report on - environment protection authority · 1. northerly groundwater wells - monitoring...

Golder Associates Pty Ltd A.B.N. 64 006 107 857 Level 3, 50 Burwood Road Hawthorn, Vic 3122, Australia (PO Box 6079, Hawthorn West, 3122) Telephone (03) 8862 3500 Fax (03) 8862 3501 http://www.golder.com

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REPORT ON

GROUNDWATER RISK ASSESSMENT

CLEANAWAY LANDFILL

TULLAMARINE

Submitted to :

Cleanaway Melbourne Landfills

Western Avenue

Tullamarine Victoria

DISTRIBUTION: 4 Copies - Cleanaway Melbourne Landfills 2 Copies - Golder Associates Pty Ltd March 2004 02613641 / 050

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EXECUTIVE SUMMARY

Golder Associates (Golder) was engaged by Cleanaway Melbourne Landfills to conduct a preliminary risk assessment of groundwater surrounding the Cleanaway Prescribed Waste Landfill site at Tullamarine, Victoria. The aims of the risk assessment were provided in Condition 2.41 of the EPA Licence (HS346) for the site. This Condition is reproduced below:

“Specifically, the risk assessment must:

(a) determine whether groundwater quality objectives as specified in State environment protection policy (Groundwaters of Victoria) are being met at the premises; and

(b) include an assessment of the long-term risk of the aqueous phase and non-aqueous phases (including polychlorinated biphenyls) of leachate migrating offsite.”

Groundwater at the site occurs in the following multiple aquifers: Newer Volcanics, Tertiary Older Volcanics, Devonian granodiorite and Silurian siltstone and in the sediments of the Brighton Group and Werribee Formation. In order to establish the pathways of groundwater movement and likely human and environmental receptors that might come into contact with groundwater from the landfill, a conceptual hydrogeological model was developed.

In general, the Moonee Ponds Creek appears to be the main discharge point, controlling groundwater movement to the north of the site. The groundwater flow to the south and south-east of the site appears to be influenced by the regional groundwater movement, which is considered to be controlled by the regional groundwater discharge zones along the Arundel Creek, Steel Creek and Maribyrnong River (eventually Yarra River and Port Phillip Bay). For the purposes of the preliminary risk assessment, and based on the inferred groundwater flow direction and ultimate groundwater discharge point, the site monitoring wells were broadly classified into two groups:

1. Northerly groundwater wells - monitoring groundwater ultimately flowing towards the Moonee Ponds Creek. For the purposes of the risk assessment, these wells a herein referred to as the “Northerly Flowing Groundwater”.

2. Southerly groundwater wells monitoring groundwater likely to be flowing towards the regional discharge zones. For the purposes of the risk assessment, these wells a herein referred to as the “Southerly Flowing Groundwater”.

Based on estimated TDS concentrations, under the SEPP Groundwaters of Victoria, the background groundwater quality in all aquifers under the site was classified as Segment B (TDS range 1,001 mg/L to 3,500 mg/L). The range of beneficial uses to be protected for this Segment B are:

• maintenance of ecosystems; • potable mineral water supply; • agriculture, parks and gardens (irrigation); • stock watering; • industrial water use; • primary contact recreation such as bathing and swimming; and • buildings and structures. The monitoring data for leachate at the site, groundwater in monitoring wells around the site boundary as well as surface water and sediment in Moonee Ponds Creek were compared with screening criteria that are protective of the beneficial uses. This screening process identified a

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range of chemicals of interest. These chemicals were qualitatively assigned a rank of low, medium or high priority chemicals based on consideration of chemical concentrations, consistency of data over time and location, location(s) of the chemical exceedences, and other factors such as natural background concentrations of some inorganic compounds.

The preliminary risk assessment identified that:

1. Aqueous phase leachate is impacting on groundwater that is migrating away from the site.

2. Some groundwater quality objectives are not being met at the premises and at some locations off the premises.

3. Of the 218 chemicals analysed in groundwater, surface water and sediment, 43 were identified as “chemicals of interest” that may require further assessment, monitoring and/or management. The remaining chemicals were found to have concentrations below their respective criteria and/or detection limits and were therefore considered to pose negligible risks to the beneficial uses of groundwater.

4. Four (4) of the 43 chemicals of interest were identified as “high priority” on the basis of the degree of exceedence of criteria, spatial and temporal extents of exceedences, and the proximity of existing beneficial uses (e.g., the Moonee Ponds Creek to the north of the site). Fourteen (14) chemicals of interest were identified as “medium priority”, and the remainder of the chemicals of interest were identified as “low priority”.

5. There is no evidence of free-phase (LNAPL) in the off-site wells, although it is noted that some wells are not screened in a manner that enables observation of free-phase. The data suggest that LNAPL from the site is not migrating into Moonee Ponds Creek and it does not extend beneath land where extraction of groundwater could occur, notwithstanding that such extraction is unlikely. This indicates that people and/or the surface water environment are not likely to come into contact with the LNAPL and hence the risks are considered to be low. However, the extent of possible LNAPL migration in the southerly direction can not be completely defined. In order to ensure that this risk associated with LNAPL migration remains low in the longer term:

• additional monitoring wells should be installed to the south east, south and south west at the site boundary and possibly off site depending on the results obtained; and

• the network of wells on the site boundary and off site should continue to be monitored for the presence of LNAPL The frequency of such monitoring would need to be agreed with the EPA but is unlikely to need to exceed once every year.

6. The concentrations of chemicals in the groundwater and leachate do not suggest that DNAPL is present on the site or migrating from the site.

Overall, only a limited number of chemicals have been identified as high priority, with potential to impact the water quality of the Moonee Ponds Creek. The potential for impact of these chemicals on the Creek requires further evaluation. The concentrations of chemicals measured within the groundwater are typically low, and while some of these exceed criteria for specific beneficial uses, there has been limited impact from the landfill on groundwater beyond the boundaries of the site.

It is recommended that a supplementary risk assessment be conducted that assesses which, if any, of the chemicals of interest pose risks to the existing beneficial uses of groundwater such that appropriate management actions can be implemented to mitigate the risks.

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The actions to be addressed in such a supplementary risk assessment should be based on the ranking of the chemicals of interest and include:

1. For Low, Medium and High Priority Chemicals of Interest

• Finding, and assessing for suitability, criteria for surface water and groundwater for the chemicals of interest that have been identified on the basis of detectable concentrations only (i.e., no relevant State or National criteria were available). Agreement on the criteria will need to be reached with EPA.

• Assessing and comparing data on background groundwater quality with the concentrations of those chemicals considered to be natural background groundwater conditions. These chemicals are considered to be the inorganics barium, boron, cobalt, iron, total manganese and selenium.

• Sampling of groundwater and/or the Moonee Ponds Creek for those chemicals of interest identified on only one monitoring occasion or only at one location to confirm (or otherwise) the existing results;

2. For High Priority Chemicals of Interest Only

• Ecological risk assessments of those chemicals of interest potentially posing risks to aquatic ecosystems in the Moonee Ponds Creek. The risk assessments may involve a combination of literature data and site-specific sampling and toxicological testing.

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TABLE OF CONTENTS

SECTION PAGE 1.0 INTRODUCTION ................................................................................................................... 1

1.1 Aim....................................................................................................................... 1 1.2 Approach ............................................................................................................. 1 1.3 Methodology ........................................................................................................ 2 1.4 Organisation of this Report.................................................................................. 3

2.0 SITE AND SURROUNDS...................................................................................................... 4 2.1 Site Location........................................................................................................ 4 2.2 Nearby Surface Waterbodies .............................................................................. 4

3.0 LANDFILLING AT TULLAMARINE....................................................................................... 5 3.1 Site Operations.................................................................................................... 5 3.2 History of Tullamarine Landfill ............................................................................. 5 3.3 Future Plans for the Site...................................................................................... 6

4.0 LEGISLATIVE CONTEXT ..................................................................................................... 7 4.1 State Environment Protection Policy (Groundwaters of Victoria)........................ 7 4.2 State Environment Protection Policy (Waters of Victoria) ................................... 8

5.0 MONITORING AT TULLAMARINE..................................................................................... 10 5.1 Background ....................................................................................................... 10 5.2 Groundwater Monitoring Wells .......................................................................... 10 5.3 Leachate Monitoring Wells ................................................................................ 12

5.3.1 Aqueous Phase Leachate Quality ........................................................ 13 5.3.2 Non Aqueous Phase on Leachate........................................................ 14

5.4 Moonee Ponds Creek Monitoring...................................................................... 14 5.5 Monitoring Data for the Risk Assessment ......................................................... 16

6.0 HYDROGEOLOGICAL CONCEPTUAL MODEL............................................................... 21 6.1 Regional Geological and Hydrogeological Setting ............................................ 21 6.2 Main Geological and Hydrogeological Units...................................................... 22

6.2.1 General................................................................................................. 22 6.2.2 Silurian Dargile Formation.................................................................... 22 6.2.3 Quartzite/Silcrite ................................................................................... 22 6.2.4 Werribee Formation.............................................................................. 23 6.2.5 Older Volcanics .................................................................................... 23 6.2.6 Brighton Group ..................................................................................... 24 6.2.7 Newer Volcanics................................................................................... 25

6.3 Leachate Levels, Water Levels and Flow Direction .......................................... 25 6.3.1 General................................................................................................. 25 6.3.2 Leachate Levels ................................................................................... 27 6.3.3 Groundwater Levels and Hydraulic Gradients ..................................... 28 6.3.4 Groundwater Flow Direction................................................................. 29

7.0 MOONEE PONDS CREEK................................................................................................. 31 7.1 Introduction........................................................................................................ 31 7.2 Physical Data..................................................................................................... 31 7.3 Biological Data................................................................................................... 31 7.4 Historical Water Quality Data ............................................................................ 33 7.5 Cleanaway Data ................................................................................................ 34 7.6 Summary of Aquatic Ecosystem Condition of the Creek .................................. 37

8.0 GROUNDWATER, SURFACE WATER AND SEDIMENT CRITERIA.............................. 38 8.1 Groundwater Use in Area.................................................................................. 38 8.2 Groundwater Quality and Beneficial Uses......................................................... 38 8.3 Ground- and Surface Water Assessment Criteria............................................. 39 8.4 Sediment Criteria............................................................................................... 43 8.5 Use of Criteria.................................................................................................... 46

9.0 CHEMICAL SCREENING OF GROUNDWATER (AQUEOUS PHASE) .......................... 47 9.1 Groundwater Flowing in a Southerly Direction.................................................. 47

9.1.1 Brighton Group Groundwater ............................................................... 48

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9.1.2 Older Volcanics Groundwater .............................................................. 51 9.1.3 Werribee Formation Groundwater........................................................ 56 9.1.4 Silurian Groundwater............................................................................ 59

9.2 Groundwater Flowing in a Northerly Direction................................................... 62 9.2.1 Older Volcanics Groundwater .............................................................. 63 9.2.2 Silurian Groundwater............................................................................ 66

10.0 CHEMICAL SCREENING OF MOONEE PONDS CREEK ............................................... 70 10.1 Creek Water ...................................................................................................... 70 10.2 Creek Sediment................................................................................................. 76

11.0 PRELIMINARY RISK ASSESSMENT (AQUEOUS PHASE) ............................................ 80 11.1 Southern Groundwater ...................................................................................... 81 11.2 Northern Groundwater....................................................................................... 86 11.3 Summary of Chemical Prioritisation .................................................................. 91

12.0 PRELIMINARY RISK ASSESSMENT (NON-AQUEOUS PHASE)................................... 93 12.1 Light Non Aqueous Phase Liquid ...................................................................... 93 12.2 Dense Non Aqueous Phase Liquid ................................................................... 95

13.0 SUMMARY........................................................................................................................... 96 13.1 Approach ........................................................................................................... 96 13.2 Findings ............................................................................................................. 96

13.2.1 Aqueous Phase .................................................................................... 96 13.2.2 Non-Aqueous Phase ............................................................................ 97

13.3 Conclusions ....................................................................................................... 97 14.0 RECOMMEDATIONS.......................................................................................................... 98

14.1 Aqueous Phase ................................................................................................. 98 14.2 Non Aqueous Phase.......................................................................................... 99

15.0 REFERENCES .................................................................................................................. 100 16.0 LIMITATIONS OF THIS REPORT .................................................................................... 102

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LIST OF TABLES Table 1. Segments of the groundwater environment ......................................................................7 Table 2. Protected beneficial uses of the segments .......................................................................8 Table 3. Beneficial Uses to be Protected in the Urban Waterways Segment.................................9 Table 4. Groundwater Monitoring Wells on and around Cleanaway Tullamarine.........................11 Table 5. Leachate Monitoring Wells..............................................................................................12 Table 6. Leachate Quality since 1999...........................................................................................13 Table 7. Observed NAPL Thickness in Leachate Extraction and Monitoring Wells .....................14 Table 8. Moonee Ponds Creek Monitoring Locations ...................................................................15 Table 9. Groundwater and Surface Water Monitoring – October 2003 - January 2004 ...............17 Table 10. Schedule A Parameters ..................................................................................................19 Table 11. Schedule B Parameters ..................................................................................................20 Table 12. Aquifer Units at Tullamarine............................................................................................21 Table 13. Groundwater Levels (m AHD) .........................................................................................26 Table 14. Leachate/NAPL levels.....................................................................................................28 Table 15. Native and exotic fish species recorded in Moonee Ponds Creek..................................32 Table 16. Native fish species potentially present in Moonee Ponds Creek ....................................32 Table 17. Surface Water Quality – Moonee Ponds Creek “Upper” site ..........................................35 Table 18. Surface Water Quality – Moonee Ponds Creek “Lower” site ..........................................36 Table 19. Background TDS of Groundwater ...................................................................................38 Table 20. Groundwater and Surface Water Assessment Criteria...................................................40 Table 21. Sediment Assessment Criteria........................................................................................45 Table 22. Details of Chemical Screening for Southerly Flowing Brighton Group Groundwater .....49 Table 23. Chemicals of Interest – Southerly Flowing Brighton Group Groundwater ......................51 Table 24. Details of Chemical Screening for Southerly Flowing Older Volcanics Groundwater.....52 Table 25. Summary of Exceedences – Southerly Flowing Older Volcanics Groundwater .............56 Table 26. Details of Chemical Screening for Southerly Flowing Werribee Formation

Groundwater...............................................................................................................................58 Table 27. Summary of Exceedences – Southerly Flowing Werribee Formation Groundwater ......59 Table 28. Details of Chemical Screening for Southerly Flowing Silurian Groundwater..................60 Table 29. Summary of Exceedences – Southerly Flowing Silurian Groundwater ..........................62 Table 30. Details of Chemical Screening for Northerly Flowing Older Volcanics Groundwater .....64 Table 31. Summary of Exceedences – Northerly Flowing Older Volcanics Groundwater..............66 Table 32. Details of Chemical Screening for Northerly Flowing Silurian Groundwater ..................67 Table 33. Summary of Exceedences – Northerly Flowing Silurian Groundwater ...........................69 Table 34. Details of Screening Process for Moonee Ponds Creek Water ......................................71 Table 35. Results of Moonee Ponds Creek Water Chemical Screening ........................................75 Table 36. Details of Screening Process for Moonee Ponds Creek Sediment ................................77 Table 37. Results of Moonee Ponds Creek Sediment Chemical Screening...................................79 Table 38. Summary of Exceedences – Southerly Flowing Groundwater .......................................81 Table 39. Prioritisation of Chemicals of Interest in the Southern Groundwater ..............................83 Table 40. Linkages between Groundwater to north, Creek water and Creek sediment .................87 Table 41. Prioritisation of Chemicals of Interest in Northern Groundwater.....................................88 Table 42. Prioritisation of Chemicals of Interest ............................................................................91 Table 43. Comparison of Solubility of DNAPL Chemicals to Leachate and Groundwater

Quality ........................................................................................................................................95

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LIST OF FIGURES Figure 1 Site Location Plan Figure 2 Surrounding Surface Waterbodies Figure 3 Groundwater and leachate Well Locations Figure 4 Moonee Ponds Creek Sampling Locations Figure 5 Surface Electrical Conductivity Readings 2003 Figure 6 Base Electrical Conductivity Readings 2003 Figure 7 Water Levels, January 2004, Leachate Pumping System Off Figure 8 Geological Cross-sections AA and BB Figure 9 Inferred Contours of Groundwater Table, January 2004, Leachate Pumping

System On Figure 10 Inferred extent of light non-aqueous phase liquid (LNAPL)

LIST OF APPENDICES Appendix A EPA Licence HS346 for the site Appendix B Copies of Bore Logs Appendix C Leachate Data (1999 – 2002) Appendix D Groundwater Data (October and December 2003) Appendix E Moonee Ponds Creek Data (December 2003 and January 2004) Appendix F Copies of Laboratory Reports Appendix G Assessment of Data Quality Appendix H Copies of Kingtech Field Sampling Records Appendix I Groundwater Wells in Area Appendix J Important Information About Your Environmental Site Assessment

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1.0 INTRODUCTION Golder Associates (Golder) was engaged by Cleanaway Melbourne Landfills to conduct a preliminary risk assessment of groundwater surrounding the Cleanaway Prescribed Waste Landfill site at Tullamarine, Victoria. The aim of the preliminary risk assessment is to assess whether pollution of groundwater has occurred or is likely to occur, and to identify the chemicals of interest that are responsible for any (potential) pollution.

The requirement for the risk assessment forms part of condition 2.39 of the EPA Victoria Licence to Brambles Australia Limited (trading as Cleanaway). Specifically, the licence states that:

“…the licence holder must complete the Preliminary Risk Assessment (hereinafter referred to as the “risk assessment”) to the satisfaction of the Authority in accordance with the methodology and information specified in the report titled “Offsite Groundwater Monitoring and Risk Assessment Methodology Tullamarine Waste Disposal Site”, and as amended and approved in writing by the Authority.” (EPA 2003a)

A copy of the licence is provided in Appendix A.

1.1 Aim

The aims of the risk assessment were provided in Condition 2.41 of the EPA Licence (HS346) for the site. This Condition is reproduced below:

“Specifically, the risk assessment must:

(c) determine whether groundwater quality objectives as specified in State environment protection policy (Groundwaters of Victoria) are being met at the premises; and

(d) include an assessment of the long-term risk of the aqueous phase and non-aqueous phases (including polychlorinated biphenyls) of leachate migrating offsite.” (EPA 2003a)

1.2 Approach

The risk assessment methodology was outlined in the Golder Associates’ report “Off-site Groundwater Monitoring and Risk Assessment Methodology, Tullamarine Waste Disposal Site”, for Cleanaway Melbourne Landfills, dated February 2002 (Golder 2002). In that report, the criteria for “likelihood of pollution” were set. These were qualitative assessments of:

• the physico-chemical and toxicological properties of the contaminants of interest;

• known uses of groundwater from that aquifer unit within similar geology and within the region of the site;

• analysis of whether a pathway to the receptor actually exists (e.g., does the groundwater actually discharge to the surface waterbody); and

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• distance to the receptor (i.e., is the concentration in the groundwater used by the receptor likely to exceed the water quality objectives).

The approach to the groundwater risk assessment is consistent with the:

• State Environment Protection Policy (SEPP) Groundwaters of Victoria (GoV 1997);

• SEPP Waters of Victoria (GoV 2003) and the various Schedules contained therein (e.g., GoV 1999); and the

• National Environment Protection (Assessment of Site Contamination) Measure (NEPC 1999) and the various Schedules contained therein.

This risk assessment requires development of a hydrogeological model for the site. The purpose of developing the hydrogeological model is to provide a better understanding of possible pathways by which leachate from the landfill may enter and migrate through the groundwater system, where it may then be encountered by potential human and/or environmental receptors. This information was used to make an assessment of the potential beneficial uses of groundwater in each main aquifer system in each down gradient groundwater flow direction from the landfill. The output of the hydrogeological model was the identification of the potential pathways of exposure to groundwater of various receptors (human and ecological) associated with potential and existing beneficial uses.

The primary legislation that frames this preliminary risk assessment is the State Environment Protection Policy (SEPP) – Groundwaters of Victoria (GoV (1997). The Groundwaters of Victoria SEPP provides guidance on which water quality objectives should be used to identify the chemicals of interest that are considered under the SEPP to be potentially causing pollution of groundwater. Surface water quality objectives are provided in other legislation and guidance such as the SEPP Waters of Victoria (GoV 2003), the Australian Water Quality Guidelines for Fresh and Marine Waters (ANZECC 1992) and the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC and ARMCANZ 2000).

1.3 Methodology

The methodology used for this preliminary risk assessment of groundwater was agreed with EPA in June 2002 and is described below.

1. On the basis of the hydrogeological model, groundwater data were divided into north and south, and separately assessed. The northern groundwater data were grouped with water and sediment data from the Moonee Ponds Creek. The rationale for this approach is provided in section 6.0.

2. Measured concentrations of chemicals in the groundwater were compared with published criteria (or detection limits, where no criteria were available) for the protection of the various beneficial uses of the groundwater. Chemicals that were found to be below criteria and/or detection limits in all wells on all monitoring occasions were not considered further as agreed with EPA in April and June 2003. Chemicals that were

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above criteria and/or detection limits were identified as “chemicals of interest”. Water and sediment data from the Moonee Ponds Creek was assessed in the same way as the groundwater, with the appropriate surface water criteria used as the basis of comparison (refer section 8.0).

3. Each of the identified chemicals of interest was then individually ranked to provide a basis for prioritising the further assessment or management of the risk.

It is expected that further risk assessment will need to be conducted subsequent to this report to establish whether management actions are required to mitigate the risks posed by the high priority chemicals.

1.4 Organisation of this Report

The report is organised into the following sections:

1. Introduction

2. Site and Surrounds

3. Landfilling at Tullamarine

4. Legislative context

5. History of data collection at Tullamarine relevant to the risk assessment

6. Hydrogeological model

7. Moonee Ponds Creek

8. Groundwater, surface water and sediment criteria

9. Chemical Screening of Groundwater (aqueous phase)

10. Chemical Screening of Moonee Ponds Creek

11. Preliminary Risk Assessment (Aqueous Phase)

12. Preliminary Risk Assessment (Non-Aqueous Phase)

13. Summary

14. Recommendations

15. References

16. Limitations

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2.0 SITE AND SURROUNDS

2.1 Site Location Cleanaway’s Tullamarine Landfill occupies approximately 20 ha of land on Western Avenue, 17 km north-west of Melbourne, adjacent to the Tullamarine International Airport and in the City of Hume municipality (refer Figure 1). The site is bordered by the Tullamarine Freeway to the south, Moonee Ponds Creek to the north, buffer land owned by Cleanaway (intersected by Victoria Street) to the east, and filled land to the immediate west and industrial land further to the west (Figure 1). Residential housing lies beyond the buffer zone to the east of the site. A fuel depot lies to the north-west of the site. Tullamarine Airport occupies land to the west, north-west and south of the site.

To the north of Moonee Ponds Creek, opposite the site, lies a former quarrying area. To the east of this area lies open land with a recreational path to the Woodlands Historic Park, an open park of remnant grassland and vegetation. East of the path lies pastoral and grazing land.

2.2 Nearby Surface Waterbodies

The nearest surface water body to the Cleanaway Tullamarine Landfill is the Moonee Ponds Creek, which provides a northern boundary to the site and flows in south-east to easterly direction in this location. Moonee Ponds Creek flows into the Yarra River approximately 17 km1 south-east of the site. Approximately 4.5 km south-southeast of the site lies Steele Creek, also flowing in a south-easterly direction. Steele Creek discharges to the Maribyrnong River approximately 6.5 km to the south-southeast of the site. The Maribyrnong flows into the Yarra River, which in turn flows into Port Phillip Bay. An unnamed Creek (a branch of Steele Creek) flowing south into Steele Creek lies approximately 2.5 km to the south of the site. Due west, the Maribyrnong River (flowing south at this location) comes within five kilometres of the Cleanaway Tullamarine site. Between the Maribyrnong River to the west and the site lies the Arundel Creek, flowing in a southerly direction into the Maribyrnong River. The Moonee Ponds Creek, Steele Creek, Arundel Creek and the Maribyrnong River are all in the Yarra River catchment. Figure 2 shows the location of the various surface waterbodies around the site.

1 This distance is the straight overland distance from Creek to River, not the downstream Creek distance to the River.

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3.0 LANDFILLING AT TULLAMARINE

3.1 Site Operations

The Cleanaway Tullamarine Landfill is one of two landfills in Victoria specifically engineered to receive Prescribed Industrial Waste. Prescribed Industrial Wastes1 are those wastes of commercial or industrial origin which have the potential to cause environmental hazard because of their physical or chemical properties, or infectious or odorous nature. These wastes can be in liquid or solid form, or something in between (e.g., sludges and slurries). The site accepts solid Prescribed Industrial Waste only.

The site consists of three mounds where waste has been placed, a leachate treatment plant with treatment lagoons, monitoring bores, leachate wells and a recently installed leachate collection system consisting of a network of leachate extraction wells which are designed to collect and/or monitor aqueous leachate and separate phase (i.e., oily) leachate. The three mounds where waste filling occurred are referred to as Mounds 1 to 3 (Figure 3).

The site operates under an EPA Victoria licence number HS346 (EPA 2003a), which requires that Cleanaway meet environmental quality requirements for all segments of the environment. This includes meeting the general provisions of the Environment Protection Act 1970, State environment protection policies and industrial waste management policies. Environmental quality monitoring at and around the site includes monitoring of groundwater, surface water, leachate and air emissions.

3.2 History of Tullamarine Landfill

Cleanaway’s Tullamarine landfill was established in an extractive industry quarry, which provided stone for construction purposes. The operations were situated on a strip of land with the dimensions of 1,000 m by 500 m, with an estimated excavation depth of 30 m. The volume of the hole has been estimated to be 10 million m3 (Shugg 1994).

Landfilling at the site commenced in May 1972 (Golder 1965). By the early 1970s, the Tullamarine Landfill received an average of around 480,000 m3/yr of solid, non-putrescible industrial wastes and 86,000 m3/yr of industrial liquid waste (Shugg 1994).

Early in the history of the site the co-disposal of liquid and solid waste at the site was termed the “Bio-Bed” disposal technique. Craters were constructed in the solid waste into which liquids were poured. The craters acted as leaky turkey nest dams2. Acid and alkali wastes were segregated. Excess liquids formed a leachate which drained to pools at the toe of the landfill. As the landfill filled, wells were also constructed to collect the leachate. From the collection pools or wells, the leachate was pumped up to three treatment lagoons located in 1 Prescribed industrial wastes are wastes of a commercial or industrial origin, generated in the production of everyday goods and services that the community expects to be carefully managed and closely regulated. A waste may be classified as a prescribed industrial waste for a range of reasons including amenity, toxicity, leachability and flammability. 2 A small earth dam constructed from spoil excavated to form a hollow and placed as a bund around the perimeter

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the area now covered by Mound 3. The treatment lagoons provided oil separation, aeration and lime neutralisation. In the early operation of the site, surplus leachate was managed using spray evaporation. This practice was discontinued due to odour and water budget problems. The site has maintained its operation by adopting leachate treatment and effluent disposal to the sewer (Shugg 1994). Liquid wastes were not received at the site after 1987.

During the early 1970s, a groundwater contamination plume was detected in the Brighton Group Sands to the south east of the site. The Brighton Group sands are of higher permeability than other geological units in the area. As a result of the detection of this contamination, construction of a compacted clay liner around the perimeter of the landfill was commenced in 1976. This compacted clay liner forms a sub-vertical wall extending from the top of the Older Volcanics basalt (at the base of the landfill) to the rim of the landfill. It was constructed from clay sourced from on-site and off-site sources and was compacted to achieve a hydraulic conductivity of not more than 1 x 10-9 m/s. The clay liner construction was commenced on the northern side of Mound 1 and was progressively constructed clockwise around the eastern and southern sides of Mound 1. It was then extended around the southern and western perimeters of Mound 2 and then the northern and eastern perimeters of Mound 3, linking into the liner at the north side of Mound 1. Additional vertical extensions of the wall have been constructed for specific purposes such as to facilitate current filling operations in the south-west part of Mound 2.

The landfill contains a wide inventory of wastes, consisting of industrial solids and liquids, inert waste, contaminated soils, hazardous substances, acids, alkalis and contingency disposal consignments.

3.3 Future Plans for the Site

In accordance with the site licence, Mounds 1 and 2 have been capped with a 0.5 m thick compacted clay liner and covered with soil. Vapour collection drainage blankets were constructed in the upper parts of the mounds to facilitate vapour collection, if ever needed. In 2001 Cleanaway was granted Works Approval to modify the landfill to accommodate further landfilling of waste in the Mound 1 and 2 area. As part of the Works Approval, Cleanaway agreed to install a best practice capping system comprising:

0.5 m compacted clay liner;

1 mm geomembrane liner; and

0.75 m of cover soil.

This upgraded capping system is to be installed over the entire landfill with the first stage of capping currently being constructed over Mound 3. Upgraded capping will be installed over Mounds 1 and 2 following completion of filling in these areas.

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4.0 LEGISLATIVE CONTEXT

State Environment Protection Policies (SEPPs) set out policies of the State Government to control and reduce environmental pollution and have been formulated for discharges to land, atmosphere, water, groundwater and noise emissions. They protect the environment from pollution, caused by waste discharges and noise. The relevant SEPPs for groundwater and surface water at the Cleanaway Tullamarine Landfill site are the Groundwaters of Victoria SEPP (GoV 1997) and the Waters of Victoria SEPP (GoV 2003). These are discussed further below.

4.1 State Environment Protection Policy (Groundwaters of Victoria)

The State Environment Protection Policy “Groundwaters of Victoria” (GoV 1997) is a policy which provides a framework for the protection of groundwaters throughout Victoria. This policy defines the beneficial uses to be protected based on segments of the groundwater environment, which are in turn based on the total dissolved solids (TDS) loading of the background groundwater within an aquifer unit. Table 1 shows how the Groundwaters of Victoria SEPP divides the segments of the groundwater environment on the basis of TDS.

Table 1. Segments of the groundwater environment

Segment A1 A2 B C D TDS range (mg/L)

0 – 500 501 – 1,000 1,001 - 3,500 3,501 – 13,000 Greater than

13,000

The Groundwaters of Victoria SEPP lists beneficial uses of groundwater for each segment of the groundwater environment. Groundwater of a particular segment must be protected for the nominated beneficial uses. In practice, any protective actions or management of groundwater are prioritised to those beneficial uses that are likely or existing. The beneficial uses for each segment of the groundwater environment are provided in Table 2.

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Table 2. Protected beneficial uses of the segments

Segments (mg/L TDS)

Beneficial Uses A1

0 – 500 A2

501 – 1,000

B 1,001 - 3,500

C 3,501 – 13,000

D Greater

than 13,000

1. Maintenance of ecosystems 2. Potable water supply Desirable Acceptable

3. Potable mineral water supply

4. Agriculture, parks and gardens

5. Stock watering 6. Industrial water use 7. Primary contact recreation

(e.g., bathing, swimming)

8. Buildings and structures

In order to classify groundwater quality at, and in the vicinity of, the Tullamarine Landfill, an understanding is required of the various aquifers beneath the site and their background TDS concentration. The hydrogeological model developed for the site is discussed further in section 6.0. Based on this model, the classification of groundwater in the vicinity of the Cleanaway Tullamarine Landfill is discussed in section 8.1, and the appropriate chemical criteria for use in assessing the condition of the groundwater are provided in section 8.3.

4.2 State Environment Protection Policy (Waters of Victoria)

Surface water bodies in Victoria are protected under the State Environment Protection Policy, Waters of Victoria (WoV) (GoV 2003) and its Schedules. The Yarra River catchment lies in Schedule F7 of WoV (Waters of the Yarra Catchment, GoV 1999). As with the Groundwaters of Victoria SEPP, Schedule F7 defines the beneficial uses of water to be protected based on segments of the surface water environment. Under Section 6 of Schedule F7 of WoV, the Maribyrnong River, Moonee Ponds Creek, Steele Creek and Arundel Creek are classified in the Urban Waterways Segment of the surface water environment. For each listed Segment of the surface water environment, Schedule F7 lists the beneficial uses to be protected. The beneficial uses to be protected for the Urban Waterways Segment are shown in Table 3.

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Table 3. Beneficial Uses to be Protected in the Urban Waterways Segment

Beneficial Uses Urban Waterways Segment

Maintenance of natural aquatic ecosystems and associated wildlife Modified ecosystems

Passage of indigenous fish Maintenance of indigenous riparian vegetation Water based recreation Primary contact (e.g., swimming, water skiing) Secondary contact (e.g., boating, fishing) Aesthetic enjoyment (e.g., walking by the waters)

Commercial and recreational use of edible fish and crustacea

Agricultural water supply Stock water Irrigation (including watering parks and gardens)

Industrial water use

Schedule F7, and the amendments under WoV (GoV 2003), provide environmental quality indicators and objectives for the urban waterways segment of surface water. Criteria for the Urban Waterways Segment of the surface water environment are provided under Schedule F7 of WoV (GoV 1999) for temperature, pH, salinity, dissolved oxygen, turbidity, nutrients and E. coli. For toxicants, the amendments under WoV (GoV 2003) state that the values specified for protection of aquatic ecosystems in the ANZECC and ARMCANZ (2000) Guidelines for Fresh and Marine Water Quality (the “Guidelines”) should be used.

The Guidelines provide criteria for fresh and marine waters for different levels of ecosystem protection: 99%, 95%, 90% and 80%. The level of ecosystem protection in the Guidelines that needs to be used to determine the criteria is:

• 99% for largely unmodified aquatic ecosystems;

• 95% for slightly to moderately modified aquatic ecosystems;

• 90% for highly modified ecosystems.

A discussion of the ecosystem condition of the Moonee Ponds Creek is provided in section 7.6. The appropriate criteria to be used for the Creek are provided in section 8.3.

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5.0 MONITORING AT TULLAMARINE

5.1 Background

An extensive groundwater well, leachate well and Moonee Ponds Creek monitoring system currently exists at the Cleanaway Tullamarine site. Gas monitoring at the site is also conducted as part of the EPA Victoria Licence requirements. However, the results of the gas monitoring will not be discussed in this report.

The monitoring locations at Cleanaway Tullamarine can be broadly divided into:

• groundwater monitoring wells, which can be further divided into wells that are:

• onsite;

• offsite;

• in the buffer zone to the east;

• on the Moonee Ponds Creek bank; and

• in the Tullamarine Freeway.

• leachate monitoring wells; and

• Moonee Ponds Creek monitoring locations.

The well logs, showing construction details, location (in easting and northing) and completion date, are shown in Appendix B. The following sections discuss each of the above groups of monitoring wells/locations and the frequency of the monitoring.

5.2 Groundwater Monitoring Wells

There are currently 39 groundwater monitoring wells (some of which are paired wells) on and around the Tullamarine Cleanaway site. Of these, 18 well require quarterly monitoring as part of the EPA Licence (EPA 2003a) requirements for the site.

The groundwater well identifiers, location and grouping are shown in Table 4. Bore-logs1 are provided in Appendix B. The wells that require monitoring as part of the EPA Licence requirements for the site are indicated in bold. In addition, Table 4 divides the monitoring wells by inferred groundwater flow direction (northerly or southerly), based on the hydrogeological model discussed in section 6.0. Groundwater flow direction is important for the discussion on the risks posed by any groundwater pollution (refer section 11.0). Figure 3 shows the groundwater monitoring well locations on and around the site.

Data on groundwater monitoring at the site dates back to at least 1974. Historically, samples of groundwater were analysed for total dissolved solids (TDS), a range of inorganic compounds, metals and selected organics. Over the last several years the analytical suite for groundwater samples has considerably expanded to include a range of compounds detected in

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the leachate from the site (refer section 5.3). The current EPA Licence for the site requires that groundwater samples collected as part of the Licence requirements are analysed for a specific suite of organic and inorganic parameters, which is provided in the Licence. This suite of parameters is the same as that required for leachate samples (refer section 5.3 and Table 5).

Table 4. Groundwater Monitoring Wells on and around Cleanaway Tullamarine

Well Identifier

Date completed Aquifer Location

Wells with Northerly Groundwater Flow Direction MB9U 1999 Brighton Group On-site 10006 1974 Older Volcanics / Silurian siltstone On-site BH2* 2002 Older Volcanics Buffer zone BH3* 2002 Older Volcanics / Silurian siltstone Buffer zone MB6U 1980 Older Volcanics On-site MB9L 1999 Older Volcanics On-site MB13 2003 Older Volcanics Buffer zone MB23 2003 Older Volcanics Moonee Ponds Creek bank MB14 2003 Silcrete Buffer zone MB6L 1980 Silurian siltstone On-site MB10 2000 Silurian siltstone Moonee Ponds Creek bank MB11 2000 Silurian siltstone Moonee Ponds Creek bank MB12 2003 Silurian siltstone Moonee Ponds Creek bank MB24 2003 Silurian siltstone Moonee Ponds Creek bank Wells with Southerly Groundwater Flow Direction Tulla3U 1971 Brighton Group On-site MB4UR 1999 Brighton Group On-site MB7U 1999 Brighton Group On-site MB8U 1999 Brighton Group On-site MB16 2003 Brighton Group Buffer zone MB15 2003 Brighton Group / Older Volcanics Buffer zone 10005 1973 Older Volcanics On-site 97005R* 2003 Older Volcanics Off-site 97007* 1980 Older Volcanics Off-site BH1* 2002 Older Volcanics Buffer zone Tulla3L 1971 Older Volcanics/Silurian siltstone On-site MB4LB2 1985 Older Volcanics On-site MB5UR 2001 Older Volcanics On-site MB7L 1999 Older Volcanics / Silurian siltstone On-site MB8L 1999 Older Volcanics On-site MB17 2003 Older Volcanics Buffer zone MB20 2003 Older Volcanics Tullamarine Freeway MB21 2003 Older Volcanics Tullamarine Freeway MB22 2003 Older Volcanics Tullamarine Freeway MB5LR 2001 Werribee formation On-site MB19 2003 Silcrete Tullamarine Freeway MB18 2003 Silurian silstone Tullamarine Freeway Wells in bold require monitoring as part of the EPA Licence for the site * Not a Cleanaway monitoring well; “R” = replacement well Paired wells have the “L” (lower) and “U” (upper) suffixes Paired wells without the L and U suffixes are: MB13 (shallow) and MB14 (deep); MB23 (shallow) and MB24 (deep); MB16 (shallow) and MB17 (deep); MB21 (deep) and MB22 (shallow)

1 Bore-logs for wells MB6U and MB6L were not available for inclusion in this report. 2 This well has been referred to as MB4LR in groundwater sampling reports and analytical laboratory reports, and as MB4B in the bore-log. The correct well name is MB4LB.

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5.3 Leachate Monitoring Wells

There are currently 18 leachate wells on the Cleanaway Tullamarine site. Wells L1 to L6, L8 and L9 currently form part of the leachate collection system on the site. Wells W6, W8, W11, W12, W13, W15, W17, T1 T2 and T3 are large diameter concrete wells, intended to be used for leachate extraction. They are now used occasionally for monitoring purposes. Wells LB1 and LB2 were installed as part of a leachate pumping trial in 1999. These are small diameter wells, not currently used for leachate extraction, but occasionally used for monitoring leachate levels.

Condition 2.35 of the EPA Licence for the site (EPA 2003a) requires that at least seven leachate extraction wells are used to extract leachate from the Cleanaway Tullamarine Landfill site. Those wells considered in the licence to be leachate extraction wells are wells L1 to L6, L8, L9, W6, W13, W15, W17 and well T3.

Well identifiers and installation dates of the leachate monitoring wells are shown below in Table 5. The leachate wells that comprise the leachate extraction wells operated at the site required as part of the EPA Licence requirements (EPA 2003a) are indicated in bold in Table 5. Figure 3 shows the locations of the leachate wells on the site. Bore-logs for the leachate wells (excluding the old wells installed in the late 1970s / early 1980s and early 1990s) are provided in Appendix B.

Table 5. Leachate Monitoring Wells

Well Identifier Date completed Screen Location

L1 2002 Waste L2 2002 Waste L3 2002 Waste L4 2002 Waste L5 2002 Waste L6 2002 Waste L8 2002 Waste L9 2002 Waste LB1 1999 Waste LB2 1999 Waste Well 6* Late 1970s/early 1980s Waste Well 8* Late 1970s/early 1980s Waste Well 11* Late 1970s/early 1980s Waste Well 12 Late 1970s/early 1980s Waste Well 13* Late 1970s/early 1980s Waste Well 15* Late 1970s/early 1980s Waste Well 17* Late 1970s/early 1980s Waste Well T1* Early 1990s Waste Well T2 Early 1990s Waste Well T3* Early 1990s Waste Wells in bold form part of the leachate collection system required as part of the EPA Licence for the site *Large diameter wells originally installed as leachate pumping wells. Borelogs are in Appendix B.

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5.3.1 Aqueous Phase Leachate Quality The Licence for the site requires quarterly leachate quality monitoring for the parameters shown in Table 6. Typical concentrations / values of these parameters since 1999 are also shown in Table 6.

Table 6. Leachate Quality since 1999

Chemical / Parameter Value / Concentration Range since 1999 (mg/L)

Anion / cation balance Sodium 190 – 7,500 Potassium 27 – 520 Calcium 15 – 520 Magnesium 22 – 360 Chloride 180 – 13,000 Carbonate <2 – 1,800 Nitrates (as N) <0.01 – 7.6 TDS 1,000 – 24,000 Electrical conductivity 1,600 – 41,000 pH 7.2 – 8.2 Arsenic <0.001 – 0.34 Lead <0.001 – 4.3 Total iron 0.4 – 100 Total chromium 0.01 – 5.2 Zinc 0.03 – 200 Cadmium <0.0001 – 0.9 Mercury <0.001 – 0.01 Copper <0.01 – 1.7 Total nitrogen (as N) 4.5 – 2,400 Anionic surfactants 0.1 – 9.7 Alkalinity as CaCO3 230 – 14,000 Phenolic substances <0.005 – 2.3 Ammonia (as N) <0.3 – 2,300 Sulfate as sulfate <5 – 480 Cyanide as cyanide <0.01 – 0.7 Benzene <0.001 – 0.65 Toluene <0.001 – 0.54 Ethyl benzene <0.001 – 1.6 Xylene <0.001 – 3.7 Chlorinated hydrocarbons <0.001 – 5.3 Polychlorinated biphenyls <0.005 – 0.1

In addition to the parameters shown in Table 6, samples of leachate have also been monitored for additional metals (e.g., aluminium, barium, cobalt, iron, lead, manganese, molybdenum, inter alia), polynuclear aromatic hydrocarbons (PAHs), toxic substances (e.g., aniline, Bisphenol A, inter alia), ethers, organochlorine pesticides, chlorinated hydrocarbons, nitrogen-phosphorus pesticides, nitrosamines, volatile organic compounds, total petroleum hydrocarbons (TPHs), organotin compounds, and pyridines as well as specific organic compounds such as aliphatic alkanes. Full tables of the leachate data are provided in Appendix C.

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5.3.2 Non Aqueous Phase on Leachate Prior to commencement of the leachate extraction from mounds 1 and 2, light non aqueous phase liquid (LNAPL) was observed at thicknesses ranging from 0 up to approximately 6 metres in the leachate extraction wells L1 to L9 (Table 7). The LANPL thickness has recently been measured following 7 months of leachate extraction (Table 7 and Figure 8). In general the thickness of NAPL appears to be reducing in the leachate wells, with the exception of Well LB2.

Table 7. Observed NAPL Thickness in Leachate Extraction and Monitoring Wells

Well ID January / September 2002

Prior to pumping (m)

January 2004 Pumping since June 2003

(m) L1 5.4 5.6 L2 5.6 0 L3 4.3 1.0 L4 4.4 Not able to be determined L5 1.0 Not able to be determined L6 0 0 L8 2.7 3.3 L9 5.8 1.6 WELL 11 0* 0 WELL 12 0* 0 WELL 13 0* 0 WELL 15 0** Not able to be determined WELL 17 0* Dry WELL T1 0* NA WELL T2 0* Dry WELL T3 0* Dry WELL 6 0.8* Not able to be determined WELL 8 0.8* 0 LB1 NA* Dry LB2 NA* 5.6

(*) Measured in January 2002 (**) LNAPL currently being re-injected into this well. NA – Not available

5.4 Moonee Ponds Creek Monitoring

The Moonee Ponds Creek has been monitored for water quality over at least the last decade. Monitoring was originally conducted by Cleanaway at two locations: “Upper” and “Lower” throughout the period 1992 to 2003. The Upper location on the Creek lies approximately at the north-western boundary of the site, adjacent to the Creek. The Lower location on the Creek lies approximately opposite the north-eastern boundary of the site. The Upper and Lower sampling locations on Moonee Ponds Creek are shown on Figure 4. Data from the Upper and Lower locations are discussed in the context of the ecosystem condition of the Creek in section 7.5.

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The historical water quality data from the Upper and Lower Moonee Ponds Creek sites indicated that the Upper sampling location may not be upstream of the influence of groundwater discharging from the site. Similarly, the Lower sampling location may not have been sufficiently downstream of the influence of groundwater discharging from the site. Hence, a program of monitoring to assess Moonee Ponds Creek water further upsteam of the Upper site and further downstream of the Lower site was proposed.

More extensive monitoring of Creek water quality was conducted during the period December 2002 to February 2003. Sixteen locations were selected along a 1.8 km stretch of Creek, that included locations at, upstream of and downstream of the expected groundwater discharge points from the Cleanaway site (refer Figure 4 and Table 8). The monitoring program involved in-situ measurements of pH, temperature, electrical conductivity (EC) and redox potential. Data were collected at different depths and across the width of the Creek at each location, where possible.

Table 8. Moonee Ponds Creek Monitoring Locations

Well Identifier Easting Northing Date monitored

Upper Creek Not surveyed 1992-2003 Lower Creek Not surveyed 1992-2003 MPCL01 311170.57 5828851.91 12/02 & 02/03 MPCL02 311155.15 5828871.66 2002-2004 MPCL03 311128.38 5828864.53 12/02 & 02/03 MPCL04 311156.10 5828783.00 2002-2004 MPCL05 311205.07 5828679.14 12/02 & 02/03 MPCL06 311286.29 5828603.34 12/02 & 02/03 MPCL07 311354.08 5828499.05 2002-2004 MPCL08 311501.37 5828356.48 2002-2004 MPCL09 311619.42 5828378.50 2002-2004 MPCL10 311744.86 5828412.87 12/02 & 02/03 MPCL11 311789.33 5828370.89 12/02 & 02/03 MPCL12 311908.32 5828327.07 12/02 & 02/03 MPCL13 312012.62 5828313.95 2002-2004 MPCL14 312132.90 5828262.70 12/02 & 02/03 MPCL15 312175.60 5828275.56 2002-2004

A letter report on the finding was prepared by Golder Associates in February 2003 (Reference 02613641/008). In summary, EC was found to be the most variable parameter between the monitoring sites. Groundwater with a significantly higher EC concentration was found to be discharging to the Creek between Locations 6 and 12, which are opposite and downstream of the Cleanaway site (refer Figure 3). Deeper water in the Creek was characterised by higher EC readings than shallower, surface water. Downstream of Location 13, the effect of high EC groundwater discharge appeared to dissipate. Results of the EC readings are shown in Figure 5 and Figure 6.

While groundwater discharge to surface water is a natural process, it was possible that the groundwater discharging to the Creek was affected by leachate from the landfill. Therefore, based on the initial results from the Creek, a sampling programme of water and sediment in

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the Creek was recommended. The recommended sampling programme included seven locations as follows:

• upgradient of groundwater discharge at Location 2 (included as per EPA recommendation);

• upgradient of groundwater discharge at Location 4;

• within the central zone of groundwater discharge, downstream of the landfill at Locations 7, 8 and 9; and

• downgradient of the main groundwater discharge, Locations 13 and 15.

The results of this monitoring were used to assess the potential for risk to aquatic ecosystems of the Creek. The details of the assessment are provided in section 10.0.

5.5 Monitoring Data for the Risk Assessment

For the purposes of the risk assessment identified in the EPA Licence for the site, a concentrated effort of groundwater, surface water and sediment sampling and analysis occurred over the period October 2003 to January 2004. The work involved:

• collecting samples of groundwater in October and December 2003 from wells 10006, MB6U, MB8L, MB13, MB23, MB14, MB6L, MB10, MB11, MB12 and MB24 in the north of the site and wells Tulla3U, MB4UR, MB16, MB15, 10005, Tulla3L, ME4LB, MB5UR, MB7L, MB8L MB17 and MB20 in the south of the site.

• collecting samples of Moonee Ponds Creek water and sediment at locations MPCL02, MPLC04, MPCL07, MPCL08, MPCL09, MPCL13 and MPCL15 in December 2003 and January 2004.

The sampling was conducted by Kingtech Services, Kendarra Electrical Contractors and Golder Associates. Copies of the Kingtech Field Sampling Records are provided in Appendix H. Details of the dates and types of sampling are provided in Table 9 below. Note that this table does not show the complete list of monitoring conducted over 2003.

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Table 9. Groundwater and Surface Water Monitoring – October 2003 - January 2004

Date Type of Measurement Round Locations Conducted by Laboratory

13-24/10/03 Sampling Round 1 Off site groundwater wells MB12 – MB24

Kingtech Services & Golder Associates

Leeder Consulting & AGAL (NSW)

8-24/12/03 Sampling Round 2 Off site groundwater wells MB12 – MB24



10/11/03 Levels Round 1

Off site groundwater wells MB12 – MB24, older buffer zone Bores A, B and C, DNRE Bores 97005 and 97007, on site bores Tulla 3U/L, MB4UR, MB4LB, MB5UR, MB5LR, MB6U/L, MB7U/L, MB8U/L, MB9U/L, 10005, 10006, MB10 & MB11

Kingtech Services & SKM

-

27/01/04 Levels Round 2

Off site groundwater wells MB12 – MB24, older buffer zone Bores A, B and C, DNRE Bores 97005 and 97007, on site bores Tulla 3U/L, MB4UR, MB4LB, MB5UR, MB5LR, MB6U/L, MB7U/L, MB8U/L, MB9U/L, 10005, 10006, MB10 & MB11

Kingtech Services & SKM

-

8-24/12/03 Sampling Round 1 Moonee Ponds Creek Locations 2, 4, 7, 8, 9, 13 and 15



21-22/01/04 Sampling Round 2 Moonee Ponds Creek Locations 2, 4, 7, 8, 9, 13 and 15



27/01/04 Levels Round 1 Moonee Ponds Creek Locations 2, 4, 7, 8, 9, 13 and 15

Kingtech Services & Landair Surveyors

-

27/01/04 Levels Round 1 Leachate Wells 6, 8, 11, 12, 13, 15, 17, T2, T3, LB1, LB2, L1, L2, L3, L6, L8 and L9

Kendarra Electrical Contractors

-

The samples of groundwater and Moonee Ponds Creek surface water and sediment were analysed for a large suite of inorganic and organic parameters, termed Schedule A parameters and Schedule B parameters. Schedule A parameters are the same as those listed in Condition 3.6 of Cleanaway Tullamarine’s EPA Waste Discharge Licence (refer Appendix A), with the addition of volatile organic compounds (VOCs). These compounds were added as per EPA’s request to assess for the presence of dense non-aqueous phase liquid (DNAPL). Schedule B parameters are the same as detected in leachate samples (leachate liquid and phase-separated product) collected from leachate wells located within the landfill and sampled in October

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2002 (refer Appendix C). Schedule A parameters are shown in Table 10 and Schedule B parameters are shown in Table 11.

Both primary and secondary laboratories were involved in the analysis. The primary laboratories were Leeder Consulting for all analytes except mercury and silver in off-site bores, and WSL Consultants for standard licence parameters in on-site bores. The secondary laboratory was AGAL for silver and mercury analysis.

Groundwater and leachate (aqueous phase and NAPL) levels have also been monitored in the on-site and off-site wells. The level data are discussed to in the hydrogeological model (section 6.0) and non-aqueous phase risk assessment (section 12.0) sections of this report.

The focus of this report has been on the groundwater, surface water and sediment data collected throughout the period October 2003 to January 2004. Leachate and historical data has been referenced, where appropriate.

Full tables of leachate, groundwater and surface water data are provided in Appendix C, Appendix D and Appendix E, respectively. Copies of laboratory reports are provided in Appendix F. A discussion of the data quality is provided in Appendix G. Copies of the field sampling records are provided in Appendix H.

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Table 10. Schedule A Parameters

Anions/cations etc. Non-Metallic Inorganics Volatile Organic Compounds

Sodium Cyanide Vinyl Chloride Potassium Ammonia as N 1,1-Dichloroethene Calcium Total Kjeldahl Nitrogen 1,2-Dichloroethene (trans) Magnesium 1,2-Dichloroethene (cis) Chloride Polychlorinated Biphenyls 1,1-Dichloroethane Fluoride Aroclor 1016 Dichloromethane Carbonate Aroclor 1221 Bromochloromethane Bicarbonate Aroclor 1232 Chloroform Nitrate as NO3 2- Aroclor 1242 1,1,1-trichloroethane Sulphate as SO4 2- Aroclor 1248 1,2 -dichloroethane Total Dissolved Solids (TDS) Aroclor 1254 1,1- dichloropropene Total Organic Carbon Aroclor 1260 Carbon tetrachloride Total Alkalinity Aroclor 1262 Benzene Total Hardness Aroclor 1268 Trichloroethylene Conductivity (uS/cm) Total PCBs 1,2-dichlorpropane pH (pH units) Dibromomethane Anionic Surfactants(as MBAS) Phenols Bromodichloromethane Phenol 1,3-dichloropropene Metals cresols Toluene Arsenic 2-chlorophenol 1,1,2-trichloroethane Cadmium 4-chlorophenol 1,3-dichloropropane Chromium 2,3-dichlorophenol Dibromochloromethane Chromium (VI) 2,4-dichlorophenol Tetrachloroethylene Copper 2,6-dichlorophenol 1,2-dibromoethane Total iron 2,4,6-trichlorophenol 1,1,1,2-tetrachloroethane Lead 2,3,4,6-tetrachlorophenol Ethyl benzene Mercury pentachlorophenol m-xylene Silver 4-chloro-m-cresol o-xylene Zinc 2,4-dimethylphenol p-xylene 2-methyl-4,6-dinitrophenol Xylenes Chlorinated Hydrocarbons 2-nitrophenol Styrene 2-chloronaphthalene 4-nitrophenol Tribromomethane benzotrichloride 2,4-dinitrophenol 1,1,2,2-tetrachloroethane Hexachlorobenzene 2,4,6-trinitrophenyl Isopropylbenzene Hexachlorobutadine hexachlorophene 1,2,3,-trichloropropane Hexachlorocyclopentadene dinoseb(DNBP) Bromobenzene Hexachloroethane 2- chlorotoluene Hexachloropropene n-propylbenzene Pentachlorobenzene 4-chlorotoluene 1,2,4,5-tetrachlorobenzene 1,2,4-trimethylbenzene 1,2,4-trichlorobenzene Carbon disulfide 1,2,3-trichlorobenzene Methyl Ethylketone Chlorobenzene Methyl iosbutylketone 1,4-dichlorobenzene Acetone 1,3-dichlorobenzene 1,2-dichlorobenzene Pentachloroethane

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Table 11. Schedule B Parameters

Additional Metals Additional Semi volatiles Additional Anlaytes Aluminium Eucalyptol Decane Barium Camphor Undecane Boron Benzoic acid, p-tert butyl- Dodecane Chromium (III) 2(3H) Benzothoazolone Tridecane Cobalt n-Butyl benzenesulfonylamide Tetradecane Ferrous Iron n-Butyl-4-

methylbenzenesulfonylamide Pentadecane

Total Manganese 1st Peak in Fyrol PCF Hexadecane Molybdenum 2,6-bis(1,1-dimethylethyl)-4-

methyl phenol Heptadecane

Nickel C3 alkyl benzenes Octadecane Selenium C4 alkyl benzenes Nonadecane Tin C5 alkyl benzenes Eicosane C2 alkyl naphthalenes Heneicosane Polynuclear aromatic hydrocarbons

C3 alkyl naphthalenes Docosane

Napthalene C4 alkyl naphthalenes Tricosane Acenaphylene C2 alkyl phenanthrenes Tetracosane Acenaphthene C3 alkyl phenanthrenes Pentacosane Acenaphthalene C4 alkyl phenanthrenes Hexacosane Fluorene Heptacosane Phenanthrene Total Petroleum Hydrocarbons Octacosane Anthracene C6 - C9 fraction Acrlyonitrile Fluoranthene C10 - C14 fraction Formaldehyde Pyrene C15 - C28 fraction EDTA Benzo (a) anthracene C29 - C36 fraction Chrysene Total C6 - C36 Benzo (b) fluoranthene Benzo (k) fluoranthene Organotin Compounds Benzo (a) pyrene Monobutyltin (soluble)* 3-Methyl cholanthrene Dibutyltin (soluble)* Indeno (123cd) pyrene Tributyltin Soluble)* Dibenzo (ah) anthracene Tripropyltin (soluble) Benzo (ghi) perylene low mol weight PAHs Toxic Substances high mol weight PAHs aniline Total PAHs benzyl alcohol 4-chloroaniline Phthalates dibenzofuran Dimethyl phthalate 1-methylnaphthalene Diethyl phthalate 2-methylnaphthalene Di-n-butyl phthalate 2-nitroaniline Di-n-octyl phthalate 3-nitroaniline Butyl benzyl phthalate 4-nitroaniline Bis(2-ethylhexyl) phthalate Bisphenol A Dinonylphthalate

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6.0 HYDROGEOLOGICAL CONCEPTUAL MODEL

6.1 Regional Geological and Hydrogeological Setting

The site is located near the edge of the gently undulating Newer Volcanic lava plain with the hills of the Upper Devonian granodiorite and Silurian sediments to the north. The main stratigraphic and geomorphologic features in the broader area of the site are:

i) Silurian age bedrock consisting of shale and siltstone sediments that have been folded, faulted and intruded by Devonian age granodiorite, which outcrops at Mt. Gellibrand to the north east of the site.

ii) A broad paleo-valley developed in the Silurian bedrock running in a south-easterly direction. Over geological time the paleo valley was filled by Cainozoic age basalt flows (Older and Newer Vocanics) and variety of Tertiary age inter-flow fluvial and lacustrine sediments (Werribee Formation and Brigthon Group sediments). The centre of this regional paleo valley is located to the south west of the current Moonee Ponds Creek valley. Available drilling data indicate two erosion valleys running from the northern hills across the site towards the centre of the regional paleo-valley in the south. A low hill, now the middle of the site, separated these erosion valleys.

iii) The existing Moonee Ponds Creek valley that was cut by the current creek along the north-eastern margin of the basalt plain. Recent alluvial sediments of limited extent have been deposited along this valley.

Table 12 provides a summary of the regional stratigraphy with youngest units at the top.

Table 12. Aquifer Units at Tullamarine

Geological Age Unit Description

Recent Alluvium Silty and clayey sediments Quaternary Newer Volcanics Olivine basalt, variably weathered and

fractured

Brighton Group Variable sands and clays with medium to coarse sands in upper portion

Older Volcanics Olivine basalt, slightly to extremely weathered Tertiary

Werribee Formation Fluvial quartz sand, minor gavels, silty clays, clayey and ligneous silt

Devonian - Granodiorite, acid intrusive, fresh to extremely weathered

Silurian Dargile Formation Interbedded shales and siltstone, folded, fractured and variable weathered

Multiple aquifers occur in the fractured rocks of the Newer Volcanics, Tertiary Older Volcanics, Devonian granodiorite and Silurian siltstone and in the sediments of the Brighton Group and Werribee Formation. The aquifers are confined or unconfined depending on their stratigraphic position. Interconnection between aquifers is very complex and in some areas is not well understood.

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The regional groundwater flow direction is generally south west towards the Maribyrnong River and Port Philip Bay.

Locally discharge from aquifers occurs to the Moonee Ponds Creek and Arundel Creek.

6.2 Main Geological and Hydrogeological Units 6.2.1 General

Historical and current drilling data indicate several geological units occur at the site. Their stratigraphic relationship is shown in geological cross section in Figure 8. Locations of the sections and monitoring wells referred to in this discussion are shown in Figure 7.

6.2.2 Silurian Dargile Formation

The Silurian age sediments of the Dargile Formation, which predominantly consist of siltstone and mudstone are the oldest sediments at the site. This unit, in general, is folded, fractured and variably weathered.

The Silurian age sediments were encountered in a number of wells drilled at the site. Outcrops of the soft light yellow weathered siltstone can be observed in the bed of Moonee Ponds Creek at and down stream of the creek monitoring location MBCL08 (Figure 7). The beds of the siltstone exposed on hill slopes north of well MB11 are relatively thin (up to 30 cm) and generally dip to the north-west. The clay encountered below the Older Volcanics in some of the wells (MB7U, old well BH2) is considered to be extremely weathered Silurian siltstone.

At the site, this unit acts as a confined fractured rock aquifer where covered by younger formations. Slug tests were carried out by Golder Associates in wells MB10 and MB11 which are screened within the highly weathered siltstone zone (Golder 2001). The average hydraulic conductivity of 5.0 x 10–8 m/s and 2.5 x 10–8 m/s were indicated for well MB10 and MB11, respectively. These values are at the lower end of the hydraulic conductivity ranges reported by others in the broader Melbourne area (3.5 x 10-9 to 1 x 10-6 m/s Golder 2000). No other testing of the hydraulic properties of the Silurian age sediments are known to have been carried out at the site.

6.2.3 Quartzite/Silcrite

Outcrops of a hard, fine grained and greyish white rock are exposed in an isolated area south west of the Moonee Pons Creek monitoring point MPCL08 (south side of the creek). The rock appears to rest directly on the Silurian siltstone and dips gently to the west. The same rock, also resting on the Silurian siltstone, was encountered in wells MB14 and MB19. Previously Golder Associates (Golder 2000) interpreted this rock to presents the sands of the upper parts of the Werribee Formation or time equivalent alluvial sediments that have been altered to a very hard crystalline quartzite. A sample of the rock was sent to A.J.R. White

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Geological Services for identification. It was identified as silcrete comprised of about 98% of quartz, both as detrital grains and cement, and about 1% or less of limonite. The rock was interpreted to be sandy sediments or soil that has been leachate of minerals such as feldspars and silicified probably as a results of fluctuating groundwater. The silcrite is considered to represent the old siliceous capping developed on the Silurian palea-surface.

From its appearance in outcrop and its mineralogical description, the rock is thought to have an extremely low hydraulic conductivity in order of 1 x 10-8 m/s or less. However, if it is fractured in the subsurface, it could have a hydraulic conductivity that is significantly greater.

6.2.4 Werribee Formation

Within the northern parts of the broader Melbourne area, the Werribee Formation occurs mainly in the base of incised channels of the ancestral streams and lakes. The unit outcrops in the valley of Arundel Creek, about 3 km to the south of the Landfill (Shugg 1979). Regionally, the Werribee Formation consists of ligneous silts, sands and thin beds of well rounded quartz pebble gravels.

At the site, the Werribee Formation was encountered in the western part (wells MB5 and old wells 10002, 10003). The unit encountered in MB5LR comprises about 3.5 m thick fine to coarse sands and sandy gravels. Thickness of the Werribee Formation sands in old wells 10002 and 10003 was reported to be about 1 m (Shugg 1979). The unit encountered at the site is considered to be fluvial in origin.

The Werribee Formation is considered to act as a confined aquifer. The pumping test carried out in well 10002 (located within the old quarry hole, approximately 50 m north of L9) indicated the hydraulic conductivity of the unit of 1.5 x 10-3 m/s (Shugg 1975). Historically well 10002 (old ID Albion Reid) was used as a production well for the quarry groundwater consumption. The yield of the well was reported to be good. The old well 10003 was located about 200 m north east of well 10002. Both wells were decommissioned before the landfill advanced over this area, however, there is not information on the time and method of decommissioning.

6.2.5 Older Volcanics

The Older Volcanics, early Miocene in the age, occur as a basalt lava flow. The basalt lava overlies sediments of the Werribee Formation that occur in the western part of the site but rest directly on Silurian rock paleo-surface in the other parts of the site. The thickness of the unit at the site is generally up to 30 m.

The Older Volcanics basalt rock was quarried at the site during the quarry operation and later the landfill waste was placed directly onto this rock. The approximate outline of the top of the deep main quarry hole is shown in Figure 7. The basalt exposed in the quarry was reported to be moderately to slightly weathered and part of a single lava flow (Shugg 1975;

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Golder 1975). The joints observed at the quarry face were reported to be generally tight (Golder 1975) or infilled and welded by the secondary materials (Shugg 1975). The basalt along the shear zones that cut obliquely across the columnar joints observed in parts of basalt flow was often highly weathered partially welding the shear zones.

The top of the basalt flow was reported to be highly irregular. Drilling and test pitting for a clay borrow pit on the north side of the site (under Mound 3) indicated that the top of basalt dips steeply to the south, west and north east away from the quarry. The stiff white silty clay overlying the rock was considered to represent the in-situ weathered basalt (Golder 1981). The thickness of this clay varied across the site, with a thickness in excess of 10 m indicated in the area east and south east of the Rock Pool at the north west corner of the site. The clay in this area was excavated (clay borrow pit) and used for construction of the site clay liner.

Thick sequences of the yellow brown clay were encountered in some of the groundwater monitoring wells, especially in wells located to the west and south of the former quarry hole (MB5UR/LR, MB21/22, MB7L). Considering the drilling technique used, it may have been difficult to judge accurately the boundary between the younger Brighton Group sediments and an in-situ weathered basalt. However based on the drilling data it appears that the thickness of the extremely weathered basalt increases west and south away from the landfill. The borehole logs suggest that the basalt to the east and north east of the landfill is stronger as it is classified as moderately weathered.

The basalt of the Older Volcanics is considered to act as an unconfined to confined fractured rock aquifer. The pumping test carried out in well 10005 in 1974 indicated a hydraulic conductivity of the rock of about 4.5 x 10-7 m/s (Shugg 1975). Slightly lower basalt hydraulic conductivity of 1.0 x 10-7 m/s was reported by A.S. James in 1971 (in Shugg 1975). These data provide indication on the hydraulic conductivity of the jointed basalt rock possibly altered by the quarry activities. There is no data on the extremely weathered (clayey) parts of the rock.

6.2.6 Brighton Group

The Brighton Group sediments occur mostly in the central and eastern part of the site and overlie the Older Volcanics. The unit is thin (up to 2 m) in the central part of the site and becomes thicker (more than 15 m) to the south of the site (Figure 8).

The Brighton Group consists of variable sandy and clayey sediments. Generally medium to coarse quartz sands occur in the upper portion of the unit. At the southern and eastern part of the site the Brighton Group sand zone appears to be significantly thinner than within the western part of the site. The lower zone of the unit in this area is generally clayey. Often, while drilling the monitoring wells, it was difficult to identify a boundary between extremely weathered basalt (in-situ basalt clay) and the Brighton Group sediments. Some wells that were classified as Brighton Group wells may actually be partially screened within the clays of

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the Older Volcanics as for example well Tulla3U, which is screened within the “hard yellow grey slatey clay”1.

The unit is considered to act as an unconfined aquifer where saturated. The hydraulic conductivity is highly variable depending on lithological characteristics, being highest in the sandy zones of the unit. However, in the vicinity of the site, the groundwater table is indicated to occur predominantly within the clayey zone of the Brighton Group not the upper sandy part of the formation.

There is no known data on the hydraulic conductivity of the formation at the site. Based on Golder Associates’ experience, the Brighton Group at other sites in the Melbourne area (central and southern areas) typically has a hydraulic conductivity of around 10-6 m/s (Golder 2000). The unit at the site, however, is considered to be generated from different sources and within a different environment (fluvial erosion of the Older Volcanics and Silurian siltstone).

The unit was removed from the central parts of the site as overburden during the quarry operation. Due to an inferred high permeability of the sandy zones within the Brighton Group formation a compacted clay liner was constructed in the area where waste was placed against this unit in the landfill.

6.2.7 Newer Volcanics

The Newer Volcanics occur as a basalt lava flow. The basalt rock encountered at the site is highly to extremely weathered. Most of the unit was removed from the site during the quarry operation and landfill development. Generally there is no groundwater occurrence in the Newer Volcanics at the site and this unit is considered to be of the low hydrogeological importance.

6.3 Leachate Levels, Water Levels and Flow Direction

6.3.1 General

Groundwater levels have been monitored at the site for many years with monitoring in some wells commencing in the early 1970s. Groundwater levels have been monitored at a three monthly intervals for a number of years at 16 on-site and 2 Moonee Ponds Creek monitoring wells (Table 4) as part of the EPA Licence (EPA 2003) requirements. Groundwater levels in all Cleanaway monitoring wells (including the recently installed monitoring wells MB12 to MB24) were also recorded in October, November and December 2003 and January 2004 (Table 13). Leachate levels have been occasionally monitored in the old large diameter wells (Table 5) and monitoring wells LB1 and LB2. Since installation of the leachate extraction wells L1 to L6, L8 and L9 leachate levels have been monitored regularly in order to assess the impact of pumping on the levels within the waste.

1 From drillers log – Appendix I

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Table 13. Groundwater Levels (m AHD)

Well ID 20-Oct-03 10-Nov-03 8-Dec-03 27-Jan-04 10005 91.64 91.54 91.49 91.46 10006 90.26 90.23 90.02 89.93 97007 90.43 90.44 97005R 89.32 BH1 82.62 82.65 BH2 87.66 87.63 BH3 89.21 89.10 Tulla3L 87.02 87.04 Tulla3U 90.59 90.65 MB4LB 92.29 92.14 MB4UR 91.04 91.05 91.00 MB5LR 91.72 91.69 91.69 91.65 MB5UR 91.74 91.68 91.68 91.65 MB6L 88.46 88.41 88.32 88.20 MB6U 88.49 88.43 88.34 88.22 MB7L 91.96 91.76 91.75 91.70 MB8L 91.58 91.52 91.43 91.40 MB9L 91.16 91.12 91.09 91.06 MB10 87.53 87.50 86.94 86.74 MB11 86.27 86.22 85.89 85.67 MB12 85.76 85.74 85.35 85.24 MB13 89.67 89.64 89.55 89.57 MB14 89.62 89.57 89.49 89.51 MB15 86.19 86.08 86.09 86.14 MB16 82.94 82.72 82.87 82.89 MB17 82.96 83.02 83.05 83.11 MB18 91.48 91.42 91.36 91.35 MB19 91.59 91.54 91.52 91.45 MB20 91.77 91.53 91.50 91.43 MB21 91.40 91.24 91.23 91.17 MB22 94.62 93.65 92.56 92.11 MB23 90.08 90.07 89.93 89.92 MB24 90.78 90.86 90.73 90.84

The water level monitoring has not always been carried at the same date at all monitoring points. In order to assess groundwater flow direction and interaction with the other water bodies a co-ordinated measurements and survey of the groundwater, leachate and Moonee Ponds creek water levels was carried out on 27 January 2004. Groundwater and leachate levels were measured in all available wells, including the regional groundwater monitoring wells 97005R and 97007 and buffer zone wells BH1 to BH3 (Table 13 and Table 14). The water levels of the Moonee Ponds creek were surveyed at seven locations. The elevation of the water level within the rock pond was surveyed in January 2004. All water levels (groundwater, leachate, surface water) are shown in Figure 7. Inferred contours of the water

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table in relation to the leachate/NAPL1 levels are shown in Figure 9. Leachate levels shown in Figure 7 were obtained after the pumping system was switched off for 48 hours. The leachate levels in Figure 9 were measured on 23 January while pumping system was on. Where applicable, the leachate levels were corrected for the thickness of the NAPL present in the well. In wells L4, L5, 6 and LB2, only depth to the top of NAPL could be measured.

6.3.2 Leachate Levels

The leachate levels measured on 27 January 2004 (pumping system off) indicate significant variation across the site (Table 14). The lowest leachate level at RL 91.02 m AHD was recorded in well L6 located close to the northern face of the original quarry hole (central part - Figure 7). With the exception of the extraction well L1, well LB2 and large diameter wells 6, 8 and 15, the leachate/NAPL levels in the other wells across the landfill generally ranged from RL 91.44 m AHD to RL 92.66 m AHD. The leachate/NAPL levels in wells L1, LB2, 6 and 8 were significantly higher at levels ranging from RL 95.24 m AHD in L1 to RL 102.53 m AHD in well 6. Based on the shallow depth of wells 6 and 8 and the long screen installed in LB2, it is possible that leachate/NAPL levels recorded in these wells are representative of the perched leachate/NAPL compartments that may have developed within the old “craters” used for disposal of liquid waste. This is also suggested by observations in well LB1 located about 20 m away from LB2. Well LB2 has been consistently reported to be dry indicating that the leachate/NAPL level at this location is likely to occur below RL 95.2 m AHD. The leachate/NAPL compartments may not be in good connection with the general leachate/NAPL table considered to have developed within the lower zone of the waste.

In general, leachate levels less than RL 92.0 m AHD were recorded in the central part of the deep quarry hole (Figure 7). Higher levels were recorded at the eastern and southern ends of the old quarry hole and in the area along the south-west face of the old quarry hole. The leachate/NAPL levels recorded in Well 15 are considered not to be reliable due to poor conditions of the well (i.e. obstructions at piping joins where the level monitoring equipment becomes snagged).

Figure 9 shows leachate levels recorded while the leachate pumping system was on. In general the leachate levels in the pumping wells were up to 0.7 m (mainly about 0.4 m) lower than while pumping system was off for 48 hours. No changes or only small changes in the leachate/NAPL levels were recorded in wells L1, 8, 11, 12 and 13.

1 NAPL – nonaqueous phase liquid

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Table 14. Leachate/NAPL levels

Leachate/NAPL levels (m AHD)

Well ID Well depth (m)

23-Jan-04 pumping on

27-Jan-04 pumping off for 48

hours L1 31.41 95.27 95.24 L2 34.11 91.55 91.97 L3 31.19 91.17 91.51 L4 31.51 91.42 91.90 L5 31.6 92.25 92.33 L6 33.41 90.32 91.02 L8 33.45 91.26 91.44 L9 30.94 91.30 91.72 LB1 25.70 95.18 95.18 LB2 26.90 97.28 99.10 WELL 11 14.70 93.57 93.57 WELL 12 16.30 92.66 92.66 WELL 13 17.40 92.48 92.48 WELL 15 29.70 WELL 17 17.70 93.60 93.60 WELL T1 25.50 Damaged WELL T2 25.70 94.86 94.86 WELL T3 23.40 93.87 93.87 WELL 6 14.90 102.18 102.53 WELL 8 20.10 96.69 96.71 All levels, except otherwise indicated, are corrected for the thickness of NAPL in the well Shaded – measurements only to the top of NAPL Underlined – no NAPL encountered in the well Italic – elevation of the well base, well dry

6.3.3 Groundwater Levels and Hydraulic Gradients

Groundwater levels observed in all groundwater monitoring wells on 27 January 2004 are shown in Figure 7. Aquifers are indicated by different colours.

In general, the highest groundwater levels were observed in the wells closest to the perimeter of the landfill. Variations in the hydraulic gradients (horizontal and vertical) appear to be significant across the site, which is to be expected considering variable hydraulic properties of the main aquifers.

An upwards vertical hydraulic gradient was indicated by wells MB4UR/4LB, MB16/17 and MB23/24A while a relatively strong downwards vertical hydraulic gradient was indicated by wells Tulla3U/3L and a slight downwards hydraulic gradient by wells MB18/19/20 and MB13/14. A vertical downwards hydraulic gradient was also indicated by the pair of wells MB21 and MB22. The groundwater levels observed in MB22 (shallower well), however, are doubtful. Since installation in October 2003, the groundwater levels in this well decreased by more than 2.5 m (from RL 94.62 m AHD in October 2003 to RL 91.90 m AHD in February

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2004). During the October – December period groundwater levels decreased by a rate of about 1 m per month. Recently the groundwater level in the well appears to be stabilising. It is likely that groundwater within the well has been affected by the surface run-off. The seepage of the surface water may be entering the well through the well annulus (visible gaps around the well grout were observed during the field inspection) or enhanced recharge in the area may be induced by the surface run-off water pounding in the storm water pit that is located about 10 m away from the well. Similarly, a groundwater mound was indicated in the well 97005R (groundwater RL of 89.32 m AHD compare to the levels of about RL 83 m AHD in the closest wells MB17 and MB18, (Figure 7). Well 97005R is a replacement well for the old well 97005 at about the same location. The historical groundwater level data obtained from the regional groundwater data base suggest that the levels observed in the old 97005 well were generally lower than levels indicated by 97005R. It is possible that groundwater levels in this well are also affected by the surface water run-off.

The inferred contours of the groundwater table shown in Figure 9 illustrate the variation in the horizontal hydraulic gradient across the site. A steep horizontal gradient is indicated in the area between wells Tulla3U, MB16 and MB15 (0.07 m/m between Tulla3U and MB16). A similar gradient (0.05 m/m) is indicated between the deep Older Volcanics wells MB4LB and Tulla3L. The gradient, however, becomes flatter along the flow path further towards MB17 (Figure 8, cross-section AA). These steep hydraulic gradients are considered to be a manifestation of variations in the hydraulic conductivity along the flow path (clayey zones within the Older Volcanics and Brighton Group aquifers).

A steep horizontal hydraulic gradient is also indicated in the area adjacent to the Moonee Ponds Creek (wells BH3, MB12, MB6U, MB10, 10006 and MB23, average 0.04 m/m).

A relatively flat gradient (Figure 9) is indicated in the area east of the site (wells MB9L, MB13, BH1 and BH2, average 0.01m/m) and south of the landfill (0.005 m/m estimated from limited data).

Wells MB5UR and MB5LR have been installed to monitor the impact to groundwater flowing to the west from the landfill. Depending on its location along the western boundary, this westerly flowing groundwater would eventually flow to the north towards Moonee Ponds Creek, or to the south in the direction of the regional groundwater flow. As such, groundwater monitoring wells were not placed further to the west.

6.3.4 Groundwater Flow Direction

Groundwater levels around the site indicate mounding of groundwater under the landfill and the potential for the groundwater flow to occur in all directions from this mound. The mounding of the groundwater is considered to be related to the formerly high leachate levels within the landfill. Although the leachate levels are indicated to be reduced by on-going pumping, which commenced in mid 2003, the leachate levels still appear to be slightly higher than the surrounding groundwater levels. Yet, the groundwater level time plots do not

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indicate any clear impact of the leachate extraction on the groundwater levels. The historical leachate and groundwater level data indicated a steep hydraulic gradient between leachate and groundwater suggesting a poor connection. Therefore, the effect of the leachate pumping may take some time to influence the surrounding groundwater levels and induce an inwards hydraulic in the westerly or southern part of the site1.

As indicated in Figure 9 and the geological cross sections (Figure 8), the groundwater table occurs within the different hydrostratigraphic units. In the area south east of the landfill (line of the wells 10005, MB4UR, Tulla3U and MB16) the water table occurs within the inferred Brighton Group aquifer. In the rest of the site and close to the perimeter of the landfill the water table occurs mainly within the basalt of the Older Volcancs. Further, north east from the site (towards the Moonee Ponds Creek) the water table shifts from the basalt aquifer to the Silurian siltstone aquifer. The real, local and tree-dimensional direction and velocity of the groundwater flow, which is important for contaminant movement, is expected to change locally as groundwater moves through different aquifers (eg intergranular, fractured) with different hydraulic properties.

In general, the Moonee Ponds Creek appears to be the main discharge point, controlling groundwater movement to the north of the site. The groundwater flow to the south and south-east of the site appears to be influenced by the regional groundwater movement, which is considered to be controlled by the regional groundwater discharge zones along the Arundel Creek, Steel Creek and Maribyrnong River (eventually Yarra River and Port Phillip Bay).

For the purposes of the site risk assessment and based on the inferred groundwater flow direction and ultimate groundwater discharge point, the site monitoring wells can broadly be classified into two groups

1. Northerly groundwater wells - monitoring groundwater ultimately flowing towards the Moonee Ponds Creek. For the purposes of the risk assessment, these wells a herein referred to as the “Northerly Flowing Groundwater”. This includes the following wells (Figure 7)

• MB23/24, 10006, MB6U/L, MB10, MB112 MB12, BH3, MB9U/L, MB13/14 and BH2

2. Southerly groundwater wells monitoring groundwater likely to be flowing towards the regional discharge zones. For the purposes of the risk assessment, these wells a herein referred to as the “Southerly Flowing Groundwater”. This includes the following wells (Figure 7):

• MB5UR/LR, MB7U/L, MB21/22, MB8U/L, MB18/19/20, 10005, MB4UR, MB4LB, Tulla3U/L, MB15, MB16/17 and BH2

1 It is considered that an inwards hydraulic gradient cannot occur in the northern part of the site as the Monnee Ponds Creek levels are lower than the levels of the landfill floor. 2 Well MB11 is located to the north of the creek and therfore is within a separate watershed.

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7.0 MOONEE PONDS CREEK

7.1 Introduction

Moonee Ponds Creek forms the northern boundary to the Tullamarine Cleanaway site and, based on the hydrogeological model discussed in section 6.0, likely receives groundwater from the site through the basalt aquifer upstream of creek monitoring point MPCL08, and through Silurian siltstone aquifer downstream of this. As discussed in section 4.1, protection of aquatic ecosystems is a beneficial use of all groundwaters in Victoria. The chemical criteria used for protection of this beneficial use are based on the classification of the aquatic ecosystem condition of the Creek in the vicinity of the site. The following sections (sections 7.2, 7.3 and 7.4) discuss the physical, biological and chemical data on the Creek in the vicinity of the site. From these data, the aquatic ecosystem condition of the Creek can be classified (section 7.6). This classification is used in section 8.3 to select the chemical criteria for the Creek.

7.2 Physical Data

Moonee Ponds Creek is a tributary one stream in the Yarra River catchment. Near to the site the Creek consists of a series of open pools connected by heavily vegetated marshy sections. Substrate consists of cobble, silt, exposed bedrock and organic matter. In the vicinity and downstream of the Cleanaway site the Creek flows towards the south-southeast through urban and industrial areas, and receives stormwater run-off from these areas. Sections of the western Creek banks opposite the site have been affected by historic quarrying and landfilling activities. The eastern banks appear largely unmodified in the vicinity of the site but are covered in exotic grasses. Quarrying activities have occurred to the east of the Creek at this location.

Immediately upstream of the site the Creek forms the eastern boundary to a clean fill landfill. Here, native red-gums and grey box woodland can be seen, although this vegetation forms a narrow linear strip along the Creek. The western banks at this location are disturbed due to the landfilling activities.

Further upstream, the Creek forms the western border to the Woodlands Historic Park. This area is reported to contain the only remnant natural vegetation in the Moonee Ponds catchment (Raadik 1999). Here the Creek contains a stable, clay/sand stream bed with natural riparian vegetation.

Downstream of the site, in the suburb of Flemington, the Creek has been highly modified through channelling and the installation concrete banks and substrate.

7.3 Biological Data

Five fish species have been reported in Moonee Ponds Creek in the vicinity of the site (Raadik 1999). Three of these are native and one is an acclimatised exotic species. All of the

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native species are migratory and are known to migrate between freshwater and estuarine sections of rivers at stages in their life cycle. The fish species recorded in the Creek are shown in Table 15.

Table 15. Native and exotic fish species recorded in Moonee Ponds Creek

Species Name Status Common Name Conservation Status Anguilla australis Native Short-finned eel Common and widespread

Galaxias maculatus Native Common galaxias / Common jollytail

Common and widespread

Pseudaphritis urvillii Native Tupong Common and widespread Carassius auratus Exotic Goldfish - Gambusia holbrooki Exotic Mosquito fish - Data from Raadik (1999)

Raadik (1999) report that the data in Table 15 are incomplete and based on two brief samples. Based on survey data from similar streams in the Yarra River system, there are potentially an additional eleven native fish species (five migratory and six non-migratory) present within the system (Raadik 1999). These are shown in Table 16, along with the conservation status.

Table 16. Native fish species potentially present in Moonee Ponds Creek

Conservation Status

Species Name Migratory / Non-migratory

Common Name DSE

advisory EPBC FFG

Prototroctes maraena Migratory Australian grayling VU VU L Galaxias brevipinnis Migratory Broad-finned galaxias - - - Galaxias truttaceus Migratory Spotted galaxias - - - Geotria australis Migratory Pouched lamprey - - - Mordiacia mordax Migratory Short-headed lamprey - - - Edelia obscura / Nannoperca obscura

Non-migratory Yarra pygmy perch NT VU L

Galaxiella pusilla Non-migratory Dwarf galaxias VU VU L Gadopsis marmoratus Non-migratory River blackfish - - - Galaxias olidus Non-migratory Mountain galaxias - - - Nannoperca australis Non-migratory Southern pygmy perch - - - Retropinna semoni Non-migratory Australian smelt - - - Data from Raadik (1999); DSE = Department of Sustainability and Environment; EPBC = Environment Protection and Biodiversity Conservation Act (1999); FFG = Flora and Fauna Guarantee Act (1988); VU = vulnerable; L = listed as threatened; NT = near threatened; “-“ no listing, common

Raadik (1999) recorded three freshwater invertebrate species in the Creek in the vicinity of the site. These were the freshwater shrimp, Paratya australiensis and the common yabby, Cheras destructor and a bivalve mollusc, the pea mussel (Corbicula australis). Diversity and abundance in the Creek was found to be lower opposite the site than at locations upstream in the Woodlands Historic Park.

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Raadik (1999) concluded that the upper Moonee Ponds Creek (in the vicinity of the site) comprised severely degraded aquatic fauna assemblage characterised by:

• very low species diversity and richness;

• an absence of any migratory native species; and

• low fish abundance.

The degraded in-stream habitat and water quality and reduced environmental flows were considered to be the major factors affecting the aquatic fauna in the area..

Data from earlier studies provide additional information. A biological study of Moonee Ponds Creek undertaken in 1998 as part of the Airport Rail Link corridor investigation by Muir and Bezuijen (1998) noted that:

• The degraded drainage-line complex of Moonee Ponds Creek contains indigenous vegetation such as red gums scattered along the Creek banks. These are considered to be of high local significance. Grey box woodland is also of high local significance, and the Creek was considered to be of regional significance.

• Creek-side vegetation, consisting of mostly exotic grasslands, provide refuge for a variety of frogs, reptiles and birds;

• The Creek itself contains tadpoles, fish, yabbies and aquatic invertebrates.

7.4 Historical Water Quality Data

The Moonee Ponds Creek catchment has been described as having the poorest water quality of any major tributary in the Yarra River catchment (Ho and Pettigrove 1996). In the 1998 Melbourne Water report on Healthy Waterways, the lower Moonee Ponds Creek was reported to have poor water quality, with high nutrient and E. coli levels (Coleman 1999). Sediments in the lower reaches1 of the Creek are reported to be of high risk to ecosystem health, with elevated concentrations of cadmium and chromium. These may be due to run-off from industrial sites and roadways, spills and discharges and leachate from landfill sites (Coleman 1999).

In 1996 water quality was sampled at three locations in the Creek: (i) within Woodlands Historic Park near Somerton Road (approximately 9 km upstream of the site), (ii) at Marker Road (approximately 1.1 km upstream of the site) and (iii) at Koala Crescent (approximately 2 km downstream of the site). The results included:

• conductivity measurements of 3300 µS/cm within Woodlands Historic Park near Somerton Road, 1800 µS/cm at Marker Road and 1500 µS/cm at Koala Crescent.

1 The location of the “lower reaches” was not specified in the report, however sediment was sampled around Broadmeadows Road Westmeadows and Moonee Boulevard, Gowanbrae. These locations are downstream of the Cleanaway Tullamarine site.

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• decreasing turbidity moving downstream, increasing slightly between Marker Road and Koala Crescent.

• Higher concentrations of heavy metals in stream sediments were noted at Marker Road (nickel), Koala Crescent (cadmium), and downstream (nickel, cadmium and mercury). Cadmium and chromium concentrations were generally higher than other urban waterways, while zinc, mercury and copper were lower. The source(s) of the high chromium concentrations were not identified (Ho and Pettigrove 1996).

7.5 Cleanaway Data

Since 1992 Cleanaway has conducted water quality monitoring at two locations in Moonee Ponds Creek. Up until 2003, these two sites were: the “Upper Creek” immediately upstream of the site and the “Lower Creek” near the boundary of the site. Data obtained for the period September 1992 to December 2003 for these sites are summarised in Table 17 and Table 18.

Historical surface water quality data from the Creek indicated neutral to slightly alkaline water with a TDS concentration ranging from 340 mg/L to 2,400 mg/L. Differences in TDS concentration and pH between Lower and Upper Creek monitoring locations were evident. The average TDS concentration at Lower Creek location during the monitoring period (1992 to 2003) was around 1,200 mg/L compared to 800 mg/L at the Upper Creek location. The observed variation in TDS may have been caused by high TDS groundwater discharging into the Creek from the north or south, or by leachate-impacted groundwater discharging into the Creek from the south.

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Table 17. Surface Water Quality – Moonee Ponds Creek “Upper” site

Upper Creek Analytes

28/9/92 22/4/93 14/7/93 26/10/93 16/4/96 9/7/96 4/1/98 1999 2000 2001 2002 2003

No. measurements 1 1 1 1 1 1 1 1 3 3 4 3 pH (pH units) 7.9 7.7 7.1 7.9 7.6 7.7 7.6 7.7 7.3-7.6 7.3-9.6 7.3-7.7 7.5-7.7 TDS (2) 580 950 1300 1000 780 380 710 950 610-1700 340-1300 750-1200 500-970 TOC (3) 54 35 61 13 12 70 11 11 10-24 7-11 7-16 5-8 Aluminium 23 0.23 0.6 0.39 6.0 19 1.2 - - - - - Cadmium <0.05 <0.05 <0.05 <0.05 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Chromium <0.05 <0.05 <0.05 <0.05 0.01 0.04 <0.01 <0.01 <0.01-0.07 <0.01 <0.01 <0.01 Copper <0.05 <0.05 <0.05 <0.05 0.03 0.02 <0.01 <0.01 <0.01-0.03 <0.01 <0.01 <0.01 Iron 16 0.29 1.2 1.4 6.0 20 1.2 1.2 <0.05-2.4 0.06-0.65 <0.05-0.39 0.15-1.5 Lead <0.05 <0.05 <0.05 <0.05 0.02 <0.01 <0.01 <0.01 <0.01-0.02 <0.01 <0.01 <0.01 Mercury <0.1 <0.1 <0.1 <0.1 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Zinc 0.06 <0.05 0.09 <0.05 0.12 0.06 0.02 0.02 <0.01-0.04 <0.01-0.12 <0.01-0.03 <0.01-0.01

Total Chlorinated Hydrocarbon

<0.1 <0.1 <0.1 <0.3 <0.01 <0.05 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

TDS = total dissolved solids; TOC = total organic carbon

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Table 18. Surface Water Quality – Moonee Ponds Creek “Lower” site

Lower Creek Analytes

28/9/92 22/4/93 14/7/93 26/10/93 16/4/96 9/7/96 4/1/98 1999 2000 2001 2002 2003

Number of Analyses 1 1 1 1 1 1 1 1 3 3 4 3 pH (pH units) 7.8 7.9 7.3 8.0 7.9 7.7 7.9 7.4-7.6 7.4-7.6 7.3-8.0 7.6-7.9 TDS 620 1300 1400 1400 990 390 1200 840 710-1900 550-2400 930-1700 730-1700 TOC 56 40 50 11 11 70 15 9 12-24 10-15 7-15 6-12 Aluminium 23 0.09 0.65 0.24 4.4 17 0.23 - - - - - Cadmium <0.05 <0.05 <0.05 <0.05 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Chromium <0.05 <0.05 <0.05 <0.05 0.07 0.04 <0.01 0.23 <0.01-0.07 <0.01 <0.01 <0.01 Copper <0.05 <0.05 <0.05 <0.05 0.03 0.02 <0.01 0.01 <0.01-0.03 <0.01-0.002 <0.01 <0.01 Iron 15 0.14 0.6 1.2 4.6 18 0.29 0.94 <0.05-2.6 0.11-0.7 <0.05-0.44 0.52-0.95 Lead <0.05 <0.05 <0.05 <0.05 <0.01 <0.01 <0.01 <0.01 <0.01-0.03 <0.01-0.002 <0.01 <0.01 Mercury <0.1 <0.1 <0.1 <0.1 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 Zinc <0.05 <0.05 0.05 <0.05 0.04 0.07 0.02 <0.01 <0.01-0.07 <0.01-0.71 <0.01-0.02 <0.01-0.02 Total Chlorinated Hydrocarbon

<0.1 <0.1 <0.1 <0.3 <0.01 <0.05 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

TDS = total dissolved solids; TOC = total organic carbon

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7.6 Summary of Aquatic Ecosystem Condition of the Creek

The Australian and New Zealand Guidelines for Fresh and Marine Water Quality (“the Guidelines”, ANZECC and ARMCANZ 2000) provide a framework for assigning different levels of protection for different conditions of aquatic ecosystems. Three ecosystem conditions are recognised in the guidelines. These are:

• High conservation/ecological value systems. These are effectively unmodified or other highly valued ecosystems, typically (but not always) occurring in national parks, conservation reserves or in remote and/or inaccessible locations

• Slightly to moderately disturbed systems, which are ecosystems in which aquatic biological diversity may have been adversely affected to a relatively small but measurable degree by human activity. The biological communities remain in a health condition and ecosystem integrity is largely retained.

• Highly disturbed systems, which are measurably degraded ecosystems of lower ecological value. Examples of highly disturbed systems would be urban streams receiving road and stormwater run-off, or rural streams receiving runoff from intensive horticulture (ANZECC and ARMCANZ 2000).

In the vicinity of the site, Moonee Ponds Creek would be considered to be a modified environment, with reduced water quality, biological communities and environmental flows, but with sections supporting native vegetation and natural aquatic ecosystems. Downstream of the site at Flemington, where channelling has occurred, the Creek would be considered to be a highly disturbed system. At locations upstream of the site, and particularly in the Woodlands Historic Park, the Creek may be considered to have high conservation value.

The ANZECC and ARMCANZ (2000) guidelines provide different water quality criteria for the different ecosystem conditions. That is, ecosystems of higher value require a higher level of protection, and therefore have lower, more stringent, water quality criteria. Criteria that would apply to the Moonee Ponds Creek in the vicinity of the site area are considered to be those that apply to “slightly to moderately disturbed ecosystems”. These are listed in section 8.3.

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8.0 GROUNDWATER, SURFACE WATER AND SEDIMENT CRITERIA

8.1 Groundwater Use in Area

A search of the Department of Sustainability and Environment (DSE) database established that there are 38 registered groundwater wells within a two kilometer radius of the site. A list of the groundwater bores with their co-ordinates and bore use is presented in Appendix I.

The known uses of the wells are for investigation or groundwater observation purposes. Most of them are located at the Tullamarine Waste Disposal site.

Groundwater usage in the area is low. This is likely due to the poor quality of the aquifers, which generally have a high total dissolved solids (TDS) concentration, especially in the upper aquifers.

8.2 Groundwater Quality and Beneficial Uses

There are limited data on background conditions for groundwater at the site and groundwater quality of the regional aquifers.

Only a few groundwater monitoring wells were drilled at the site before waste disposal began in May 1972. Shugg (1994) reported that four groundwater monitoring wells were sampled and analysed for TDS concentration prior to this time. The TDS concentration was reported to range from 760 mg/L to 3,000 mg/L. Data are summarised in Table 19.

Table 19. Background TDS of Groundwater

Bore ID - old Aquifer type Year of Sampling Total Dissolved Solids

(mg/L) 10001 Older Volcanics February 1972 7601 10002 Werribee Formation February 1972 1,858 10003 Werribee Formation February 1972 2,371 10005 Older Volcanics September 1973 2,500 10006 Older Volcanics/Silurian September 1974 2,400 Tulla3L Older Volcanics/Silurian Early 1973 2,500 Tulla3U Brighton Group October 1971 3,000 Data from Shugg (1994); Golder (1975) Well location 10001 was located on site in the south east corner of the landfill, approximately 100 metres to the west of well 10005.

The observation bore Tulla3L, which is located about 200 m south east of the landfill, was installed in the Older Volcanics/Silurian siltstone in October 1972 after waste disposal commenced. However, as discussed in the Golder Associates Report No 94612119 (Golder 1994), the concentration of TDS as well as other parameters did not fluctuate significantly during the initial period October 1972 to October 1974. Therefore, the observed groundwater chemistry at that time was likely to be representative of conditions existing before waste

1 Initial result (one measurement). Subsequent data summarised in Golder (1975) showed average TDS of bore 10003 to be approximately 2,000 mg/L in 1972.

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disposal commenced. The average TDS concentration in groundwater observed in this period was 2,300 mg/L.

There are no data on background quality of groundwater in the Silurian aquifer as there were no monitoring wells that had been installed in the Silurian aquifer prior to commencement of landfilling. The TDS concentrations of groundwater at monitoring bore MB7L, which is inferred to monitor Silurian aquifer mainly, ranged from 960 mg/L to 1,100 mg/L and remained relatively constant during the 1999-2000 monitoring period. For wells MB11, MB14 and MB24, the TDS concentrations range from 3,000 mg/L to 3,700 mg/L.

Based on estimated TDS concentrations, under the SEPP Groundwaters of Victoria (GoV 1997), the background groundwater quality in all aquifers under the site would likely be classified as Segment B (TDS range 1,001 mg/L to 3,500 mg/L, refer section 4.1).

The range of beneficial uses to be protected for Segment B groundwater are as follows (GoV 1997):

• maintenance of ecosystems;

• potable mineral water supply;

• agriculture, parks and gardens (irrigation);

• stock watering;

• industrial water use;

• primary contact recreation such as bathing and swimming; and

• buildings and structures.

The Groundwater SEPP (GoV 1997) specifies that all the listed beneficial uses for a Segment must be protected. Therefore, the initial assessment of potential groundwater impact must take into account all of the beneficial uses listed above. For the purposes of this assessment, it has been assumed that the majority of the groundwater in the north of the site will discharge into the Moonee Ponds Creek, which is considered to be a freshwater system at this location.

Potable mineral water beneficial use of the groundwater is not possible in the area of the site because it does not meet the definition of mineral water1 as per the SEPP (GoV 1997).

8.3 Ground- and Surface Water Assessment Criteria

The Groundwaters of Victoria SEPP cites references in which criteria are nominated for particular protected beneficial uses. The relevant criteria for the protected beneficial uses for the on-site and offsite groundwater are described or referenced in the SEPP. For raw drinking

1 Mineral Water in Victoria is defined as “groundwater which in its natural state contains carbon dioxide and other soluble matter in sufficient quantities to cause effervescence or impart a distinctive taste” (GoV 1997) .

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water, irrigation, stockwater, industrial water use and primary contact recreation, the Groundwaters of Victoria SEPP refers to the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC 1992). For the protected beneficial use of “maintenance of ecosystems”, the Groundwater SEPP refers to “the relevant State Environment Protection Policy for surface waters”. As discussed in section 4.2, Moonee Ponds Creek is part of the Yarra Catchment, which is regulated under Schedule F7 of the Waters of Victoria SEPP (GoV 2003). Some criteria for protection of aquatic ecosystems are provided in Schedule F7, but criteria for toxicants are listed in the ANZECC and ARMCANZ (2000) Australian and New Zealand Guidelines for Fresh and Marine Waters.

The groundwater criteria have been divided into two categories. Those associated with maintenance of ecosystems, which are relevant at the point of discharge of the groundwater, and those uses grouped as groundwater extractive uses, which are relevant at the point the groundwater is extracted from the aquifer. Groundwater extraction could occur either on-site or off-site. Criteria for maintenance of aquatic ecosystems are those listed in ANZECC and ARMCANZ (2000) Guidelines for “slightly to moderately disturbed” systems. The adopted groundwater assessment criteria are summarised in Table 20.

Table 20. Groundwater and Surface Water Assessment Criteria

Maintenance of Ecosystems

(mg/L)1 Groundwater Extractive Use Criteria (mg/L)

Analytical Schedule Aquatic

(Freshwater)1,2

Ecosystems

Recreational Water/

Drinking Water,3,4

Irrigation3 Stock

Watering3

SCHEDULE A Anions/cations etc. Sodium 300 Calcium 1000 Chloride 400 Fluoride 2 Nitrate as N 0.16 10 30 Sulphate as SO4 2- 400 3000 2700 Total Dissolved Solids (TDS) 1000A Total Hardness 500 pH (pH units) 6.0-8.5B 6.5-8.5 4.5-9 6-8.5 Anionic Surfactants(as MBAS) 0.14 0.2 Non-Metallic Inorganics Cyanide 0.007 0.1 Ammonia as N5 0.9 0.01 Metals Arsenic 0.013 0.05 0.1 0.5 Cadmium 0.0002 0.005 0.01 0.01 Chromium Total 0.05 1 1 Chromium (VI) 0.001 Copper 0.0014 1 0.2 0.5 Total iron 0.3 1 Lead 0.0034 0.05 0.2 0.1 Mercury 0.00006 0.001 0.002 0.002 Zinc 0.008 5 2 20

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Table 20. Groundwater and Surface Water Assessment Criteria contd.



Analytical Schedule Aquatic (Freshwater)1,2

Ecosystems

Recreational Water/

Drinking Water,3,4

Irrigation3 Stock

Watering3

Chlorinated Hydrocarbons Hexachlorobenzene 0.0001 Hexachlorobutadine 0.00004 Hexachlorocyclopentadene 0.00005 Hexachloroethane 0.29 Pentachlorobenzene 0.002 1,2,4,5-tetrachlorobenzene 0.007 1,2,4-trichlorobenzene 0.085 1,2,3-trichlorobenzene 0.003 Chlorobenzene 0.055 0.3 1,4-dichlorobenzene 0.06 0.04 1,3-dichlorobenzene 0.26 1,2-dichlorobenzene 0.16 1.5 Phenols Total Phenol 0.32 0.002 2-chlorophenol 0.34 0.3 4-chlorophenol 0.22 2,3-dichlorophenol 0.031 2,4-dichlorophenol 0.12 0.2 2,6-dichlorophenol 0.034 2,4,6-trichlorophenol 0.003 0.01 2,3,4,6-tetrachlorophenol 0.01 0.001 pentachlorophenol 0.0036 0.01 2,4-dimethylphenol 0.002 2-methyl-4,6-dinitrophenol 2-nitrophenol 0.002 4-nitrophenol 0.058 2,4-dinitrophenol 0.045 2,4,6-trinitrophenyl 0.25 Polychlorinated Biphenyls Aroclor 1016 0.000001 Aroclor 1221 0.001 Aroclor 1232 0.0003 Aroclor 1242 0.0003 Aroclor 1248 0.00003 Aroclor 1254 0.00001 Total PCBs 0.0001 SCHEDULE B Aluminium 0.055 0.2 5 5 Barium 1 0.1 Boron 0.37 1 0.5 5 Chromium (III) 0.0033 0.05 Cobalt 0.0014 0.05 1 Total Manganese 1.9 0.1 2 Molybdenum 0.034 0.05 0.01 0.01 Nickel 0.011 0.1 0.2 1 Selenium 0.005 0.01 0.02 0.02 Silver 0.00005 0.05 Tin 0.003

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Table 20. Groundwater and Surface Water Assessment Criteria contd.



Analytical Schedule Aquatic (Freshwater)1,2

Ecosystems

Recreational Water/

Drinking Water,3,4

Irrigation3 Stock

Watering3

Polynuclear aromatic hydrocarbons Napthalene 0.016 Phenanthrene 0.002 Anthracene 0.00001 Fluoranthene 0.0014 Benzo (a) pyrene 0.0002 0.00001 0.00001 Phthalates Dimethyl phthalate 3.7 Diethyl phthalate 1.0 Di-n-butyl phthalate 0.035 Bis(2-ethylhexyl) phthalate 0.001 Volatile Organic Compounds Vinyl Chloride 0.1 1,1-Dichloroethene 0.7 0.0003 1,1-Dichloroethane 0.09 Dichloromethane 4 0.004 Chloroform 0.37 1,1,1-trichloroethane 0.27 1,2 -dichloroethane 1.9 0.01 Carbon tetrachloride 0.24 0.003 Benzene 0.95 0.01 Trichloroethylene 0.33 1,2-dichlorpropane 0.9 1,3-dichloropropene 0.1 Toluene 0.18 0.8 1,1,2-trichloroethane 6.5 1,3-dichloropropane 1.1 Tetrachloroethylene 0.07 0.05 Ethyl benzene 0.08 0.3 m-xylene 0.075 o-xylene 0.35 p-xylene 0.2 1,1,2,2-tetrachloroethane 0.4 Isopropylbenzene 0.03 Carbon disulfide 0.02 Organotin Compounds Tributyltin Soluble)* 2.0 Toxic Substances Toxic Substances Aniline 0.008

Notes: 1. Based on the ANZECC 2000 Australian Water Quality Guidelines for Fresh and Marine Waters. 2. Trigger values that apply to typical slightly to moderately disturbed systems. Trigger values in italics are low reliability values 3. Based on the ANZECC 1992 Australian Water Quality Guidelines for Fresh and Marine Waters Drinking Water criteria. Criteria were multiplied by a factor of ten for use as recreational water criteria (refer section 8.3). 4. Based on Australian Drinking Water Guidelines 1996. Criteria can be multiplied by a factor of ten for use as recreational water criteria (refer section 8.3). 5. Ammonia as total ammonia as (NH3-N) at pH 8. A. Variation of the State Environment Protection Policy (Waters of Victoria), insertion of Schedule F7, Waters of the Yarra Catchment.

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As discussed in correspondence with Cleanaway and EPA Victoria (Golder 2003; EPA 2003b), not every parameter listed in the analytical Schedules A and B has a defined criterion. However, for most groups of chemicals, one or more of the parameters do have criteria and in general, the more toxic chemicals (based on current science) have the most information available and hence are most likely to have a criterion designated.

For parameters without specified criteria, detection limits were interpreted as appropriate screening criteria, particularly if the lowest practical detection limits were used. For the purposes of this risk assessment, chemicals that will be considered in the next phase of the risk assessment are those that are found to be at a concentration:

• above the criterion for the specified beneficial use; or

• above the detection limit, where no criterion is available.

The recreational water criteria shown in Table 20 are based on the drinking water guidelines (ANZECC 1992). It is noted that ANZECC (1992) state that for toxic chemicals:

“In general, toxic substances [in recreational waters] should not exceed the concentrations given for untreated drinking waters….Higher concentrations of toxicants may be tolerated occasionally if it is assumed that a person will ingest a maximum of 100 mL water during a normal swimming session…compared with 2 L/d for potable water.” (ANZECC 1992)

On this basis, chemicals that were found to exceed the recreational water (drinking water) criteria were also compared with ten-times the recreational water criteria. The ten-fold multiplier is conservative, given that the drinking water ingestion to swimming water ingestion ratio estimated by ANZECC (1992) is twenty-fold.

Hence, chemicals that were found to be in concentrations in excess of the recreational water criteria were only considered to be of interest if they also exceeded ten-times the recreational water criteria.

8.4 Sediment Criteria

Neither Schedule F7 of the Waters of Victoria SEPP (which covers surface waters within the Yarra River catchment) nor the Waters of Victoria SEPP itself (which covers Victoria’s surface water environment) provide specific guidance on the protection and assessment of aquatic sediments. Specific Victorian regulations and/or legislation do not currently exist for protection of aquatic sediments (except in the case of dredging) and the criteria that apply for assessment. However, the ANZECC and ARMCANZ (2000) guidelines provide a decision tree for the assessment of contaminated sediment, and criteria (sediment quality guidelines) to assess for potential effects of contaminated sediment on aquatic biota.

The sediment quality guidelines in ANZECC and ARMCANZ (2000) are based on overseas data (Long et al. 1995) because there are few reliable data on sediment toxicity for either Australian or New Zealand conditions. Hence, the sediment guidelines are interim trigger

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values (interim sediment quality guidelines, ISQGs), which, if exceeded, are designed to “trigger” either management action or additional site-specific studies. Both ISQG-low and ISQG-high are provided in the Guidelines. These categories correspond to probability of effects in exposed organisms. Sediment concentrations of contaminants below the ISQG-low are considered to have a low probability of causing deleterious effects on benthic organisms. Sediment concentrations of contaminants above the ISQG-high are considered to have a high probability of causing deleterious effects on benthic organisms, but should trigger further assessment and/or management. Sediment concentrations of contamination between the ISQG-low and ISQG-high would trigger further assessment and/or management.

For the purposes of this preliminary risk assessment, the ISQG-low have been used to screen the sediments. Measured concentrations of contaminants below the ISQG-low are considered to pose low risk and are therefore not considered further. Measured concentrations of contaminants above the ISQG-low and/or above the ISQG-high are considered in the context of background (upstream) sediment concentrations, as well as other factors.

The list of ISQG-low and ISQG-high are shown in Table 21.

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Table 21. Sediment Assessment Criteria

Contaminant ISQG-low ISQG-high

Metals (mg/kg dry weight) Antimony 2 25 Cadmium 1.5 10 Chromium 80 370 Copper 65 270 Lead 50 220 Mercury 0.15 1 Nickel 21 52 Silver 1 3.7 Zinc 200 410 Metalloids (mg/kg dry weight) Arsenic 20 70 Organometallics Tributyltin (µg Sn/kg dry weight) 5 70

Organics (µg/kg dry weight) Acenaphthene 16 500 Acenaphthalene 44 640 Anthracene 85 1100 Fluorene 19 540 Naphthalene 160 2100 Phenanthrene 240 1500 Low molecular weight PAHs 552 3160 Benzo(a)anthracene 261 1600 Benzo(a)pyrene 430 1600 Dibenzo(a,h)anthracene 63 260 Chrysene 384 2800 Fluoranthene 600 5100 Pyrene 665 2600 High molecular weight PAHs 1700 9600 Total PAHs 4000 45000 Total DDT 1.6 46 p,p’-DDE 2.2 27 o,p’- +p,p’-DDD 2 20 Chlordane 0.5 6 Dieldrin 0.02 8 Endrin 0.02 8 Lindane 0.32 1 Total PCBs 23 -

Data from ANZECC and ARMCANZ (2000) A. Low molecular weight PAHs are the sum of concentrations of acenaphthene, acenaphthalene, anthracene, fluorene, 2-methylnapthalene, naphthalene and phenanthrene. High molecular weight PAHs are the sum of concentrations of benzo(a)anthracene,benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene and pyrene

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8.5 Use of Criteria The criteria listed in Table 20 and Table 21 are deliberately set to be conservatively low so that they can be applied across many sites and across different receptors (e.g., children and adults). This conservatism means that chemicals found at concentrations below their respective criteria are considered to pose negligible risks to the relevant receptors via the pathway indicated. Conversely, chemicals with concentrations above their respective criteria may pose risks to the relevant receptors, although this is not certain. Therefore, chemicals with measured concentrations above criteria should be further assessed for their potential to pose risks.

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9.0 CHEMICAL SCREENING OF GROUNDWATER (AQUEOUS PHASE)

The following sections provide an assessment of the aqueous chemical data collected from each groundwater well in October and December 2003. The assessment has divided the groundwater into that flowing in a southerly direction (section 9.1) and that flowing in a northerly direction (section 9.2). Within each flow direction section, the groundwater has been further divided by aquifer, such that the Brighton Group, Older Volcanics, Werribee Formation and Silurian are assessed in the southerly-flowing groundwater, and the Older Volcanics and Silurian are assessed in the northerly flowing groundwater.

The objectives of this section are to identify those chemicals which are of interest and hence should be carried forward for further evaluation in this risk assessment. To achieve this, the measured chemical data within each aquifer was compared with criteria (where available) and detection limits (where no criteria were available). When all measured concentrations of a particular chemical were found to be below all relevant criteria or detection limits, the chemical was not identified as a chemical of interest, and was therefore not retained for the supplementary risk assessment. When chemical concentrations were above criteria or detection limits (where no criteria were available), the chemical was retained as a chemical of interest for further assessment.

This approach is consistent with the intent of the criteria. As discussed in section 8.5, chemical criteria are set conservatively low so that they can be applied across different sites and receptor types (e.g., adults and children). Therefore, concentrations of chemicals below their respective criteria are considered to pose negligible risks, and need not be considered further. Concentrations of chemicals above their respective criteria may pose potential risks and therefore should be further assessed.

The groundwater data used for the chemical screening was that collected in October and December 2003 by Kingtech (refer to Appendix H for copies of field sampling records). Laboratory analyses were undertaken by AGAL, Leeder Consulting and WSL Consultants. Copies of laboratory reports are contained in Appendix F. Summary tables are in Appendix D.

9.1 Groundwater Flowing in a Southerly Direction

Groundwater wells MB15, Tulla3U, MB4UR, MB16, 10005, Tulla3L, MB4LB, MB5UR, MB7L, MB8L, MB17, MB20, MB21, MB22, MB5LR, MB19 and MB18 were considered to be screened in groundwater with a southerly flow direction (refer section 6.0). These wells were then divided by aquifer into wells screened in the Brighton Group (wells MB15, Tulla3U, MB4UR and MB16), wells screened in the Older Volcanics / Silurian siltstone (wells 10005, Tulla3L, MB4LB, MB5UR, MB7L, MB8L, MB17, MB20, MB21 and MB22), wells screened in the Werribee Formation (well MB5LR) and wells screened in Silcrete / Silurian siltstone (wells MB19 and MB18).

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The following sections describe the chemicals that exceed the beneficial use criteria in each aquifer. Summary tables are provided in the text.

9.1.1 Brighton Group Groundwater

The concentrations of chemicals found in each well in the southerly flowing Brighton Group groundwater were compared with the beneficial use criteria for aquatic ecosystem protection, recreational1 waters, irrigation and stock-water. Table 22 provides the detailed screening of the southerly flowing Brighton Group groundwater, and shows the locations, by wells, of the beneficial use criteria exceedences. This table also provides a brief reasoning as to whether the chemical is carried through as a chemical of interest for further assessment.

Table 23 summarises the identified “chemicals of interest” as well as the beneficial use criteria (or in some cases the detection limit) that were exceeded in the southerly flowing Brighton Group groundwater.

1 The recreational water criteria for toxicants are taken from the guidelines for raw waters for drinking purposes (ANZECC 1992), supplemented by the Australian Drinking Water Guidelines (NHMRC 1996), where possible. As the guidelines are based on drinking water, comparison of the measured concentrations with ten-times the criteria was made (refer section 8.3).

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Table 22. Details of Chemical Screening for Southerly Flowing Brighton Group Groundwater

Chemical Exceedence Well(s)

October 2003 concentration

(mg/L)

December 2003 concentration

(mg/L) Criteria (mg/L) Comment

MB15 9,300 10,000 Tulla3U 8,800 8,900 MB4UR 10,000 9,900 TDS

MB16 13,000 13,000

3,500 (ABU) Retained as a chemical of interest on the basis of ABU criteria exceedence.

Tulla3U 0.57 0.69 Nitrate (as N) MB4UR 1.2 1.5 0.16 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Anionic surfactanats MB16 <0.01 3.2 0.14 (AEP) 0.2 (RW)

Retained as a chemical of interest on the basis of AEP and 10-times RW criteria exceedences.

MB15 0.006 0.005 MB4UR 0.01 <0.01 Copper MB16 0.02 <0.02

0.0014 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB15 <0.05 2.2 Tulla3U 0.64 0.27 Iron MB4UR 0.87 0.38

0.3 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest.

MB4UR <0.01 0.022 Zinc MB16 0.072 <0.05 0.008 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Barium MB16 NA 0.8 0.1 (I) Retained as a chemical of interest on the basis of I criteria exceedence. MB15 NA 0.005 Cobalt MB16 NA 0.007 0.0014 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Total manganese MB15 NA 0.45 0.1 (RW) 0.2 (I)

Retained as a chemical of interest on the basis of I criteria exceedence only. Concentrations not greater than 10-times RW criteria.

MB15 NA 0.035 Nickel MB16 NA 0.02 0.011 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB15 NA 0.02 Selenium MB16 NA 0.024 0.005 (AEP) 0.01 (RW)

Retained as a chemical of interest on the basis of AEP criteria exceedence only. Concentrations not greater than 10-times RW criteria.

Aroclor 1254 MB15 <0.000001 0.000018 0.00001 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. MB15 NA 4.4 x 10-6 Acenaphthylene MB16 NA 2.4 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 1.4 x 10-6 Acenaphthene MB16 NA 1.4 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 5.1 x 10-6 Fluorene MB16 NA 3.9 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 2.1 x 10-4 Pyrene MB16 NA 1.8 x 10-4 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 5.4 x 10-6 Benzo(a)anthracene MB16 NA 9.6 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

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Table 22. Details of Chemical Screening for Southerly Flowing Brighton Group Groundwater contd.



(mg/L)



MB15 NA 4.7 x 10-6 Chrysene MB16 NA 1.0 x 10-4 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 2.9 x 10-6 Benzo(b)fluoranthene MB16 NA 6.7 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 3.1 x 10-6 Benzo(k)fluoranthene MB16 NA 7.2 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 1.2 x 10-6 Indeno(1,2,3cd)pyrene MB16 NA 3.4 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 1.0 x 10-6 Benzo(g,h,i)perylene MB16 NA 3.9 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB15 NA 0.005 Bis(2-ethylhexyl)phthalate MB16 NA 0.003 0.001 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Acetone MB16 0.039 <0.01 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. MB15 NA 64 Tripropyltin MB16 NA 41 2 (DL) Retained as a chemical of interest because detectable concentrations present.

ABU = any beneficial use; AEP = aquatic ecosystem protection; RW = recreational water; I = irrigation water; DL = detection limit; NA = not analysed

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Table 23. Chemicals of Interest – Southerly Flowing Brighton Group Groundwater

Exceedence by Beneficial Use Criteria or Detection Limit

Chemical Aquatic

Ecosystem Protection

Recreational Water Irrigation Stock water Detection

Limit

TDS Nitrate (as N) Anionic surfactants Copper Zinc Barium Cobalt Total manganese Nickel Selenium Aroclor 1254 Acenaphthylene Acenaphthene Fluorene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Indeno(1,2,3cd)pyrene Benzo(g,h,i)perylene Bis(2-ethylhexyl)phthalate

Acetone Tripropyltin

9.1.2 Older Volcanics Groundwater

The concentrations of chemicals found in each well in the southerly flowing Older Volcanics groundwater were compared with the beneficial use criteria for aquatic ecosystem protection, recreational1 waters, irrigation and stock-water. Table 24 provides the detailed screening of the southerly flowing Older Volcanics groundwater, and shows the locations, by wells, of the beneficial use criteria exceedences. This table also provides a brief reasoning as to whether the chemical is carried through as a chemical of interest for further assessment.

Table 25 summarises the chemicals of interest as well as the beneficial use criteria (or in some cases the detection limit) that were exceeded in the southerly flowing Older Volcanics groundwater.


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Table 24. Details of Chemical Screening for Southerly Flowing Older Volcanics Groundwater



(mg/L)



10005 6,900 6,500 MB4LB 6,900 6,800 MB5UR 5,600 5,800 MB8L 14,000 15,000 MB17 3,700 3,800 MB20 7,600 8,500

TDS

MB22 2,400 4,000

3,500 (ABU) Retained as a chemical of interest on the basis of ABU criteria.

MB5UR 0.47 0.49 Nitrate (as N) MB8L 0.17 <0.01 0.16 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

10005 0.17 0.15 MB8L 1.2 0.43 MB20 1.7 2.5 Anionic surfactants

MB22 <0.1 0.4

0.14 (AEP) 0.2 (RW)

Retained as a chemical of interest on the basis of AEP and 10-times RW criteria exceedences.

MB5UR <0.01 0.022 Cyanide MB8L <0.01 0.01 0.007 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Tulla3L 0.1 <0.1 MB4LB 0.1 0.1 Ammonia (as N) MB8L 0.2 0.2

0.01 (RW) Retained as a chemical of interest on the basis of 10-times RW criteria exceedence.

MB8L 0.012 <0.01 Chromium total MB20 0.017 0.006 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. No Cr(VI) detected, but detection limit in MB20 exceeds criteria.

MB17 0.002 0.001 MB20 0.008 0.003 MB21 0.003 0.003 Copper

MB22 0.003 0.003


10005 1.9 1.3 Tulla3L 0.43 0.43 MB4LR 4.4 3.7 MB5UR 0.61 0.4 MB8L 9.1 3.4 MB17 0.28 0.46 MB20 3.8 3.5 MB21 <0.05 0.31

Iron

MB22 <0.05 1.1

0.3 (RW) Some concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of 10-times RW criteria exceedence.

MB20 0.0054 0.010/0.00086* Mercury MB21 <0.00005 0.006/0.00007* 0.00006 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

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Table 24. Details of Chemical Screening for Southerly Flowing Older Volcanics Groundwater contd.



(mg/L)



MB8L 0.025 <0.01 MB17 0.06 <0.005 MB20 0.022 0.061 MB21 0.02 0.14

Zinc

MB22 0.012 0.11


Barium MB20 NA 0.17 0.1 (I) Retained as a chemical of interest on the basis of I criteria exceedence. MB17 NA 0.004 Cobalt MB22 NA 0.1

0.0014 (AEP) 0.05 (I) Retained as a chemical of interest on the basis of AEP and I criteria exceedences.

MB17 NA 0.73 MB20 NA 1.8 MB21 NA 0.15 Total manganese

MB22 NA 2.1

1.9 (AEP) 0.1 (RW)

0.2 (I)

Retained as a chemical of interest on the basis of AEP , I and 10-times RW criteria exceedences.

MB17 NA 0.037 MB20 NA 0.02 MB21 NA 0.02 Nickel

MB22 NA 0.072


Chlorobenzene MB8L 0.0905 0.052 0.055 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. 1.4-Dichlorobenzene MB21 0.2 <0.001 0.06 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. 1,2-Dichlorobenzene MB21 0.2 <0.001 0.16 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB21 0.032 <0.001 Cresols MB22 0.15 <0.001 0.001 (DL) Retained as a chemical of interest because detectable concentrations present.

Aroclor 1254 MB17 0.000005 0.000016 0.00001 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. MB21 NA 9.3 x 10-6 Acenaphthylene MB22 NA 9.3 x 10-6 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

Acenaphthene MB21 NA 7.9 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present. MB17 NA 6.0 x 10-5 MB21 NA 5.6 x 10-5 Fluorene MB22 NA 8.3 x 10-5

2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB21 NA 3.2 x 10-5 Anthracene MB22 NA 2.3 x 10-5

1.0 x 10-5 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB17 NA 2.7 x 10-5 MB20 NA 1.1 x 10-5 MB21 NA 2.6 x 10-4 Pyrene

MB22 NA 7.9 x 10-5


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(mg/L)



MB17 NA 6.3 x 10-6 MB20 NA 7.9 x 10-6 MB21 NA 1.4 x 10-4 Benzo(a)anthracene

MB22 NA 3.2 x 10-5


MB17 NA 7.6 x 10-6 MB20 NA 8.3 x 10-6 MB21 NA 1.7 x 10-4

Chrysene

MB22 NA 3.0 x 10-5



Benzo(b)fluoranthene

MB22 NA 2.8 x 10-5



Benzo(k)fluoranthene

MB22 NA 7.2 x 10-5


MB21 NA 5.6 x 10-5 Benzo(a)pyrene MB22 NA 2.8 x 10-5 1.0 x 10-5 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical

of interest. MB21 NA 3.7 x 10-5 Indeno(1,2,3cd)pyrene MB22 NA 1.4 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB21 NA 3.6 x 10-5 Benzo(g,h,i)perylene MB22 NA 1.5 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB17 NA 0.002 Bis(2-ethylhexyl)phthalate MB22 NA 0.002 0.001 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

1,2-Dichloroethane 10005 <0.001 0.031 0.01 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest..

Benzene 10005 0.06 0.055 0.01 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest..

Toluene MB22 1.2 0.002 0.18 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. Ethylbenzene MB22 0.16 <0.001 0.08 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB21 2.1 <0.001 Xylenes (m- and o-) MB22 2.8 <0.001 0.001 (DL) Retained as a chemical of interest because detectable concentrations present.

1,2,4-Trimethylbenzene MB22 0.49 0.29 0.001 (DL) Retained as a chemical of interest because detectable concentrations present.

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(mg/L)



10005 0.011 <0.01 MB5UR <0.01 0.011 MB8L 0.026 0.018 MB20 0.016 <0.01 MB21 0.025 <0.01

Acetone

MB22 0.017 <0.01

0.01 (DL) Retained as a chemical of interest because detectable concentrations present.

MB20 NA 0.05 MB21 NA 0.06 TPH C6-C9 MB22 NA 3.4


MB20 NA 0.06 MB21 NA 0.09 TPH C10-C14 MB22 NA 2.6


MB20 NA 0.08 TPH C15-C28 MB22 NA 0.2 0.05 (DL) Retained as a chemical of interest because detectable concentrations present.

Dibutyltin MB21 NA 0.00001 0.000005 (DL) Retained as a chemical of interest because detectable concentrations present. MB17 NA 56 MB20 NA 51 MB21 NA 48 Tripropyltin

MB22 NA 48

2 (DL) Retained as a chemical of interest because detectable concentrations present.

ABU = any beneficial use; AEP = aquatic ecosystem protection; RW = recreational water; I = irrigation water; DL = detection limit; NA = not analysed *Leeder/AGAL results

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Table 25. Summary of Exceedences – Southerly Flowing Older Volcanics Groundwater


Chemical Aquatic



Limit

TDS Nitrate (as N) Anionic surfactants Cyanide Ammonia (as N) Chromium total Copper Iron Mercury Zinc Barium Cobalt Total manganese Nickel Chlorobenzene 1,4-Dichlorobenzene 1,2-Dichlorobenzene Cresols Aroclor 1254 Acenaphthylene Acenaphthene Fluorene Anthracene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluroanthene Indeno(1,2,3cd)pyrene Benzo(g,h,i)perylene Bis(2-ethylhexyl)phthalate Toluene Ethylbenzene Xylenes (m- and o-) 1,2,4-Trimethylbenzene Acetone TPH C6-C9 TPH C10-C14 TPH C15-C28 Dibutyltin Tripropyltin

9.1.3 Werribee Formation Groundwater

The concentrations of chemicals found in each well in the southerly flowing Werribee Formation groundwater were compared with the beneficial use criteria for aquatic ecosystem protection, recreational1 waters, irrigation and stock-water. The only well screened in this

1 The recreational water criteria for toxicants are taken from the guidelines for raw waters for drinking purposes (ANZECC 1992), supplemented by the Australian Drinking Water Guidelines (NHMRC

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aquifer was MB5LR, and from the October and December 2003 sampling times, only three exceedences of criteria and/or detection limits were found. These were for TDS, total iron and mercury in October only.

Table 26 provides the detailed screening of the southerly flowing Werribee Formation groundwater, and shows the locations, by wells, of the beneficial use criteria exceedences. This table also provides a brief reasoning as to whether the chemical is carried through as a chemical of interest for further assessment.

Table 27 summarises the chemicals of interest as well as the beneficial use criteria (or in some cases the detection limit) that were exceeded in the southerly flowing Werribee Formation groundwater.

1996), where possible. As the guidelines are based on drinking water, comparison of the measured concentrations with ten-times the criteria was made (refer section 8.3).

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Table 26. Details of Chemical Screening for Southerly Flowing Werribee Formation Groundwater



(mg/L)



TDS MB5LR 4,400 4,300 3,500 (ABU) Retained as a chemical of interest on the basis of ABU criteria exceedence. Nitrate MB5LR 0.31 0.36 0.16 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Total iron MB5LR 0.45 0.29 0.3 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest.

Mercury MB5LR 0.004 <0.001 0.00006 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. ABU = any beneficial use; AEP = aquatic ecosystem protection; RW = recreational water; I = irrigation water; DL = detection limit; NA = not analysed

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Table 27. Summary of Exceedences – Southerly Flowing Werribee Formation Groundwater


Chemical Aquatic



Limit

TDS Nitrate Mercury

9.1.4 Silurian Groundwater

The concentrations of chemicals found in each well in the southerly flowing Silurain groundwater were compared with the beneficial use criteria for aquatic ecosystem protection, recreational1 waters, irrigation and stock-water.

Table 28 provides the detailed screening of the southerly flowing Silurian groundwater, and shows the locations, by wells, of the beneficial use criteria exceedences. This table also provides a brief reasoning as to whether the chemical is carried through as a chemical of interest for further assessment.

Table 29 summarises the chemicals of interest as well as the beneficial use criteria (or in some cases the detection limit) that were exceeded in the southerly flowing Silurian groundwater.


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Table 28. Details of Chemical Screening for Southerly Flowing Silurian Groundwater



(mg/L)



MB19 6,400 1,900 TDS MB18 6,900 2,100


Nitrate (as N) MB7L 0.4 0.32 0.16 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. MB7L 0.75 <0.01 MB19 0.6 0.6 Anionic surfactants MB18 0.5 2

0.14 (AEP) 0.2 (RW)


Ammonia (as N) MB18 0.85 0.3 0.01 (RW) Concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of RW criteria exceedence.

Chromium total MB19 <0.01 0.009 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. MB19 0.005 0.009 Copper MB18 0.003 <0.02 0.0014 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Iron MB18 2.5 1.8 0.3 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest.

Mercury MB19 0.0093 0.015/0.012* 0.00006 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. MB7L <0.01 0.02 Zinc MB19 0.009 0.077


Barium MB18 NA 0.17 0.1 (I) Retained as a chemical of interest on the basis of I criteria exceedence.

Cobalt MB18 NA 0.059 0.0014 (AEP) 0.05 (I) Retained as a chemical of interest on the basis of AEP and I criteria exceedences.

Total manganese MB18 NA 0.8 0.1 (RW) 0.2 (I)

Retained as a chemical of interest on the basis of I criteria exceedence only. Concentrations not greater than 10-times RW criteria.

Nickel MB18 NA 0.23 0.011 (AEP)

0.1 (RW) 0.2 (I)

Retained as a chemical of interest on the basis of AEP and I criteria exceedences only. Concentrations not greater than 10-times RW criteria.

MB19 NA 4.6 x 10-6 Acenaphthylene MB18 NA 4.8 x 10-6 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

Acenaphthene MB19 NA 9.3 x 10-6 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present. Fluorene MB19 NA 1.1 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB19 NA 1.9 x 10-5 Pyrene MB18 NA 3.4 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB19 NA 4.6 x 10-6 Benzo(a)anthracene MB18 NA 1.4 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB19 NA 4.6 x 10-6 Chrysene MB18 NA 1.7 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

MB19 NA 4.6 x 10-6 Benzo(b)fluoranthene MB18 NA 1.3 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

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Table 28. Details of Chemical Screening for Southerly Flowing Silurian Groundwater contd.



(mg/L)


(mg/L)

Criteria (mg/L) Comment

MB19 NA 4.6 x 10-6 Benzo(k)fluoranthene MB18 NA 1.0 x 10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

Indeno(1,2,3cd)pyrene MB18 NA 4.8 x 10-6 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present. Benzo(g,h,i)perylene MB19 NA 4.8 x 10-6 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present. Acetone MB7L <0.01 0.017 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. TPH C6-C9 MB18 NA 0.12 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. TPH C10-C14 MB18 NA 0.18 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. TPH C15-C28 MB18 NA 0.35 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. Methylethylketone MB18 0.015 <0.01 0.01 (DL) Retained as a chemical of interest because detectable concentrations present.

MB19 NA 51 Tripropyltin MB18 NA 52 2 (DL) Retained as a chemical of interest because detectable concentrations present.

EDTA MB18 NA 0.24 0.001 (DL) Retained as a chemical of interest because detectable concentrations present. ABU = any beneficial use; AEP = aquatic ecosystem protection; RW = recreational water; I = irrigation water; DL = detection limit; NA = not analysed

*Leeder/AGAL results

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Table 29. Summary of Exceedences – Southerly Flowing Silurian Groundwater


Chemical Aquatic



Limit

TDS Nitrate Anionic surfactants Ammonia (as N) Chromium total Copper Mercury Zinc Barium Cobalt Total manganese Nickel Acenaphthylene Acenaphthene Fluorene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluroanthene Indeno(1,2,3cd)pyrene Benzo(g,h,i)perylene Acetone TPH C6-C9 TPH C10-C14 TPH C15-C28 Methylethylketone Tripropyltin EDTA

9.2 Groundwater Flowing in a Northerly Direction

Groundwater wells 10006, MB6U, MB9L, MB13, MB23, MB14, MB6L, MB10, MB11, MB12 and MB24 were considered to be screened in groundwater with a northerly flow direction (refer section 6.0). These wells were then divided by aquifer into wells screened in the Older Volcanics (wells MB6U, MB9L, MB13, and MB23) and wells screened in the Silurian sandstone (wells MB6L, MB10, MB11, MB12 and MB24). Well MB14 is screened in silcrete, but has been grouped with the Silurian wells for the purposes of this report.

The following sections describe the chemicals that exceed the beneficial use criteria in each aquifer. Summary tables are provided in the text. Full tables of data are provided in Appendix D.

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9.2.1 Older Volcanics Groundwater

The concentrations of chemicals found in each well in the northerly flowing Older Volcanics groundwater were compared with the beneficial use criteria for aquatic ecosystem protection, recreational waters1, irrigation and stock-water.

Table 30 provides the detailed screening of the northerly flowing Older Volcanics groundwater, and shows the locations, by wells, of the beneficial use criteria exceedences. This table also provides a brief reasoning as to whether the chemical is carried through as a chemical of interest for further assessment.

Table 31 summarises the chemicals of interest as well as the beneficial use criteria (or in some cases the detection limit) that were exceeded in the northerly flowing Older Volcanics groundwater.


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Table 30. Details of Chemical Screening for Northerly Flowing Older Volcanics Groundwater



(mg/L)



10006 4,100 4,400 MB6U 19,000 20,000 MB9L 7,600 7,600 MB13 4,800 4,900

TDS

MB23 9,900 13,000


10006 0.17 <0.01 Nitrate (as N) MB23 NA 0.61 0.16 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB6U 0.04 0.32 MB9L 0.31 0.16 MB13 0.7 0.6

Anionic surfactants

MB23 0.3 0.5

0.14 (AEP) 0.2 (RW)


MB6U 0.014 0.013 Cyanide MB23 0.02 0.008 0.007 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

10006 0.2 0.2 MB6U 0.4 0.2 MB9L 0.1 <0.1 Ammonia (as N)

MB23 <0.3 0.02

0.01 (RW) Concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of RW criteria exceedence.

MB6U 0.021 0.013 MB9L 0.008 <0.01 MB13 0.004 0.004 Copper

MB23 0.002 0.005


10006 3.2 0.78 MB6U 12 2.3 MB9L 1 0.5 Iron

MB23 1.4 4.3

0.3 (RW) 1.0 (I)

Concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of RW and I criteria exceedences.

Mercury MB13 0.001 0.014 / 0.0015*

0.00006 (AEP) 0.001 (RW)

0.002 (I) 0.002 (SW)

Retained as a chemical of interest on the basis of AEP, I, SW and 10-times RW criteria exceedences.

MB6U 0.046 <0.01 MB9L 0.01 <0.01 MB13 0.076 <0.01 Zinc

MB23 0.037 0.058


Barium MB23 NA 0.5 0.1 (I) Retained as a chemical of interest on the basis of I criteria exceedence. MB13 NA 0.75

Boron MB23 NA 1.1

0.37 (AEP) 1.0 (RW)

0.5 (I)


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Table 30. Details of Chemical Screening for Northerly Flowing Older Volcanics Groundwater contd.



(mg/L)



MB13 NA 0.005 Cobalt MB23 NA 0.035 0.0014 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Total manganese MB23 NA 2.3 1.9 (AEP) 0.1(RW)

0.2 (I)

Retained as a chemical of interest on the basis of AEP, I, and 10-times RW criteria exceedences.

MB13 NA 0.063 Nickel MB23 NA 1.0

0.011 (AEP) 0.1 (RW)

0.2 (I)


Selenium MB23 NA 0.014 0.005 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. Silver MB13 <0.0005 0.01 0.00005 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. Chrysene MB13 NA 4.4 x10-6 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present. Benzo(b)fluoranthene MB23 NA 4.2 x10-6 2.5 x10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

1,1-dichloroethene MB13 0.005 0.004 0.0003 (RW) Concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of RW criteria exceedence.

10006 0.0084 <0.01 Dichloromethane MB13 0.0049 <0.01 0.004 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest..

1,2-dichloroethane MB13 0.024 0.019 0.01 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest..

Acetone MB6U 0.115 <0.01 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. C3 Alkyl benzenes MB23 NA 0.5 0.1 (DL) Retained as a chemical of interest because detectable concentrations present. TPH C6-C9 MB23 NA 0.11 0.01 (DL) Retained as a chemical of interest because detectable concentrations present.



MB13 NA 52 Tripropyltin MB23 NA 51 2 (DL) Retained as a chemical of interest because detectable concentrations present.

Formaldehyde MB23 NA 0.04 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. MB13 NA 2.5 EDTA MB23 NA 1.6 0.001 (DL) Retained as a chemical of interest because detectable concentrations present.

ABU = all beneficial uses for Segment B groundwater; AEP = aquatic ecosystem protection; RW = recreational water; I = irrigation water; SW = stock water; DL = detection limit; NA = not analysed *Leeder/AGAL results

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Table 31. Summary of Exceedences – Northerly Flowing Older Volcanics Groundwater


Chemical Aquatic



Limit

TDS Nitrate Anionic surfactants Cyanide Ammonia (as N) Copper Iron Mercury Zinc Barium Boron Cobalt Total manganese Nickel Selenium Silver Chrysene Benzo(b)fluoranthene 1,1-dichloroethene Acetone C3 Alkyl benzenes TPH C6-C9 TPH C10-C14 TPH C15-C28

Tripropyltin

Formaldehyde

EDTA

9.2.2 Silurian Groundwater

The concentrations of chemicals found in each well in the northerly flowing Silurian groundwater were compared with the beneficial use criteria for aquatic ecosystem protection, recreational waters1, irrigation and stock-water.

Table 32 provides the detailed screening of the northerly flowing Silurian groundwater, and shows the locations, by wells, of the beneficial use criteria exceedences. This table also provides a brief reasoning as to whether the chemical is carried through as a chemical of interest for further assessment. Table 33 summarises the chemicals of interest as well as the beneficial use criteria (or in some cases the detection limit) that were exceeded in the northerly flowing Silurian groundwater. 1 The recreational water criteria for toxicants are taken from the guidelines for raw waters for drinking purposes (ANZECC 1992), supplemented by the Australian Drinking Water Guidelines (NHMRC 1996), where possible. As the guidelines are based on drinking water, comparison of the measured concentrations with ten-times the criteria was made (refer section 8.3).

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Table 32. Details of Chemical Screening for Northerly Flowing Silurian Groundwater



(mg/L)



MB6L 15,000 15,000 MB10 7,200 7,100 MB11 3,700 3,600 MB12 7,900 9,700

TDS

MB24 4,200 3,100

3,500 (ABU) Retained as a chemical of interest on the basis of ABU criteria.

MB10 0.18 0.02 MB11 0.95 0.92 Nitrate (as N) MB12 NA 0.62


MB6L 0.21 <0.01 Anionic surfactants MB24 0.3 <0.01 0.14 (AEP) 0.2 (RW)


MB6L 0.3 0.2 MB10 <0.1 0.1 MB11 0.1 <0.1 Ammonia (as N)

MB24 <0.3 0.06

0.01 (RW) Concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of RW criteria exceedence.

Arsenic MB10 0.014 <0.001 0.013 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. MB14 0.003 <0.001 MB6L 0.014 0.011 MB10 0.016 0.011 MB12 0.011 0.007

Copper

MB24 0.001 0.001


MB6L 11 4.4 MB10 4.3 0.68 MB11 0.32 0.12 Iron

MB24 4.5 2.4

0.3 (RW) 1.0 (I)

Some concentrations above 10-times RW criteria. Retained as a chemical of interest on the basis of RW and I criteria exceedences.

MB14 <0.00005 0.0002 / 0.0004* Mercury MB12 0.0024 0.0035 / 0.0051* 0.00006 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB14 0.009 0.033 MB6L 0.02 <0.01 MB10 0.029 <0.01 MB11 0.021 <0.01 MB12 0.077 0.067

Zinc

MB24 0.043 0.093


Barium MB12 NA 0.12 0.1 (I) Retained as a chemical of interest on the basis of I criteria exceedence. MB14 NA 0.96 MB12 NA 0.95 Boron MB24 NA 0.5

0.37 (AEP) 0.5 (I) Retained as a chemical of interest on the basis of AEP and I criteria exceedences.

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Table 32. Details of Chemical Screening for Northerly Flowing Silurian Groundwater contd.



(mg/L)



Cobalt MB12 NA 0.003 0.0014 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. MB14 NA 0.18 Total manganese MB24 NA 0.12 0.1 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical

of interest.. Nickel MB24 NA 0.023 0.011 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence. Selenium MB12 NA 0.006 0.005 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

MB14 <0.0005 0.01 Silver MB12 <0.0005 0.01 0.00005 (AEP) Retained as a chemical of interest on the basis of AEP criteria exceedence.

Pyrene MB14 NA 1.1 x10-5 2.5 x 10-6 (DL) Retained as a chemical of interest because detectable concentrations present.

Dichloromethane MB10 0.0063 <0.01 0.004 (RW) Concentrations not greater than 10-times RW criteria. Not retained as a chemical of interest..

Methylethylketone MB24 0.013 <0.01 0.01 (DL) Retained as a chemical of interest because detectable concentrations present. MB14 0.021 <0.01 MB6L 0.016 <0.01 MB10 0.012 0.031 Acetone

MB12 0.016 <0.01





Monobutyltin MB24 NA 0.000006 0.000005 (DL) Retained as a chemical of interest because detectable concentrations present. MB12 NA 55 Tripropyltin MB24 NA 22 2 (DL) Retained as a chemical of interest because detectable concentrations present.

MB14 NA 0.13 MB12 NA 0.035 EDTA MB24 NA 0.008


AEP = aquatic ecosystem protection; RW = recreational water; I = irrigation water; DL = detection limit; NA = not analysed *Leeder/AGAL results

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Table 33. Summary of Exceedences – Northerly Flowing Silurian Groundwater


Chemical Aquatic



Limit

TDS Nitrate Anionic surfactants Ammonia (as N) Arsenic Copper Iron Mercury Zinc Barium Boron Cobalt Nickel Selenium Silver Pyrene Methylethylketone Acetone TPH C6-C9 TPH C10-C14 TPH C15-C28 Monobutyltin Tripropyltin EDTA

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10.0 CHEMICAL SCREENING OF MOONEE PONDS CREEK

10.1 Creek Water

Results of the extended Moonee Ponds Creek water monitoring programme for December 2003 and January 2004 were assessed below on the basis of upstream, opposite the site and downstream Creek locations. Measured concentrations in the water were compared with the freshwater aquatic ecosystem criteria shown in Table 20, or detection limits for chemicals with no criteria. The decision to retain a chemical as a “chemical of interest” for the supplementary risk assessment was based on the following decision process.

• If the concentration of the chemical was below criteria1 at all locations for both December 2003 and January 2004, it was not retained as a chemical of interest.

• If the concentration of the chemical was above criteria1 at some or all locations in either or both December 2003 and January 2004, but no pattern of increasing concentration at and/or downstream of the site could be seen, the chemical was not retained.

• If the concentration of the chemical was above criteria1 at some or all locations, and the highest concentrations are opposite and/or downstream of the site, the chemical was retained.

The details of the chemical screening are shown in Table 34. A summary of the chemicals retained as chemicals of interest is provided in Table 35.

It should be noted that urban waterways integrate inputs from groundwater and surface run-off. Moonee Ponds Creek in the vicinity of the Cleanaway site likely receives inputs such as run-off from roads, urban and industrial areas, andgroundwater via the Clean Fill landfill, the infilling associated with the former quarrying activities to the north, and the fuel depot. These surrounding land-uses may affect the list of chemicals retained for the supplementary risk assessment after further review.

The chemicals retained from the Creek water screening were compared with the results of the chemical screening of Creek sediment and groundwater from the site to identify links between groundwater (source) chemicals and Creek water and sediment (receiving environment) chemicals. The results of that linkage are discussed in section 11.2.

1 Or detection limits when no criteria are available

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Table 34. Details of Screening Process for Moonee Ponds Creek Water

Chemical Exceedence /

Detection Location

Location Number(s)

December 2003 Concentration

(mg/L)

January 2004 Concentration

(mg/L)

Criterion / Detection Limit

(mg/L) Comment

Upstream 2, 4 330, 510 170, 280 Opposite site 7, 8, 9 4,200, 1,200, 6,300 6,000, 700, 6,800 TDS Downstream 13, 15 850, 780 1,000, 1,100

3,500 (ABU) Exceedence at locations opposite site only for December 2003 and January 2004. Retained as a chemical of interest.

Upstream 2, 4 4, <0.1 0.3, 0.5 Opposite site 7, 8, 9 1, <0.1, 0.5 0.8, 0.4, 0.3 Anionic surfactants Downstream 13, 15 <0.1, <0.1 <0.1, <0.1

0.01 (DL) Similar upstream and opposite site concentrations for December 2003 and January 2004. Not retained as a chemical of interest.

Upstream 2, 4 0.53, 0.58 <0.005, <0.005 Opposite site 7, 8, 9 0.64, <0.3, <0.3 <0.005, <0.005, <0.005 Cyanide Downstream 13, 15 <0.3, <0.3 <0.005, <0.005

0.007 Similar upstream and opposite site concentrations for December 2003. All non-detectable concentrations in January 2004. Not retained as a chemical of interest.

Upstream 2, 4 <0.0001, <0.0001 <0.0001, <0.0001 Opposite site 7, 8, 9 0.001, 0.0005, <0.0001 <0.0001, <0.0001, <.0001 Cadmium Downstream 13, 15 <0.0001, <0.0001 <0.0001, <0.0001

0.0002 Exceedence only at locations opposite site only for December 2003. Retained as a chemical of interest.

Upstream 2, 4 0.003, 0.005 0.003, <0.001 Opposite site 7, 8, 9 0.011, 0.19, 0.012 <0.001, <0.001, 0.004 Copper Downstream 13, 15 0.002, 0.006 <0.001, <0.001

0.0014 Highest concentrations opposite site for both December 2003 and January 2004. Retained as a chemical of interest.

Upstream 2, 4 0.48, 0.77 0.47, 0.35 Opposite site 7, 8, 9 <0.05, 0.19, <0.05 <0.05, 0.17, <0.05 Iron Downstream 13, 15 0.16, 0.14 <0.05, <0.05

0.05 (DL) Highest concentrations upstream of site for both December 2003 and January 2004. Not retained as a chemical of interest.

Upstream 2, 4 0.001, 0.003 <0.001, <0.001 Opposite site 7, 8, 9 <0.001, 0.012, <0.001 <0.001, <0.001, <0.001 Lead Downstream 13, 15 <0.001, 0.001 <0.001, <0.001

0.0034 Exceedence only at Location 8 opposite site for December 2003 only. Retained as a chemical of interest.

Upstream 2, 4 0.0005, 0.0003 <0.0001, <0.0001 Opposite site 7, 8, 9 0.0002, <0.0001, <0.0001 <0.0001, <0.0001, <0.0001 Mercury Downstream 13, 15 <0.0001, <0.0001 <0.0001, <0.0001

0.00006 Exceedences at locations upstream and opposite site for December 2003 only. Highest concentrations at upstream locations. Not retained as a chemical of interest.

Upstream 2, 4 0.068, 0.046 0.068, 0.051 Opposite site 7, 8, 9 0.1, 0.2, 0.076 0.074, 0.063, 0.048 Zinc Downstream 13, 15 0.1, 0.069 0.033, 0.047

0.008 Highest concentrations opposite site for December 2003 and January 2004. Retained as a chemical of interest.

Upstream 2, 4 <0.05, <0.05 <0.05, <0.05 Opposite site 7, 8, 9 <0.05, 0.072, <0.05 <0.05, <0.05 Aluminium Downstream 13, 15 <0.05, <0.05 <0.05, <0.05

0.055 Exceedence at location 8 only opposite site for December 2003 only. Retained as a chemical of interest.

Upstream 2, 4 0.032, 0.025 0.019, 0.024 Opposite site 7, 8, 9 0.22, 0.04, 0.37 0.095, 0.043, 0.422 Barium Downstream 13, 15 0.085, 0.038 0.086, 0.057

0.01 (DL) Highest concentrations opposite site for both December 2003 and January 2004. Retained as a chemical of interest.

Upstream 2, 4 <0.1, <0.1 3.5, 4.1 Opposite site 7, 8, 9 0.2, 1.4, 1.4 3.3, 0.1, 12 Boron Downstream 13, 15 1.2, 1.1 12, 12

0.37 Highest concentrations opposite site and in downstream water for December 2003 and January 2004. Retained as a chemical of interest.

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Table 34. Details of Screening Process for Moonee Ponds Creek Water contd.


Detection Location

Location Number(s)


(mg/L)


(mg/L)


(mg/L) Comment

Upstream 2, 4 0.002, <0.001 <0.001, <0.001 Opposite site 7, 8, 9 0.005, 0.004, 0.009 0.002, <0.001, 0.012 Cobalt Downstream 13 0.008, <0.001 0.003, <0.001

0.0014 Highest concentrations opposite site and in downstream water for December 2003 and January 2004. Retained as a chemical of interest.

Upstream 2, 4 0.3, 0.3 0.11, 0.16 Opposite site 7, 8, 9 <0.1, <0.1, <0.1 <0.1, <0.1, <0.1 Ferrous Iron Downstream 13, 15 <0.1, <0.1 <0.1, 0.13

0.1 (DL) Highest concentrations upstream for December 2003 and January 2004. Not retained as a chemical of interest.

Upstream 2, 4 0.2, 0.2 0.078, 0.301 Opposite site 7, 8, 9 5.1, 0.78, 5.4 1.64, 0.395, 6.4 Total manganese Downstream 13, 15 2.4, 0.087 0.576, 0.236

1.9 Highest concentrations opposite site. Retained as a chemical of interest.

Upstream 2, 4 <0.1, <0.1 <0.01, <0.01 Opposite site 7, 8, 9 0.17, 0.055, 0.19 0.08, 0.02, 0.213 Nickel Downstream 13, 15 0.018, 0.018 0.025, 0.025

0.011 Highest concentrations opposite site and in downstream water. Retained as a chemical of interest.

Upstream 2, 4 0.012, <0.012 <0.001, <0.001 Opposite site 7, 8, 9 <0.012, <0.01, <0.01 <0.001, <0.001, <0.001 Silver Downstream 13, 15 <0.01, <0.01 <0.001, <0.001

0.00005 Highest concentrations upstream of site. Not retained as a chemical of interest.

Upstream 2, 4 0.000038, 0.00008 <0.000001, <0.000001

Opposite site 7, 8, 9 0.000049, <0.000001, <0.000001

<0.000001, <0.000001, <0.000001 Aroclor 1254

Downstream 13, 15 <0.000001, <0.000001 <0.000001, <0.000001

0.00001 Concentrations detected upstream of site and only at one opposite site location. Not retained as a chemical of interest.

Upstream 2, 4 7.5 x 10-6, <2.5 x 10-6 <1.0 x 10-7, <1.0 x 10-7

Opposite site 7, 8, 9 <2.5 x 10-6, 7.0 x 10-5, 9.5 x 10-5

<1.0 x 10-7, <1.0 x 10-7, <1.0 x 10-7 Acenapthylene

Downstream 13, 15 <2.5 x 10-6, 3.0 x 10-5 <1.0 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)

Highest concentrations opposite site and in downstream water. Retained as a chemical of interest.

Upstream 2, 4 2.2 x 10-5, 6.7 x 10-5 <1.0 x 10-7, <1.0 x 10-7

Opposite site 7, 8, 9 9.0 x 10-5, 2.5 x 10-5, 2.5 x 10-6

<1.0 x 10-7, 2.7 x 10-6, <1.0 x 10-7 Acenaphthene

Downstream 13, 15 2.5 x 10-5, 7.5 x 10-5 <1.0 x 10-7, <1.0 x 10-71

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 1.0 x 10-5, 6.5 x 10-5 2.1 x 10-6, <1.0 x 10-7


<1.0 x 10-7, 2.4 x 10-5, 3.0 x 10-7 Phenanthrene

Downstream 13, 15 5.0 x 10-5, 1.5 x 10-4 1.6 x 10-7, 4.5 x 10-5

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 <2.5 x 10-6, 1.1 x 10-5 4.1 x 10-7, 3.4 x 10-7

Opposite site 7, 8, 9 4.6 x 10-6, 7.0 x 10-5,4.0 x 10-5

<1.0 x 10-7, 6.2 x 10-6, 6.5 x 10-7 Fluorene

Downstream 13, 15 1.0 x 10-5, 1.0 x 10-4 <1.0 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


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Detection Location

Location Number(s)


(mg/L)


(mg/L)


(mg/L) Comment

Upstream 2, 4 1.3 x 10-5, 5.1 x 10-5 3.4 x 10-6, 3.8 x 10-6


1.0 x 10-7, 4.0 x 10-5, 5.5 x 10-6 Pyrene

Downstream 13, 15 6.5 x 10-5, 5.0 x 10-5 2.7 x 10-6, 1.9 x 10-5

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 5.0 x 10-6, 2.4 x 10-5 1.6 x 10-6, 3.1 x 10-6


<1.0 x 10-7, 2.0 x 10-5, 3.3 x 10-6

Benzo(a) anthracene

Downstream 13, 15 5.5 x 10-5, 4.0 x 10-5 5.8 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 4.5 x 10-6, 2.2 x 10-5 1.3 x 10-6, 2.9 x 10-6


<1.0 x 10-7, 1.4 x 10-5, 2.3 x 10-6 Chrysene

Downstream 13, 15 5.5 x 10-5, 2.5 x 10-5 5.3 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 4.8 x 10-6, 2.2 x 10-5 1.0 x 10-6, 2.3 x 10-6


<1.0 x 10-7, 1.0 x 10-5, 2.5 x 10-6

Benzo(b) fluoranthene

Downstream 13, 15 5.5 x 10-5, 4.0 x 10-5 3.1 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 6.0 x 10-6, 1.5 x 10-5 1.0 x 10-6, 2.7 x 10-6


<1.0 x 10-7, 1.3 x 10-5, 2.4 x 10-5

Benzo(k) fluoranthene

Downstream 13, 15 4.0 x 10-5, 3.5 x 10-5 3.7 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 3.6 x 10-6,9.0 x 10-6 4.6 x 10-7, 1.6 x 10-6


<1.0 x 10-7, 6.4 x 10-6, 1.3 x 10-6

Indeno(1,2,3cd) pyrene

Downstream 13, 15 2.5 x 10-5, 2.0 x 10-5 <1.0 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 9.5 x 10-6, 1.2 x 10-5 8.8 x 10-7, 2.3 x 10-6


<1.0 x 10-7, 6.4 x 10-6, 1.3 x 10-6

Benzo(g,h,i) perylene

Downstream 13, 15 2.5 x 10-5, 2.0 x 10-5 <1.0 x 10-7, <1.0 x 10-7

2.5 x 10-6 and 1.0 x 10-7 (DL)


Upstream 2, 4 <0.001, <0.001 <0.001, <0.001

Opposite site 7, 8, 9 <0.001, <0.01, <0.001 <0.001, 0.0018 (0.0016), <0.001

1,2-dichloroethene

Downstream 13, 15 <0.001, <0.001 <0.001, <0.001

0.01 – 0.001 (DL)

Highest concentrations opposite site in January 2004 only. Retained as a chemical of interest.

Upstream 2, 4 <0.01, <0.01 <0.01, <0.01 Opposite site 7, 8, 9 <0.01, 0.025, <0.01 <0.01, <0.01, <0.01 Carbon disulfide Downstream 13, 15 <0.01, <0.01 <0.01, <0.01

0.02 Detectable concentrations opposite the site in December 2003 only. Retained as a chemical of interest.

Upstream 2, 4 0.29, 0.51 <0.05, <0.05 Opposite site 7, 8, 9 0.53, 0.14, 0.72 0.13, <0.05, <0.05 TPHs (C6-C36) Downstream 13, 15 <0.05, <0.05 0.079, <0.05

0.05 (DL) Highest concentrations opposite the site in December 2003 and January 2004. Retained as a chemical of interest.

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Detection Location

Location Number(s)


(mg/L)


(mg/L)


(mg/L) Comment

Upstream 2, 4 42, 43 NA Opposite site 7, 8, 9 52, 62, 38 NA Tripropyltin Downstream 13, 15 55, 41 NA

2 (DL) Similar concentrations detected upstream of site and opposite site. Not retained as a chemical of interest.

Upstream 2, 4 <0.001, <0.001 <0.001, <0.001 Opposite site 7, 8, 9 0.001 – 0.005 <0.001, <0.001, <0.001 Aliphatic alkanes* Downstream 13, 15 <0.001, <0.001 <0.001, <0.001

0.001 (DL) Detected at Location 8 only opposite the site in December 2003 only. Retained as a chemical of interest.

Upstream 2, 4 0.02, 0.01 0.08, 0.08 Opposite site 7, 8, 9 0.01, <0.01, <0.01 0.1, 0.11, 0.48 Formaldehyde Downstream 13, 15 0.01, <0.01 0.11, 0.15

0.01 (DL) Highest concentrations detected opposite site in January 2004. Retained as a chemical of interest.

Upstream 2, 4 0.13, 0.08 0.024, 0.009 Opposite site 7, 8, 9 6.2, 0.008, 0.6 14, 0.053, 2.4 EDTA Downstream 13 0.006 0.27, 0.59

0.001 (DL) Highest concentrations opposite site. Retained as a chemical of interest.

All chemical concentrations compared with criteria provided in Table 3.4.1 in ANZECC and ARMCANZ (2000)., or detection limit if no criteria available. ABU = any beneficial use; DL = detection limit; NA = not analysed Numbers in brackets are the secondary laboratory results. *The aliphatic alkanes tetradecane, petadecane, hexadecane, octadecane, nonadecane, eicosane, heneicosane, docosane, tricosaneand tetracosane were detected at location 8 only and were retained as chemicals of interest.

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Table 35. Results of Moonee Ponds Creek Water Chemical Screening

Chemicals with Concentrations Below

Criteria1 (Not retained)A

Chemicals with No Pattern of Concentration with Location

(Not retained)B

Chemicals Above Criteria and with a Pattern of Concentration

(Retained)C Ammonia Cyanide TDS Arsenic Aroclor 1254 Cadmium Total chromium Anionic surfactants Copper Chromium VI Iron Lead Chromium III Mercury Zinc Molybdenum Ferrous Iron Aluminium Tin Silver Barium Chlorinated hydrocarbons Phthalates Boron Phenols Tripropyltin Cobalt Polychlorinated biphenyls (except Aroclor 1254)

Manganese

Naphthalene Nickel Phenanthrene Acenaphthylene Fluoranthene Acenaphthene Benzo(a)pyrene Phenanthrene Phthalates2 Fluorene Volatile organic compounds3 Pyrene Additional semi-volatiles Benzo(a)anthracene Organotin compounds4 Chrysene Toxic substances Benzo(b)fluoranthene Additional analytes5 Benzo(k)fluoranthene Indeno(1,2,3cd)pyrene Benzo(g,h,I)perylene 1,2-dichloroethene Carbon disulfide TPHs (C6-C36) Aliphatic alkanes Formaldehyde EDTA A The concentration of the chemical was below criteria and/or detection limits at all locations and times

B The concentration of the chemical was above criteria and/or detection limits at some or all locations and some or all times, but no pattern of increasing concentration at and/or downstream of the site could be seen

C The concentration of the chemical was above criteria and/or detection limits at some or all locations, and the highest concentrations are opposite and/or downstream of the site

1 and/or detection limits 2 No phthalates were found to be above detection limits. Only some phalates have criteria. 3 With the exception of 1,2-dichloroethene and carbon disulfide 4 With the exception of tripropyltin 5 With the exception of formaldehyde and EDTA

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10.2 Creek Sediment

The same process as that used for the Moonee Ponds Creek water was followed for the sediment. That is, the results of the Moonee Ponds Creek sediment monitoring for December 2003 and January 2004 are discussed below on the basis of upstream, at the site and downstream Creek locations. Measured data were compared with the low interim sediment quality guidelines (ISGQ-low) shown in Table 20, or detection limits for chemicals with no criteria. The decision to retain a chemical as a “chemical of interest” for the supplementary risk assessment was based on the following decision process.

• If the concentration of the chemical was below criteria1 at all locations for both December 2003 and January 2004, it was not retained for the supplementary risk assessment.

• If the concentration of the chemical was above criteria1 at some or all locations in either or both December 2003 and January 2004, but no pattern of increasing concentration at and/or downstream of the site could be seen, the chemical was not retained for the supplementary assessment.

• If the concentration of the chemical was above criteria1 at some or all locations, and the highest concentrations are opposite and/or downstream of the site, the chemical was retained for the supplementary assessment.

The details of the chemical screening are shown in Table 36. A summary of the chemicals retained as chemicals of interest is provided in Table 37.

It should be noted that factors, such as run-off from other areas, groundwater inputs to the Creek from the north, nearby land-uses and analytical and sampling errors may reduce the list of chemicals retained for the supplementary risk assessment after further review.

The chemicals retained from the Creek sediment screening were compared with the results of the chemical screening of Creek water and groundwater from the site to find links between groundwater (source) chemicals and Creek water and sediment (receiving environment) chemicals. The results of that linkage are discussed in section 11.2.

1 Or detection limits when no criteria are available

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Table 36. Details of Screening Process for Moonee Ponds Creek Sediment


Detection Location

Location Number(s)


(mg/kg)


(mg/kg)


(mg/kg) Comment

Upstream 2, 4 NA, 18 21, 10 Opposite site 7, 8, 9 NA, 150, 20 11, 3, <5 Ammonia (as N) Downstream 13, 15 <5, <6 <5, <5

5 – 6 (DL) Highest concentrations detected opposite site. Retained as a chemical of interest.

Upstream 2, 4 NA, 20 80, 12 Opposite site 7, 8, 9 36, 65, 51 10, 19, 15 Chromium (total) Downstream 13, 15 31, 41 16, 10

5 (DL) No pattern of concentration with location. Not retained as a chemical of interest.

Upstream 2, 4 NA, 11,000 56,800, 16,800 Opposite site 7, 8, 9 44,000, 11,000, 40,000 15,200, 13,200, 14,000, Iron (total) Downstream 13, 15 36,000, 24,000 22,000, 9,800


Upstream 2, 4 NA, <0.1 0.8, 0.3 Opposite site 7, 8, 9 <0.5, <0.1, <0.1 <0.05, 0.2, <0.1 Mercury Downstream 13, 15 <0.1, <0.3 <0.1, <0.1

0.05 - 0.1 (DL) No pattern of concentration with location. Not retained as a chemical of interest.

Upstream 2, 4 NA, 2,500 5,100, 2,000 Opposite site 7, 8, 9 1,200, 30,000, 7,100 5,700, 3,100, 2,900 Aluminium Downstream 13, 15 2,400, 9,700 4,600, 2,600

5 (DL) Highest concentrations detected opposite site. Retained as a chemical of interest.

Upstream 2, 4 NA, 150 320, 36 Opposite site 7, 8, 9 300, 240, 90 95, 61, 31 Barium Downstream 13, 15 32, 140 68, 34


Upstream 2, 4 NA, 20 80, 12 Opposite site 7, 8, 9 36, 65, 51 10, 19, 15 Chromium (Cr III) Downstream 13, 15 31, 41 16, 10


Upstream 2, 4 NA, 32 25, 8 Opposite site 7, 8, 9 36, 19, 25 11, 6, 8 Cobalt Downstream 13, 15 17, 26 12, 6


Upstream 2, 4 NA, 800 160, 74 Opposite site 7, 8, 9 3,400, 490, 400 220, 380, 81 Total manganese Downstream 13, 15 170, 1,100 230, 99

5 (DL) Highest concentrations detected opposite site. Retained as a chemical of interest.

Upstream 2, 4 NA, 55 46, 12, Opposite site 7, 8, 9 66, 85, 45 18, 14, 15 Nickel Downstream 13, 15 32, 43 19, 11

21 (ISQGlow) 52 (ISQGhigh)

Highest concentrations detected opposite site. Retained as a chemical of interest.

Upstream 2, 4 NA, <5 <5, <5 Opposite site 7, 8, 9 <5, <5, <5 <5, <5, <5 Tin Downstream 13, 15 <5, 6 <5, <5


Upstream 2, 4 NA, <5 <5, <5 Opposite site 7, 8, 9 <5, <5, <5 <5, <5, <5 Eucalyptol Downstream 13, 15 <5, <5 <5, 120


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Table 36. Details of Screening Process for Moonee Ponds Creek Sediment contd.


Detection Location

Location Number(s)


(mg/kg)


(mg/kg)


(mg/kg) Comment

Upstream 2, 4 NA, <10 <10, <10 Opposite site 7, 8, 9 <10, <10, <10 <10, <10, <10 TPH C6-C10 Downstream 13, 15 <10, <10 <10, 17

10 (DL) Highest concentrations downstream of site. Retained as a chemical of interest.

Upstream 2, 4 NA, <10 <10, <10 Opposite site 7, 8, 9 11, <10, <10 <10, <10, <10 TPH C10-C14 Downstream 13, 15 <10, <10 <10, 310

10 (DL) Highest concentrations opposite and/or downstream of site. Retained as a chemical of interest.

Upstream 2, 4 NA, <20 <20, <20 Opposite site 7, 8, 9 38, <20, <20 <20, <20, <20 TPH C15-C28 Downstream 13, 15 <20, 47 <20, 440


Upstream 2, 4 NA, <20 <20, <20 Opposite site 7, 8, 9 26, <20, <20 <20, <20, <20 TPH C29-C36 Downstream 13, 15 <20, 48 <20, 440


Upstream 2, 4 NA, 28 NA, NA Opposite site 7, 8, 9 NA, 31, 48 NA, NA, NA Tripropyltin Downstream 13, 15 54, 47 NA, NA

0.0002 (DL) Highest concentrations downstream of site. Retained as a chemical of interest.

Upstream 2, 4 NA, NA 5.4, 11.2 Opposite site 7, 8, 9 NA, NA, NA 14.3, 16.3, 6.2 Formaldehyde Downstream 13, 15 NA, NA 12, 16

0.5 (DL) Highest concentrations detected opposite site. Retained as a chemical of interest.

Upstream 2, 4 NA, NA 0.5, <0.5 Opposite site 7, 8, 9 NA, NA, NA 0.62, <0.5, <0.5 EDTA Downstream 13, 15 NA, NA <0.5, 0.51

0.5 (DL) No pattern of concentration with location. Not retained as a chemical of interest.

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Table 37. Results of Moonee Ponds Creek Sediment Chemical Screening

Chemicals with Concentrations Below

Criteria1 (Not retained)A

Chemicals with No Pattern of Concentration with Location

(Not retained)B

Chemicals Above Criteria and with a Pattern of Concentration

(Retained)C Cyanide Iron Ammonia Arsenic Chromium (total) Aluminium Cadmium Chromium III Total manganese Chromium VI Mercury Nickel Copper Barium Formaldehyde Lead Cobalt TPHs C6-C10 Zinc Tin TPHs C11-C14 Boron Additional semi-volatiles TPHs C15-C28 Ferrous Iron Eucalyptol TPHs C29-C36 Molybdenum EDTA Tripropyltin Selenium Silver Chlorinated hydrocarbons Phenols Polychlorinated biphenyls Polynuclear aromatic hydrocarbons

Phthalates Volatile organic compounds Additional semi-volatiles2 Organotin compounds3 Toxic substances Additional analytes4

A. The concentration of the chemical was below criteria and/or detection limits at all locations and times

B. The concentration of the chemical was above criteria and/or detection limits at some or all locations and some or all times, but no pattern of increasing concentration at and/or downstream of the site could be seen

C. The concentration of the chemical was above criteria and/or detection limits at some or all locations, and the highest concentrations are opposite and/or downstream of the site

1 and/or detection limits 2 With the exception of eucalyptol 3 With the exception of tripropyltin 4 With the exception of formaldehyde

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11.0 PRELIMINARY RISK ASSESSMENT (AQUEOUS PHASE)

The prioritisation of chemicals identified as chemicals of interest in the groundwater is discussed in the following sections. The assessment has divided the groundwater into two areas: groundwater to the south and groundwater to the north. This approach was undertaken due to the proximity of the Moonee Ponds Creek to the north of the site as an immediate receiving environment (and “beneficial use”) of groundwater that may affect the priority for further assessment and/or monitoring in this area of the site.

The chemicals of interest that were identified from the screening processes in sections 9.0, and 10.0 have been qualitatively assigned a rank of low, medium or high priority chemicals. The rank for each chemical was developed after consideration of chemical concentrations, consistency of data over time and location, location(s) of the chemical exceedences, and other factors such as natural background concentrations of some inorganic compounds.

The ranking system for the chemicals of interest used the following process:

• Low priority chemicals are those that:

• are found in wells not near to any existing beneficial uses of groundwater; and that

• are found in on-site wells only, or do not appear to have migrated far from the site, or those that

• do not appear in many wells; or

• those that may be associated with natural background groundwater conditions.

• Medium priority chemicals are those that are found in wells not near to any existing beneficial uses of groundwater and that:

• appear to have migrated in groundwater to wells off the site; and

• are significantly higher than criteria; and/or

• exceed criteria in wells across times and locations.

• High priority chemicals are those found in wells near to an existing beneficial use of groundwater (e.g., near to the Moonee Ponds Creek).

The intent of the following sections is not to quantify the potential risks that the chemicals of interest present to the environment (which includes ecosystems and human health), but to identify priorities for chemicals that should be assessed further, either through additional monitoring, fate and transport modelling, and/or a quantitative risk assessment. Recommendations for continued monitoring and/or assessment have been made, where appropriate.

The potential for, and types of, effects of the chemicals of interest can be assessed in a supplementary risk assessment. It is noted that the scientific literature on synergistic effects of groups or mixtures of chemicals is limited and that criteria are set conservatively low to allow for uncertainties such as synergism.

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11.1 Southern Groundwater Table 38 combines the results of Table 23, Table 25, Table 27 and Table 29 to show patterns of chemicals within different aquifers to the south of the site. Also shown in Table 38 is whether the chemicals of interest have been detected in leachate wells on the site.

Table 38 shows that the majority of the chemicals of interest identified from the screening process are in the groundwater in the Older Volcanics aquifer, and very few chemicals of interest are in the groundwater in the Werribee Formation aquifer. It should be noted that only one well (MB5LR) was screened in the Werribee formation aquifer, and the full analytical suite of Schedule A and Schedule B parameters was not analysed in the groundwater samples from this well. Hence, further assessment of groundwater from well MB5LR may alter the list of chemicals of interest in the groundwater in this aquifer.

Table 38. Summary of Exceedences – Southerly Flowing Groundwater

Exceedence by Aquifer

Chemical Aqueous Leachate1

Brighton Group

Older Volcanics

Werribee Formation Silurian

TDS Nitrate Anionic surfactants Cyanide Ammonia (as N) Chromium total Copper Iron Mercury Zinc Barium Cobalt Total manganese Nickel Selenium Chlorobenzene 1,4-Dichlorobenzene 1,2-Dichlorobenzene Cresols Aroclor 1254 2 Acenaphthylene Acenaphthene Fluorene Anthracene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluroanthene Indeno(1,2,3cd)pyrene Benzo(g,h,i)perylene Bis(2-ethylhexyl)phthalate

1 Detected in one or more leachate wells on any monitoring occasion. 2 Higher aqueous concentrations measured in the leachate are most likely an artefact of contamination from overlying LNAPL during sampling.

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Table 38. Summary of Exceedences – Southerly Flowing Groundwater contd.

Exceedence by Aquifer

Chemical Aqueous Leachate1

Brighton Group

Older Volcanics

Werribee Formation Silurian

Toluene Ethylbenzene Xylenes (m- and o-) 1,2,4-Trimethylbenzene Acetone TPH C6-C9 TPH C10-C14 TPH C15-C28 Methylethylketone Dibutyltin Tripropyltin EDTA

The qualitative assessment of risks of the chemicals of interest in the southerly flowing groundwater is shown in Table 39. The chemicals of interest that were ranked medium priority chemicals are TDS, anionic surfactants, mercury, zinc, PAHs, PCBs (Aroclor 1254), acetone and TPHs. The remaining chemicals of interest were ranked as low priority chemicals.

No chemicals of interest in the southerly flowing groundwater were ranked as high priority chemicals, as groundwater to the south of the site is not flowing to a nearby surface waterbody nor extracted for irrigation, stock-water or domestic use (e.g., filling a swimming pool)2.

Overall, the chemicals detected in the aqueous phase of leachate migrating off the site to the south are considered to be of low to medium priority for further assessment.

1 Detected in one or more leachate wells on any monitoring occasion. 2 The groundwater database search found 38 wells within two kilometers of the site, of which all but seven were listed as investigation or observation wells. The use of the remaining wells was listed as either not known or miscellaneous. Refer Appendix G.

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Table 39. Prioritisation of Chemicals of Interest in the Southern Groundwater

Chemical Wells Aquifers On-site / Off-site

Highest concentration

(mg/L) Criteria Comment Priority

TDS

MB15, Tulla3U, MB4UR, MB16, 10005, MB4LB, MB5UR, MB8L, MB17, MB20, MB22, MB5LR, MB19, MB18

BG, OV, W, S

On-site and off-site 15,000 3,500 (ABU)

Highest concentrations in wells screened across the water-table in the OV and BG aquifers. Shallow groundwater in the OV and BG aquifers most affected.

Med

Nitrate Tulla3U, MB4UR, MB5UR, MB7L, MB8L

BG, OV, W, S On-site 1.5 0.16 (AEP) On-site wells only Low

Anionic surfactants MB8L, MB18, MB19 BG, OV, S

On-site and off-site 1.7 0.14 (AEP) Localised to wells in central south Med

Cyanide MB5UR, MB8L OV On-site 0.02 0.007 (AEP) On-site wells only Low

Ammonia (as N) Tulla3L, MB4LB, MB8L, MB18 OV, S On-site and

off-site 0.85 0.01 (RW) One off-site exceedence at MB18. Med

Chromium total MB8L, MB20, MB19 OV, S On-site and off-site 0.017 0.01 (DL)

Detectable concentrations only in two off-site wells. Chromium VI concentrations meet AEP criterion

Low

Copper MB15, MB4UR, MB16, MB17, MB20, MB21, MB22, MB19, MB18

BG, OV, S

On-site and off-site 0.02 0.0014

(AEP)

Off-site concentrations exceed AEP criterion to southeast and south, but no nearby surface waterbodies to the south

Med

Iron 10005, Tulla3L, MB4LR, MB5UR, MB8L,MB17, MB20, MB21, MB22

OV On-site and off-site 9.1 0.3 (RW) Exceeds 10-times RW criteria in MB4LR, MB8L,

and MB20 only. Minor off-site exceedence. Med

Mercury MB20, MB21, MB5LR, MB19 OV, W, S On-site and

off-site 0.015 0.00006 (AEP)

Three-orders of magnitude over AEP criteria, but no nearby surface water bodies to the south Med

Zinc MB4UR, MB16, MB7L, MB8L, MB17, MB20, MB21, MB22

BG, OV, S

On-site and off-site 0.14 0.008 (AEP) Two order of magnitude over AEP criteria, but no

nearby surface waterbodies to the south Med

Barium MB16, MB20, MB18 BG, OV, S Off-site* 0.8 0.1 (I)

Minor exceedences in MB20 and MB17. Off-site wells only may indicate natural background concentrations

Low

Cobalt MB15, MB16, MB17, MB22, MB18

BG, OV, S Off-site* 0.1

0.0014 (AEP) 0.05 (I)

Concentrations in leachate similar to groundwater. May indicate natural background concentrations Low

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Table 39. Prioritisation of Chemicals of Interest in the Southern Groundwater contd.




Total manganese MB15, MB17, MB20, MB21, MB22, MB18

BG, OV, S Off-site* 2.1 0.1 (RW)

0.2 (I) Manganese can be associated with natural background concentrations Low

Nickel MB15, MB16, MB17, MB20, MB21, MB22, MB18

BG, OV, S Off-site* 0.23 0.011 (AEP)

0.2 (I)

An order of magnitude above AEP criterion, but no surface waterbodies to the south. Only marginally above I criterion.

Low

Selenium MB15, MB16 BG Off-site* 0.02 0.005 (AEP) No nearby surface waterbodies to the south. May be associated with natural background concentrations.

Low

Chlorobenzene MB8L OV On-site 0.09 0.055 (AEP) On-site well only. No nearby surface waterbodies Low 1,4-Dichlorobenzene MB21 OV Off-site 0.2 0.06 (AEP) One off-site well. No nearby surface waterbodies Low 1,2-Dichlorobenzene MB21 OV Off-site 0.2 0.16 (AEP) Minor exceedence in one offsite well. Low Cresols MB21, MB22 OV Off-site* 0.15 0.001 (DL) No criteria available. Two off-site wells only Low

Aroclor 1254 MB15, MB17 BG, OV Off-site 0.000018 0.00001 (AEP)

Minor exceedence of AEP criteria in two off-site wells Med

PAHs** MB15, MB16, MB21, MB22, MB19, MB18

BG, OV, S Off-site* 2.6E-4

(pyrene) 2.5E-6 (DL)

Chemicals of interest because no criteria available. With the exception of anthracene in the OV, PAHs with criteria were below their respective criteria

Med

Bis(2-ethylhexyl)phthalate

MB15, MB16, MB17, MB22 BG, OV Off-site* 0.005 0.001 (AEP) Minor exceedence of AEP criterion. No nearby

surface waterbodies to the south. Low

Toluene MB22 OV Off-site 1.2 0.18 (AEP) Order of magnitude exceedence of AEP criterion in one well. No nearby surface waterbodies to the south

Low

Ethylbenzene MB22 OV Off-site 0.16 0.08 (AEP) Order of magnitude exceedence of AEP criterion in one well. No nearby surface waterbodies to the south

Low

Xylenes (m- and o-) MB21, MB22 OV Off-site 2.8 0.001 (DL) Chemical of interest because no criterion and detectable concentrations present in two off-site wells

Med

1,2,4-Trimethylbenzene MB22 OV Off-site 0.49 0.001 (DL) Chemical of interest because no criterion and

detectable concentrations present in one well only Med

Acetone MB16, 10005, MB5UR, MB7L, MB8L, MB20, MB21, MB22

BG, OV, S

On-site and off-site 0.026 0.01 (DL)

Chemical of interest because no criterion and detectable concentrations present in eight wells, four of which are off-site

Med

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Table 39. Prioritisation of Chemicals of Interest in the Southern Groundwater contd.




TPHS C6-C28 MB20, MB21, MB22, MB18 BG, S Off-site* 0.6 0.05 (DL)

Chemical of interest because no criterion and detectable concentrations present in four off-site wells

Med

Methylethylketone MB18 S Off-site 0.015 0.01 (DL) Chemical of interest because no criterion and detectable concentrations present in one off-site well only

Low

Dibutyltin MB21 OV Off-site* 0.00001 0.000005 (DL)

Chemical of interest because no criterion and detectable concentrations present in one off-site well only

Low

Tripropyltin MB15, MB16, MB19, MB18

BG, OV, S Off-site* 64 2 DL Chemical of interest because no criterion and

detectable concentrations present in most wells. Med

EDTA MB18 S Off-site 0.24 0.001 (DL) Chemical of interest because no criterion and detectable concentrations present in one off-site well only

Low

ABU = any beneficial use; AEP = aquatic ecosystem protection, I = irrigation, RW = recreational water; DL = detection limit; OV = Older Volcanics; S = Silurian; W = Werribee Formation; BG = Brighton Group Neg = negligible, Med = medium * Not analysed in on-site wells **Acenaphthylene, acenaphthene, fluorene, anthracene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, indeno(1,2,3cd)pyrene, and benzo(g,h,i)perylene. With the exception of anthracene, these were detected in the BG, OV and S aquifers. Anthracene was detected in the OV only.

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11.2 Northern Groundwater The prioritisation of the chemicals of interest in the northern groundwater follows the process outlined in section 11.0, which was used to rank the identified chemicals of interest in the southerly flowing groundwater.

The hydrogeological conceptual model indicates the Moonee Ponds Creek is controlling the northerly groundwater movement. Due to the close proximity of the Creek and the fact that the hydrogeological model indicates that the northerly flowing groundwater is discharging into the Creek, the prioritisation of the chemicals of interest in the northern groundwater was considered to be significantly different to that undertaken for the southern groundwater. While other beneficial uses of groundwater (such as stock-water and irrigation) to the north of the site are not known, the presence of the Creek (as an existing beneficial use) places a higher priority on the supplementary assessment of the chemicals of interest in the northerly flowing groundwater.

In order to appropriately rank the chemicals of interest in the northerly flowing groundwater, those identified from the screening of the Older Volcanics (section 9.2.1 and Silurian aquifers (section 9.2.2) were compared with the chemicals of interest identified in the Moonee Ponds Creek water (section 10.1) and sediment (section 10.2).

Table 39 shows compares the chemicals of interest identified in the Older Volcanics and Silurian groundwater with those identified in the Moonee Ponds Creek and sediment. The prioritisation of chemicals in the northerly flowing groundwater is discussed in the following sections.

The groundwater data from well MB11 was considered likely to represent background concentrations of inorganic and organic compounds. Well MB11 is located to the north of the Creek, and the hydrogeological model indicates that this well is unlikely to intercept groundwater discharging from the site.

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Table 40. Linkages between Groundwater to north, Creek water and Creek sediment

Groundwater to North Chemicals of Interest Leachate Older

Volcanics Silurian Creek Water

Creek Sediment

TDS Nitrate (as N) Anionic surfactants Cyanide Ammonia (as N) Arsenic Cadmium Copper Iron Mercury Lead Zinc Aluminium Barium Boron Cobalt Total manganese Nickel Selenium Silver Acenaphthylene Acenaphthene Phenanthrene Fluorene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Indeno(1,2,3cd)pyrene Benzo(g,h,i)perylene 1,1-dichloroethene 1,2-dichloroethene Methylethylketone Acetone Carbon disulfide C3 Alkyl benzenes TPHs (C6-C36) Monobutyltin Tripropyltin Aliphatic alkanes Formaldehyde EDTA

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Table 41. Prioritisation of Chemicals of Interest in Northern Groundwater

Chemical Wells / Location Aquifers On-site / Off-site /

Creek



TDS

10006, MB6U, MB9L, MB13, MB23, MB14, MB6L, MB10, MB11, MB12, MPCL07, MPCL08, MPCL09

OV, S On-site and

off-site, Creek water

20,000 3,500 (ABU)

Highest concentrations in MB6U, MB6L (on-site) and MB23 (off-site). Groundwater in wells screened across water-table most affected. Elevated TDS in Creek water opposite site.

High

Nitrate (as N) 10006, MB23, MB10, MB11, MB12 OV, S On-site and

off-site 0.95 0.16 (AEP) Highest concentration in MB11, on the north side of the Creek. Not elevated in Creek Low

Anionic surfactants MB6U, MB9L, MB13, MB23, MB6L, MB24 OV, S On-site and

off-site 0.7 0.14 (AEP) Highest concentrations in MB13. Creek data indicates possible upstream source, however no samples taken in Creek in vicinity of MB13

Med

Cyanide MB6U, MB23 OV On-site and off-site 0.02 0.007 (AEP) Creek data indicates possible up-stream source of

cyanide. Low

Ammonia (as N) 10006, MB6U, MB9L, MB6L, MB10, MB11, MPCL08

OV, S On-site and

off-site, Creek sediment

0.4 0.01 (RW) Detectable concentrations (0.1 mg/L) in MB11. Not detected in the Creek, but high concentrations in Creek sediment . These may be natural

Med

Arsenic MB10 S Off-site 0.014 0.013 (AEP) Exceedence in one off-site well. No exceedences in Creek Low

Cadmium MPCL07, MPCL08 - Creek water 0.001 0.0002 (AEP)

Not found in wells adjacent to Creek. Two exceedences in December not found in January Low

Copper

MB6U, MB9L, MB13, MB23, MB14, MB6L, MB10, MB12, MB24, MPCL08

OV, S On-site, off-

site and Creek water

0.021* / 0.19** 0.0014 (AEP)

Highest concentrations measured in December and in the OV groundwater. Only one exceedence in Creek, but significantly higher than criteria

High

Iron 10006, MB6U, MB6L, MB9L, MB23, MB6L, MB10, MB11, MB24

OV, S On-site and off-site 12 0.3 (RW)

1.0 (I)

Highest concentrations in MB6U and MB6L in October 2003. Not a chemical of interest in the Creek due to upstream concentrations.

Med

Mercury MB13, MB14, MB12 OV, S Off-site 0.014

0.00006 (AEP)

0.001 (RW) 0.002 (I)

0.002 (SW)

Highest concentration in MB13, but duplicate result much lower (0.0015 mg/L). Exceedeces in both aquifers, but also in upstream locations in the Creek.

Med

Lead MPCL08 - Creek water 0.012 0.0034 (AEP)

One exceedence in the Creek at one location only. No exceedences in groundwater wells Low

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Table 41. Prioritisation of Chemicals of Interest in Northern Groundwater contd.


Creek



Zinc

MB6U, MB9L, MB13, MB23, MB14, MB6L, MB10, MB11, MB12, MB24, MPCL07, MPCL08

OV, S On-site and

off-site, Creek water

0.08* / 0.2** 0.008 (AEP)

Widespread exceedences, but also above criteria in MB11 (on north side of Creek) indicating that zinc may be natural component of groundwater. October concentrations overall higher than December for groundwater.

Med

Aluminium MPCL08 - Creek water 0.072 0.055 (AEP) One exceedence at Location 8 only. No exceedences in groundwater. Low

Barium MB23, MB12, MPCL07, MPCL09, MPCL13 OV, S Off-site and

Creek water 0.5* / 0.4** 0.1 (I) Exceedences in two of four wells analysed for barium. May be associated with natural background.

Low

Boron

MB13, MB23, MB14, MB12, MPCL07, MPCL08, MPCL09, MPCL13, MCPL15

OV, S Off-site and Creek water 1.1* / 12**

0.37 (AEP) 1.0 (RW)

0.5 (I)

Widespread exceedences, indicating possible natural background source. Not analysed in well MB11, so natural background cannot be assessed. Creek concentrations two order of magnitude higher than AEP criteria.

Med

Cobalt MB13, MB23, MB12 OV, S Off-site and Creek water 0.5* / 0.012** 0.0014

(AEP)

Widespread exceedences, indicating possible natural background source. Not analysed in well MB11, so natural background cannot be assessed.

Low

Total manganese MB23, MPCL07, MPCL08, MPCL09, MPCL13, MCPL15

OV Off-site and Creek water 2.3* / 6.4**

1.9 (AEP) 0.1 (RW)

0.2 (I)

Widespread exceedences, indicating possible natural background source. Not analysed in well MB11, so natural background cannot be assessed.

Low

Nickel MB13, MB23, M24, MPCL09 OV, S

Off-site and Creek water/

sediment 1.0* / 0.2**

0.011 (AEP) 0.1 (RW)

0.2 (I)

Widespread exceedences, indicating possible natural background source. Not analysed in well MB11, so natural background cannot be assessed. Creek concentrations two order of magnitude higher than AEP criteria.

Med

Selenium MB23, MB12 OV, S Off-site 0.014 0.005 (AEP) Below criteria at all locations in Creek. Exceedences in two wells only. May be associated with natural background.

Low

Silver MB13, MB14, MB12 OV, S Off-site 0.01 0.00005 (AEP)

Consistently detected by Leeder laboratory but not AGAL in paired samples. Leeder detection limit 0.01 mg/L. Possible analytical artefact

Low

PAHs***

MB13, MB23, MB14, MPCL07, MPCL08, MPCL09, MPCL13, MCPL15

OV, S Off-site and Creek water/

sediment

1.1 x 10-5* / 1.2 x 10-4**

2.5 x 10-6 (DL)

Higher concentrations in Creek opposite site. Not analysed in on-site wells or wells MB10 and MB11. No exceedences in well MB12.

High

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Table 41. Prioritisation of Chemicals of Interest in Northern Groundwater contd.


Creek



1,1-dichloroethene MB13 OV Off-site 0.005 0.0003 (RW) Isolated exceedence in one well. Not found in Creek. Low

1,2-dichloroethene MPCL08 - Creek water 0.0018 0.01 – 0.001 (DL) One detection at one location on one occasion. Low

Methylethylketone MB24 S Off-site 0.013 0.01 (DL) Marginal exceedence of detection limit in one well only. Not found in Creek. Low

Acetone MB6U, MB14, MB6L, MB10, MB12 OV, S On-site and

off-site 0.115 0.01 (DL) One exceedence of an order of magnitude above detection limits; remainder only marginally above detection limits. Not found in Creek.

Low

Carbon disulfide MPCL08 - Creek water 0.025 0.01 (DL) One detection at one location on one occasion. Not detected in groundwater. Low

C3 Alkyl benzenes MB23 OV Off-site 0.5 0.1 (DL) One detection at one location on one occasion. Not found in Creek. Low

TPHs (C6-C36) MB23, MB13, MB12, MB24, MPCL07, MPCL09

OV, S Off-site and Creek water 0.75* / 0.72** 0.01 (DL) Highest concentrations in Creek opposite site. Med

Monobutyltin MB24 S Off-site 0.000006 0.000005 (DL)

One detection at one location on one occasion. Not found in Creek. Low

Tripropyltin MB13, MB23, MB12, MB24. All locations in Creek

OV, S

On-site and off-site and

Creek water/ sediment

55 2 (DL) Detectable concentrations in Creek water and groundwater at all locations measured. Med

Aliphatic alkanes MPCL07, MPCL08, MPCL09 - Creek water 0.005 0.001 (DL) Marginal detectable concentrations in Creek

opposite site. Not detected in groundwater. Low

Formaldehyde MB23, MPCL07, MPCL08, MPCL09 OV Off-site and

Creek water 0.04* / 0.48** 0.01 (DL) Highest concentrations opposite Creek , but only at one location on one occasion. Med

EDTA MB13, MB23, MB14, MB24, MB12, MPCL07, MPCL08, MPCL09

OV, S Off-site and Creek water 2.5* / 14** 0.001 (DL) Concentrations two-orders of magnitude higher in

Creek opposite site than up-stream. High

Highest concentrations are those in groundwater unless otherwise indicated. AEP = aquatic ecosystem protection; I = irrigation; RW = recreational water; SW = stock water, DL = detection limit; OV = Older Volcanics; S = Silurian; Med = medium *groundwater; **Creek water ***PAHs considered chemicals of interest were acenaphthylene, acenaphthene, phenanthrene, fluorene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3cd)pyrene, benzo(g,h,I)perylene. Chrysene and benzo(b)fluoranthene were detected in the OV groundwater; pyrene was detected in the S groundwater; the remained of the PAHs listed were detected in the Creek water and have no criteria.

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11.3 Summary of Chemical Prioritisation

The results of the prioritisation of the chemicals of interest shown in Table 39 and Table 41 are summarised in Table 42 below, under the groundwater flow direction in which they were identified.

Table 42. Prioritisation of Chemicals of Interest

Chemical Priority in Southern Groundwater

Priority in Northern Groundwater

TDS Medium High Nitrate Low Low Anionic surfactants Medium Medium Cyanide Low Low Ammonia (as N) Medium Medium Arsenic - Low Chromium (total) Low - Cadmium - Low Copper Medium High Iron Medium Medium Lead - Low Mercury Medium Medium Zinc Medium Medium Aluminium - Low Barium Low Low Boron - Medium Cobalt Low Low Total Manganese Low Low Nickel Low Medium Selenium Low Low Chlorobenzene Low - 1,4-dichlorobenzene Low - 1,2-dichlorobenzene Low - Cresols Low - PCBs (as Aroclor 1254) Medium - PAHs Medium High Bis(2-ethylhexly)phthalate Low -

1,1-dichloroethene - Low 1,2-dichloroethene - Low Toluene Low - Xylenes (m- and o-) Medium - 1,2,4-trimethylbenzene Medium - Carbon disulfide - Low Methylethylketone Low Low Acetone Medium Low C3 alkyl benzenes - Low TPHs (C6 – C36) Medium Medium Monobutyltin - Low Dibutyltin Low - Tripropyltin Medium Medium Aliphatic alkanes - Low Formaldehyde - Medium EDTA Low High “-“ not identified as a chemical of interest from the chemical screening and therefore not ranked for priority

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The intent of the chemical screening and prioritisation was to identify chemicals of interest such that any further monitoring, assessment and modelling work is focussed to only those chemicals considered to pose potential risks to groundwater. As a consequence, chemicals not in detectable concentrations, or not detected at concentrations above criteria can be either removed from further consideration, or at least receive much lower priority in any further assessment and/or monitoring work on the site.

Overall, the chemical screening identified similar chemicals of interest in the northern and southern groundwater, with some exceptions (e.g., chlorinated benzenes and alkenes). This finding is consistent with the presence of a single source of chemicals (i.e., leachate) in the site and site groundwater with similar natural background concentrations of chemicals.

For any given chemical of interest, a higher priority was usually applied to its presence in northern groundwater, rather than southern groundwater, due to the proximity of the Creek to the north.

High priority chemicals were identified as TDS, copper, PAHs and EDTA in the northern groundwater only. All of these chemicals were also identified as chemicals of interest (albeit with different priorities) in the southern groundwater.

A summary of the findings of this preliminary risk assessment and of the recommended future assessment work related to the chemical screening and prioritisation is provided in section 13.0.

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12.0 PRELIMINARY RISK ASSESSMENT (NON-AQUEOUS PHASE) The EPA Licence for the site requires that the preliminary risk assessment “include an assessment of the long-term risk of the aqueous phase and non-aqueous phases (including polychlorinated biphenyls) of leachate migrating offsite.” (EPA 2003a). In subsequent correspondence with the EPA, it was agreed that this should include an assessment of the presence of dense non aqueous phase liquids (DNAPLs). The following sections discuss the risk of non aqueous phase leachate migrating off site.

12.1 Light Non Aqueous Phase Liquid

Figure 10 summarises the information relating to the extent of LNAPL in the leachate as well as in the groundwater both on and off site. The data indicate that: • the LNAPL appears to be located with Mounds 1 and 2 of the landfill. This finding is

consistent with the site’s history in that liquid waste was placed in craters for treatment in the area of the landfill now identified by Mounds 1 and 2. At that time, the northern edge of this landfill area was formed by the original wall of the quarry consisting of Older Volcanics overlain by Brighton Group. This wall ranged in height from about 100 to 110 mAHD (based on a survey plan from 1974) which is higher than the leachate levels typically recorded of between 91 to 95 mAHD LNAPL has not been observed in Mound 3 (e.g., wells T1, T2, T3 and 17). The concentrations of TPHs or other organics that may be indicative of LNAPL in the aqueous phase leachate of Well 17 were typically one to two orders of magnitude lower in than those observed in Mounds 1 and 2 which supports the observations. This also suggests that the original quarry wall may be limiting the ability of the LNPAL to migrate to the north into Mound 3.

Figure 10 indicates that the LNAPL on the leachate does not extend as far north in Mound 2 as wells 11, 12 and 13, which are located to the south of the former bund wall (and compacted clay liner) that was constructed to isolate the landfill from the surrounding environment. Wells 11, 12 and 13, may not have been constructed to detect the presence of LNAPL, however, the leachate levels in these wells have typically been higher than those to the south even following installation and operation of the leachate extraction system. The gradient may have limited the movement of the LNAPL towards the former flood prevention bund.

• LNAPL has not been observed in groundwater monitoring wells either on or off site to the north in the direction of Moonee Ponds Creek. Each monitoring location has at least one well that is screened across the water table and hence is adequate to identify the presence of LNAPL at that location.

• LNAPL has not been observed in groundwater monitoring wells either on or off site to the

south. However, a number of the monitoring wells to the south are not likely to be of suitable construction for monitoring the presence of LANPL due to the position of the

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well screen with respect to the water table. TPHs, naphthalene and some aromatics such as benzene, ethylbenzene and xylenes have been observed in monitoring well MB22 and lower concentrations in monitoring well MB21 to the south west. While this may indicate that dissolved phase from LNAPL may be migrating in this direction, it is important to note that:

1. the concentrations of these chemicals in the second round of sampling were typically much less than in the first round of sampling.

2. the level of water in MB22 has been reducing overtime and as such it is suspected that this well may not be reliable and may be being impacted by surface water runoff (see Section 6.3.3).

In the south-east direction, the PCB Aroclor 1254 has been detected in monitoring wells MB15 and MB17. The concentrations of other, more mobile, organics such as TPH and aromatics are either not detectable or are generally at concentrations just above the detection limit in these wells. The TDS in monitoring well MB17 is much lower than that observed in the leachate and is close to background water quality. This observation suggests that this well MB17 is not significantly impacted by migration of leachate from the landfill. Hence, it is not clear whether the PCBs have originated from the landfill leachate. In addition, monitoring wells MB15 and MB16 are screened across the water table and LNAPL has not been observed. Therefore, it is unlikely that LNAPL is in close proximity to wells MB15 and MB16. However, since the monitoring wells, Tulla3L, Tulla3U, MB4L, MB4U and 10005 are all screened below the water table it is not possible to establish whether LNAPL has migrated from the landfill to the groundwater.

In summary, the extent of LNAPL migration, possibly off site, to the south and south west is not defined and hence further work is required.

At all but one of the groundwater monitoring locations beyond the site boundary, (location of wells MB21 and MB22) there is a well that screens across the water table. The data suggest that LNAPL from the site is not migrating into Moonee Ponds Creek and that it does not extend beneath land where extraction of groundwater could occur, notwithstanding that such extraction is unlikely. This indicates that people and/or the surface water environment are not likely to come into contact with the LNAPL and hence the risks are considered to be low. In order to ensure that this risk remains low in the longer term:


• the network of wells on the site boundary and off site should continue to be monitored for the presence of LNAPL. The frequency of such monitoring would need to be agreed with the EPA but is unlikely to need to exceed once every year.

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12.2 Dense Non Aqueous Phase Liquid Dense non aqueous phase liquids (DNAPLs) differ from LNAPLs in that they are heavier than water and can migrate downward through the groundwater. Due to this characteristic it is rare to observe DNAPLs within groundwater wells other than is the dissolved phase. Chemicals that can form DNAPLs include chlorinated hydrocarbons, PCBs and coal tars. A generally adopted assumption is that is if a compound is detected at greater than 1% of its theoretical solubility limit (adjusted for its mole fraction in the DNAPL mixture) then DNAPL is likely to be present in groundwater (Pankow and Cherry 1996).

Table 43 compares the aqueous phase concentrations of DNAPLs that have been detected in the leachate and groundwater with literature based solubilities. The table demonstrates that even the concentrations within the leachate are much less than 1% of the solubility and often by many orders of magnitude. The exception to this is the PCB, Aroclor 1254, where the concentration measured in the leachate exceeds the solubility. PCBs are known to be present in the LNAPL and the only concentrations above the laboratory detection limit were in wells where LNAPL is known to be present. Based on this, the detected concentrations of PCBs most likely represent an artefact of contamination from the overlying LNAPL during sampling and are not indicative of the presence of a DNAPL.

The groundwater monitoring wells are positioned around the site and in most locations there are a range of wells that screen the groundwater system at a range of depths. The concentrations in the groundwater of the chemicals that have the potential to form DNAPL are significantly less than 1% of solubility. Therefore, based on the data for leachate and groundwater, it is considered unlikely that there is DNAPL migrating from the site.

Table 43. Comparison of Solubility of DNAPL Chemicals to Leachate and Groundwater Quality

Concentration Range (mg/L) Chemical / Parameter

Literature Solubility

(mg/L) Leachate Northerly Wells Southerly

Wells

Vinyl Chloride 2,760 <0.001 – 5.3 <0.001 - <0.01 <0.01 – 0.04

1,1-Dichloroethene 3,350 <0.001 - <0.1 <0.001 – 0.005 <0.001

trans-1,2-Dichloroethene 3,500 <0.001 – 0.1 <0.001 - 0.003 <0.001 - 0.006

cis-1,2-Dichloroethene 6,300 <0.001 – 2.6 <0.001 - 0.02 <0.001 - 0.02

1,1-Dichloroethane 5,100 <0.001 – 0.16 <0.001 – 0.02 <0.001 – 0.03

1,2 – Dichloroethane 8,500 <0.001 - <0.02 <0.001 – 0.02 <0.001 – 0.03

Trichloroethene 1,100 <0.001 – 0.11 <0.001 – 0.02 <0.001 – 0.007

1,1,2-Trichloroethane 4,400 <0.001 – 0.02 <0.001 – 0.009

Chlorobenzene 500 <0.001 – 0.16 <0.001 – 0.05 <0.001 – 0.09

Aroclor 1254 0.057 <0.005 – 0.1 <0.000001 <0.000001 – 0.000016

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13.0 SUMMARY

13.1 Approach

The aims of this preliminary risk assessment were to

1. assess whether groundwater quality objectives as specified in State Environment Protection Policy (Groundwaters of Victoria) are being met at the premises; and

2. include an assessment of the long-term risk of the aqueous phase and non-aqueous phases (including polychlorinated biphenyls) of leachate migrating offsite.” (EPA 2003a)

The approach undertaken to meet these aims involved:

• development of a hydrogeological conceptual model to identify leachate and groundwater flow directions and discharge points;

• assessment of the ecological condition of the Moonee Ponds Creek;

• identification of appropriate chemical screening criteria for groundwater, surface water and sediment based on the requirements of Victorian legislation;

• screening and assessment of chemical data from the groundwater, surface water and sediment that were collected over the period October 2003 to January 2004 and identification of chemicals of interest in northern and southern groundwater;

• prioritisation of the chemicals of interest as either low, medium or high priority for further assessment, monitoring and/or management; and

• assessment of the data collected from leachate wells over the period 1999 – 2003 to evaluate the extent and possible risks of migration of LNAPLs and DNAPLs from the landfill.

In summary, to assist in addressing the preliminary risk assessment aims, chemical data from 28 groundwater wells, 19 leachate wells and seven Moonee Ponds Creek water and sediment sampling locations were analysed for up to 218 chemical analytes1.

13.2 Findings

The evaluation of the available data indicate: 13.2.1 Aqueous Phase

• Aqueous phase leachate is impacting on groundwater that is migrating away from the site.

• Some groundwater quality objectives are not being met at the premises and at some locations off the premises.

• Of the 218 chemicals analysed in groundwater, surface water and sediment, 43 were identified as “chemicals of interest” that may require further assessment, monitoring and/or management. The remaining chemicals were found to have concentrations below

1 Not all chemical analytes were analysed in all wells or all Creek sampling locations.

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their respective criteria and/or detection limits and were therefore considered to pose negligible risks to the beneficial uses of groundwater.

• Four (4) of the 43 chemicals of interest were identified as “high priority” on the basis of the degree of exceedence of criteria, spatial and temporal extents of exceedences, and the proximity of existing beneficial uses (e.g., the Moonee Ponds Creek to the north of the site). Fourteen (14) chemicals of interest were identified as “medium priority”, and the remainder of the chemicals of interest were identified as “low priority”.

13.2.2 Non-Aqueous Phase

There is no evidence of free-phase (LNAPL) in the off-site wells, although it is noted that some wells are not screened in a manner that enables observation of free-phase. The data suggest that LNAPL from the site is not migrating into Moonee Ponds Creek and it does not extend beneath land where extraction of groundwater could occur, notwithstanding that such extraction is unlikely. This indicates that people and/or the surface water environment are not likely to come into contact with the LNAPL and hence the risks are considered to be low.

The concentrations of chemicals in the groundwater and leachate do not suggest that DNAPL is present on the site or migrating from the site.

13.3 Conclusions Golder Associates has carried out a preliminary risk assessment with respect to the potential impact to surface and ground waters associated with the landfilling activities at the site. A broad range of chemicals that have been identified within the landfill leachate have also been analysed in groundwater emanating from the site as well as within the surface waters of Moonee Ponds Creek. Only a limited number of chemicals have been identified as having a high potential to impact the quality of the Creek. The potential for impact of these chemicals on the Creek requires further evaluation. The concentrations of chemicals measured within the groundwater are typically low, and while some of these exceed criteria for specific beneficial uses, there has been limited impact from the landfill on groundwater beyond the boundaries of the site.

In relation to the aims of the preliminary risk assessment, as set out in Condition 2.41 of the EPA Licence for the site:

1. some groundwater quality objectives are not being met at the premises;

2. aqueous phase leachate is impacting on groundwater that is migrating away from the site and further assessment, monitoring and/or management of groundwater is required with respect to the identified chemicals of interest; and

3. non-aqueous phase liquids (LNAPL or DNAPL) have not been detected migrating off the site. Ongoing monitoring will be required to ensure that the long term risk to people and the environment remains low.

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14.0 RECOMMEDATIONS

This preliminary risk assessment has identified a range of recommended actions that need to be further defined and implemented by the management plan as required by clause 2.44 of the licence (EPA 2003a). These recommendations are summarised below. 14.1 Aqueous Phase

Aqueous phase impact to groundwater should be addressed in accordance with the prioritisation of the chemicals of interest, as follows: • High priority chemicals of interest - require further evaluation including monitoring,

fate and transport modelling and/or a quantitative risk assessment.

• Medium priority chemicals of interest require management through monitoring and administrative controls but may also require further evaluation of fate and transport if future monitoring suggests trends of increasing risk.

• Low priority chemicals of interest may require no further evaluation other than an assessment of whether they should be included in the ongoing monitoring program for the site.

• Chemicals not identified as chemicals of interest may require no further monitoring, other than a final confirmatory groundwater and Creek sampling round.

These prioritised actions should be addressed by a supplementary risk assessment. The aims of the supplementary risk assessment would be to establish which, if any, of the chemicals of interest pose risks to the existing beneficial uses of groundwater such that appropriate management actions can be implemented to mitigate the risks. In order to achieve this, the supplementary risk assessment of groundwater should involve a combination of one or more of the following:

1. Low, Medium and High Priority

• Finding, and assessing for suitability, criteria for surface water and groundwater for the chemicals of interest that have been identified on the basis of detectable concentrations only (i.e., no relevant State or National criteria were available). Agreement on the criteria will need to be reached with EPA.

• Assessing and comparing data on background groundwater quality with the concentrations of those chemicals considered to be natural background groundwater conditions. These chemicals are considered to be the inorganics barium, boron, cobalt, iron, total manganese and selenium.

• Sampling of groundwater and/or the Moonee Ponds Creek for those chemicals of interest identified on only one monitoring occasion or only at one location to confirm (or otherwise) the existing results;

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2. High Priority Only

• Ecological risk assessments of those chemicals of interest potentially posing risks to aquatic ecosystems in the Moonee Ponds Creek. The risk assessments may involve a combination of literature data and site-specific sampling and toxicological testing.

14.2 Non Aqueous Phase

In order to ensure that this risk associated with LNAPL migration remains low in the longer term:


• the network of wells on the site boundary and off site should continue to be monitored for the presence of LNAPL The frequency of such monitoring would need to be agreed with the EPA but is unlikely to need to exceed once every year.

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15.0 REFERENCES

ANZECC (1992). Australian and New Zealand Environment Conservation Council. Australian Water Quality Guidelines for Fresh and Marine Waters. National Water Quality Monitoring Strategy. November 1992.

ANZECC and ARMCANZ (2000). Australian and New Zealand Environment Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand. Australian and New Zealand Guidelines for Fresh and Marine Water Quality. National Water Quality Monitoring Strategy. October 2000.

Coleman R. (1999). Melbourne Water Healthy Waterways. Waterways Report 1998. Health of Waterways within the Port Phillip and Western Port Catchments.

EPA (2003a). Environment Protection Authority Victoria. Licence to Brambles Australia Limited Trading as Cleanaway. Licence Number HS346, issued 2 October 1973 and last amended 21 October 2003.

EPA (2003b). Environment Protection Authority Victoria. Letter to Cleanaway Melbourne Landfills, dated 17 June 2003, Reference 11967.

Golder (1975). Golder Associates Pty Ltd. Industrial Waste Collection Groundwater Observation and Monitoring to January 1975 at the Industrial Solid and Liquid Waste Disposal Site at Bayview Quarry, Tullamarine, dated February 1975.

Golder (1981). Geotechnical Investigatio, South-West Corner, Bayview Quarry, Tullamarine, Golder Reference No 4797, dated May 1981

Golder (1994). Golder Associates Pty Ltd. Groundwater Chemistry Data Review, Tullamarine Waste Disposal Site, Tullamarine, dated May 1994.

Golder (1998). Golder Associates Pty Ltd. Report on Feasibilty of Extension to Tullamarine Landfill Tullamarine, Victoria, March 1998.

Golder (2000). Golder Associates Pty Ltd. Impact of Tullamarine Waste Disposal Site on Groundwater and Surface Water. Report for Cleanaway Landfill Branch, dated April 2000.

Golder (2001). Golder Associates Pty Ltd. Installation of Groundwater Wells, Moonee Ponds Creek, Tullamarine Waste Disposal Facility, Tullamarine, Golder reference 98613650/134, dated February 2001

Golder (2002). Golder Associates Pty Ltd. Off-site Groundwater Monitoring and Risk Assessment Methodology, Tullamarine Waste Disposal Site. Report for Cleanaway Melbourne Landfills, dated February 2002.

Golder (2003). Golder Associates Pty Ltd. Letter to Cleanaway Melbourne Landfills dated May 6. Golder reference 02613641/023.

GoV (1997). Government of Victoria. State Environment Protection Policy Groundwaters of Victoria. Victoria Government Gazette S160. 17 December 1997.

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GoV (1999). Government of Victoria. Variation of State Environment Protection Policy (Waters of Victoria) – Insertion of Schedule F7. Waters of the Yarra Catchment. Victoria Government Gazette S89. 22 June 1999.

GoV (2003). Government of Victoria. State Environment Protection Policy Waters of Victoria. Victoria Government Gazette S107. 4 June 2003.

Ho J. and Pettigrove V. (1996). The Water Quality of Moonee Ponds Creek, Catchment and Drainage Branch, Melbourne Water.

Long E.R., MacDonald D.D., Smith S.L. and Calder E.D. (1995). Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments. Environment Management 19: 81-97.

Muir, A.M. and Bezuijen, M.R. (1998). Airport Rail Link Preliminary Biological Study: Broadmeadows Route, for the Department of Infrastructure by Ecology Australia Pty. Ltd.

NEPC (1999). National Environment Protection Council Service Corporation. National Environment Protection (Assessment of Site Contamination) Measure. Adelaide, SA.

Pankow J.F. and Cherry J.A. (1996). Dense Chlorinated Solvents and other DNAPLs in Groundwater: History, Behaviour. And Remediation. Waterloo Press.

Raadik T.A. (1999). A Brief Assessment of Aquatic Biota at Selected Sites in the Upper Moonee Ponds Creek. Department of Natural Resources and Environment for Parks Victoria.

Shugg A. (1975): Progress Report on the Hydrogeology of the Tullamarine Liquid Waste Disposal Site, Geological Survey of Victoria, 23 April 1975

Shugg A. (1979). Exanimation of a liquid Waste Disposal Site at Tullamarine, Proc. Groundwater Pollution Conference, Perth 1979 (AWRC) 21-25 November 1994.

Shugg A. (1994). Landfill Co-Disposal of Liquid and Non-Putrescible Industrial Waste, Tullamarine. A Case Example. Water Down Under Conference, Adelaide, Australia, 21-25 November 1994.

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16.0 LIMITATIONS OF THIS REPORT

This report has been prepared in accordance with the agreement between Cleanaway and Golder Associates Pty Ltd. The services performed by Golder Associates have been conducted in a manner consistent with the level of quality and skill generally exercised by members of its profession and consulting practice. No warranty or guarantee of site conditions is intended.

This report is solely for the use of Cleanaway and any reliance of this report by third parties shall be at such party’s sole risk and may not contain sufficient information for purposes of other parties or for other uses. This report shall only be presented in full and may not be used to support any other objective than those set out in the report, except where written approval with comments are provided by Golder Associates.

The information on subsurface conditions in this report is considered to be accurate at the date of issue in accordance to the current conditions of the site. Subsurface conditions can vary across a particular site which cannot be explicitly defined by investigation. Therefore, it is unlikely that the results and estimations expressed in this report will represent the extremes of conditions within the site. Subsurface conditions including contaminant concentrations can change in a limited period of time. This should be considered if the report is used after a significant delay in time.

Attached as Appendix J is a document entitled "Important Information About Your Environmental Site Assessment" which should be read in conjunction with this report. We would be pleased to answer any questions about this important information.

GOLDER ASSOCIATES PTY LTD

Carolyn Brumley Jonathan Medd Senior Environmental Scientist Associate

Irene Krusic-Hrustanpasic Roger Parker Senior Hydrogeologist Principal CMB/RJP/cmb/641w046r.doc

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FIGURES

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APPENDIX A

EPA Licence HS346

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APPENDIX B

Copies of Borelogs

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Notes to Borelogs Borelogs 97005R and 97007 were generated from drillers’ logs of the Department of Energy and Minerals, provided by SKM and the Groundwater Management System “Site Details Report”. The logs were not generated by Golder Associates’ engineers.

Borelogs 10,005, 10,006, MB4B (MB4LB) and Tulla3U and Tulla3L (Tullamarine 3) were copied from historical reports. The logs were not generated by Golder Associates’ engineers.

Borelogs BH1, BH2 and BH3 were sourced from historical reports and were generated by Golder Associates’ engineers.

Borelogs MB6U and MB6L were not available for this report.

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APPENDIX C

Leachate Data (1999 – 2002)

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APPENDIX D

Groundwater Data (October and December 2003)

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APPENDIX E

Moonee Ponds Creek Data (December 2003 and January 2004)

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APPENDIX F

Copies of Laboratory Reports

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APPENDIX G

Assessment of Data Quality

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APPENDIX H

Copies of Kingtech Field Sampling Records

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APPENDIX I

Groundwater Wells in Area

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APPENDIX J

IMPORTANT INFORMATION ABOUT YOUR ENVIRONMENTAL SITE ASSESSMENT

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