dissolved P, Total N, TKN, NOx
2 Infiltration ponds and monitoring bores
14.1.2 Monitoring of Recycled Irrigation Water from Extraction Bores The recycled water coming from the extraction bores will be monitored for quality and quantity:
• Water Quality Monitoring, continuous or routine analysis of waste water:
o TDS - salinity levels in irrigation water;
o EC;
o pH;
o Nutrients - P and N;
o Biological Oxygen Demand (BOD);
o Heavy metals;
o Thermo-tolerant Coliforms; and
o Chlorine residue; and
• Water Quantity Monitoring:
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 49
o Volume of recycled water in SAT basins to guarantee supply of irrigation water;
o Volume of recycled water extracted for irrigation or storage; and
o Volume of recycled water used for irrigation.
14.1.3 Soil Testing Testing of the soil for horticultural operations will require samples to be collected from within the irrigation wetting zone. It is recommended that the sample density for the site will be one sample per 5 ha. The primary sample will combine 20 sub-samples from each 5 ha from each of the four depths indicated in Table 16. Analysis will be undertaken on the combined primary sample from each depth (total of four samples sent to a laboratory from each 5 ha).
A sampling and analysis programme will be undertaken of soils from the irrigation zone for nutrients, pH, EC, CEC and SAR. ESP will be calculated from the results of laboratory tests (Table 16).
Table 16: Soil Testing in Irrigation Area
Parameter Units Depth Frequency of testing / year
Nutrients (Total and available P, TKN, N and NH4)
mg/L Monthly
pH Monthly
Electrical Conductivity uS/cm Monthly
Organic Carbon % Bi-annually
Cations (Ca, Mg, K, Al, Na) Mg/L Monthly
Cation Exchange Capacity (CEC) cmol(+).kg
Monthly
Sodium Adsorption Ratio (SAR) Monthly
Exchangeable Sodium Percentage (ESP) of CEC
%
0-100 mm
100-300 mm
300-600 mm
600-1000 mm
Monthly
14.1.4 Wastewater from Fruit Packing System The wash water collected from the fruit packing system will be stored in a purpose built sump. This wastewater will be tested for quality to determine whether it needs to be disposed of appropriately or, if it is of suitable quality (similar to water used for irrigation), it will be reused for general use (watering of gardens or grassed areas) on site.
The sampling and analysis programme should be undertaken whenever the sump requires emptying and will include:
• pH;
• EC;
• Organics (TOC, Pesticides, DOC);
• BOD; and
• Heavy metals.
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 50
14.1.5 Vegetation, Habitat and Fauna monitoring The monitoring of the weed and pest species on site should be undertaken on a regular basis (quarterly) to ensure that activities from the horticulture operations are not exacerbating the current weed problems or increasing the number of feral species. Weed control should be undertaken as part of an annual weed control programme.
14.1.6 Dust, Noise, Spraydrift and Odour Complaints Monitoring Dust, noise, spraydrift and odours are not expected to adversely impact on neighboring stakeholders as long as horticulture operation safeguards identified in this EMP are in place. A complaints register should be established and complaints investigated. The complaints register should report the following information:
• Date and time of complaint;
• Date and time of incident;
• Location;
• Weather data to determine wind speed and direction to assist in identifying source of nuisance;
• Type of complaint – noise, dust or odour;
• Description of complaint;
• Contact details of complainant;
• Who recorded complaint;
• Who was responsible for investigating the complaint; and
• Results and outcome for investigation and follow up.
If safeguards and control measures for noise, spraydrift, dust or odours fail and complaints have been received, monitoring of these emissions should be undertaken. The monitoring activities for dust, noise, spraydrift and odour are described below:
• Dust monitoring will be undertaken following the Air Quality Standards AS 3580.10.1:2003 - Methods for sampling and analysis of ambient air. The siting of the air sampling units will require one in the location of the complainant and a background unit located upwind of the horticultural site;
• Environmental noise monitoring will be undertaken in accordance with the AS 1055.1:1997 Acoustics—Description and measurement of environmental noise, which sets out general procedures for the description and measurement of environmental noise including repetitive impulsive noise and AS 1055.2:1989 Application to specific situations;
• Monitoring of weather conditions before the use of any herbicides, fungicides, insecticides, growth regulators and fertilisers will reduce the risk of spraydrift occurring. Prior to spraying, the operators are to take into account the location of the nearby residents and other facilities on/near the site and wind conditions. Spraying should not occur during strong winds; and
• Monitoring odour is slightly more difficult, as odour recognition is a sensation resulting from the reception of a stimulus by the olfactory sensory system. The human response to an odour is only able to be evaluated depending on the particular sensory property that is being measured, including the intensity, detectability, character, and hedonic tone of the odour. The combined effect of these properties is related to the annoyance that may be caused by the odour. Therefore if a number of complaints are received (approximately
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 51
10% of the affected population) measures should be undertaken to identify the source of the odour and investigate ways to mitigate and manage.
It is also recommended that monitoring occur in the buffer zones to ensure vegetation enhancement activities have been, and continue to be, successful. These areas should have thick vegetation to assist with reducing the impact of horticultural operations (such as noise, odour and spraydrift) on neighbouring areas. Also weather conditions should be monitored and activities that can produce dust, noise, spraydrift and odour should be limited, or cease, while strong winds are blowing towards the residential areas.
14.1.7 Mosquito/Biting Insect Monitoring A vital part of a mosquito control programme is the surveillance of the site’s mosquito population. A surveillance programme will determine if mosquito control programmes are achieving population reduction or, more importantly, achieving reductions in pest problems and/or mosquito borne diseases. There are four stages to mosquito surveillance which includes1:
• Preliminary Phase – defines the nature and extent of an on site mosquito problem. It would include an information search, drawing a vector control map and initial sampling of adult and larval mosquitoes;
• Base line Data Phase – involves at least a 12 month programme, requiring regular sampling of the permanent larval and adult sampling points, collating climatic data and recording changes to mosquito habitat. This stage should also provide plans for control strategies for disease and vector control;
• Operations Phase – from the implemented mosquito control programme, regular larval and adult surveys should continue. These ongoing surveys (at the same sampling points) will indicate status of adult and larval populations in the control area. Occasionally complaints from community members may require additional and supplementary larval and adult sampling data to assist in determining the reason for increased mosquito population; and
• Evaluation Phase – after control measures have been carried out, it is most important to assess their effectiveness and to identify any remaining problems.
14.2 Environmental Management In addition to monitoring environmental conditions, it is also important to monitor the development and implementation of the environmental management processes within the horticultural operations. Environmental management is the process by which the operators of the horticultural scheme can ensure compliance to environmental legislation and minimise environmental risks.
Environmental management monitoring for the horticultural operations is as follows:
• Undertake periodic reviews and auditing of horticultural activities to ensure management actions are being carried out; and
• Periodic reviews and audit of horticultural operations using the management action tables provided in this EMP as a checklist, to ensure all environmental measures are being implemented.
1 Whelan, P. 2004. Mosquito Surveillance and Monitoring Techniques. In Mosquito Management Manual, Department of Health Western Australia
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 52
15 AUDITING Environmental auditing is an integral part of the environmental management of the horticultural operations. It is an important management tool that is a systematic, documented, periodic and objective evaluation of the environmental management practises on site. The audit assists in verifying how well the operation is performing against the OEMP and processes, to determine the level of compliance with the nominated environmental criteria.
Environmental auditing should be seen as an opportunity for the continual improvement of management practises at the site. It should be conducted during any or all stages of the proposed activities and can be undertaken in conjunction with other system audits, such as workplace health and safety, quality and contract administration, or it can be undertaken as a separate environmental audit.
15.1 Periodic Review Periodic reviews throughout the lifetime of the horticultural scheme will be required to ensure the measures set in the OEMP have been implemented. The periodic review will be undertaken by the relevant responsible bodies as described in the management sub-plans.
The periodic review of horticultural operation activities will be undertaken in the form of an informal inspection. The objectives of the review are to identify:
• Physical aspects of the operations which are not in compliance with the set requirements of this OEMP; and
• Any aspects of the horticultural operations that may have caused or have the potential to cause environmental harm.
While these inspections will be less rigorous than actual environmental audits, they play an important role in identifying non-conformances that may require immediate remedial action. These inspections can also be important mechanism for identifying areas that may need to be audited in the future. The informal inspections should be undertaken at least once per week (depending on the activities taking place on site); particularly during key development stages or activities, such as:
• The recovery of recycled water from extraction wells;
• Packaging and cold storage of produce from the site;
• During heavy rainfall events to monitor runoff from site;
• During removal of waste materials from site;
• During reuse of organic waste for operations;
• Inspection of new fill (weed free certificate) and vehicles/equipment brought on to site; and
• The storage and use of fuel and chemicals.
15.2 Environmental Audit It is recommended that environmental audits be undertaken during the operation of the horticultural venture. It is recommended that audits be undertaken at the same time corporate environmental reporting is undertaken, to integrate this process with existing environmental practises. Audits can be undertaken by relevant, trained members of an organisation’s own staff (i.e. Environmental Officer) or by external, professional auditor.
Soil Aquifer Treatment Operation Environmental Management Plan, Alice Springs Water Reuse Scheme
HLA Ref: B600270_RPT_Final_HortOEMP_11Apr05 53
The main types of audits which are recommended to be undertaken during the horticultural operations include:
• Compliance Audits - these audits are undertaken against this OEMP. The compliance audit is similar to the periodic review only it will be more thorough and the audit will be conducted by someone external to the process. It is recommended that compliance audits be undertaken bi-annually; and
• Formal Audits - these examine the environmental impacts associated with operational activities. These audits assist operators to understand not only the environmental impacts of the operations but also how its processes and activities contribute to the impacts. Formal audits will enable a continual review and update of strategies and identify any changes to legislation, regulations or policies for site operations.
15.3 Non-conformance Procedures Non-conformance procedures are those procedures that should be followed in the event that a site audit or inspection identifies a breach of the agreed environmental management strategies has occurred. These procedures apply to all personnel including any sub-contractors.
In the event of a non-conformance, the following procedures should be followed:
• Non-conformance activity should cease;
• Contact the Operations Manager, who will then contact the Environment Manager, Safety Officer or other personnel as required;
• Assess the degree of non-conformance and extent of resultant environmental impact (if any);
• Determine procedures for mitigation or management; and
• Undertake management or mitigation procedures to the satisfaction to the Environment Officer.
Each non-conformance should be documented, along with the corrective actions undertaken.
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