Mihaljevic Constructions Pty Ltd · Environmental Audit Report 37 Orion Street (rear), Sebastopol,...

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Environmental Audit Report

37 Orion Street (rear), Sebastopol, Victoria

for

Mihaljevic Constructions Pty Ltd

October 2007

Ref: 32-0054

Audit PWH-VIC-013

www.environcorp.com

23 October 2007 Our Ref: 32-0054

Att: Alan Mihaljevic Mihaljevic Constructions Pty Ltd C/O Beveridge Williams & Co. Pty Ltd Suite 6, 115 Hawthorn Road Caulfield North, Victoria, 3161

Dear Alan,

Re: Site Audit Report – 37 Orion Street (rear), Sebastopol, Victoria

This Environmental Audit Report and attached Statement of Environmental Audit present the findings of an Environmental Audit undertaken for the property located at 37 Orion Street (rear), Sebastopol, Victoria (the Site). The Audit was undertaken in accordance with Part IXD of the Environment Protection Act (1970). The Environmental Audit Report and Statement of Environmental Audit were completed in accordance with the guidelines issued by the EPAV for environmental audit of contaminated sites as well as relevant Victorian State Environmental Protection Policies.

The Audit was commissioned by Alan Mihaljevic of Mihaljevic Constructions Pty Ltd to assess the suitability of the Site for its intended low density residential use.

The Audit was requested by Ballarat City Council as the site is covered by Environmental Audit Overlay

Thank you for giving me the opportunity to conduct this Audit. Please call me on (02) 4934 4354 if you have any questions.

Yours faithfully,

ENVIRON Australia Pty Ltd

Phillip Hitchcock Environmental Auditor (appointed pursuant to the Environment Protection Act 1970)

Suite 2, Level 1, 456 High St, PO Box 564, Maitland, NSW 2320 Tel: +61.2.4934.4354 Fax: +61.2.4934.4359 ENVIRON Australia Pty Ltd (ACN 095 437 442; ABN 49 095 437 442)

CERTIFICATE OF ENVIRONMENTAL AUDIT ENVIRONMENT PROTECTION ACT 1970

CERTIFICATE OF ENVIRONMENTAL AUDIT

I, Phillip William Hitchcock of Environ Australia Pty Ltd, a person appointed by the Environment Protection Authority (‘the Authority’) under the Environment Protection Act 1970 (‘the Act’) as an environmental auditor for the purposes of the Act, having:

1) been requested by Mr Alan Mihaljevic of Mihaljevic Construction Pty Ltd to issue a certificate of environmental audit in relation to the Site located at rear No 37 Orion Street, Sebastopol, Lot S2 on PS604704V, Volume 11023, Folio 330, City of Ballarat owned by Mihaljevic Construction Pty Ltd.

2) had regard to, among other things,

I. guidelines issued by the Authority for the purposes of Part IXD of the Act, II. the beneficial uses that may be made of the site, and

III. relevant State environment protection policies/industrial waste management policies, namely

• State Environment Protection Policy (Air Quality Management) • State Environment Protection Policy (Waters of Victoria) • State Environment Protection Policy (Groundwaters of Victoria) • State Environment Protection Policy (Prevention and Management of

Contaminated Land) • Industrial Waste Management Policy (Prescribed Industrial Waste).

in making a total assessment of the nature and extent of any harm or detriment caused to, or the risk of any possible harm or detriment which may be caused to, any beneficial use made of the site by any industrial processes or activity, waste or substance (including any chemical substance), and

3) completed an environmental audit report in accordance with section 53X of the Act, a

copy of which has been sent to the Authority and the relevant planning and responsible authority.

HEREBY CERTIFY that I am of the opinion that the condition of the site is neither detrimental nor potentially detrimental to any beneficial use of the site. This Certificate forms part of environmental audit report (Environ Australia, Rear 37 Orion Street, Sebastopol, Victoria, Report No. 32-0054, 23rd October 2007). Further details regarding the condition of the site may be found in the environmental audit report. DATED Tuesday October 23, 2007 Signed

Environmental Auditor (appointed pursuant to the Environment Protection Act 1970)

23 / IA l2AA7 ILz29 +613 -5333 -2644

Deliveredby LANDATA@, Land Registry timestamp 3l/08/2007 09;15

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Mihaljevic Constructions Pty Ltd October 2007 37 Orion Street (rear), Sebastopol, Victoria Page 1

Table of Contents

1. INTRODUCTION ...............................................................................................................1

1.1. General ......................................................................................................................1

1.2. Site Identification and Audit Details.........................................................................1

1.3. Background and Proposed Development ..................................................................2

1.4. Audit Scope...............................................................................................................2

2. CONTAMINATION INVESTIGATION WORKS SUBJECT TO AUDIT.......................3

2.1. CCG (2000)...............................................................................................................3

2.2. BW (2006/2007) .......................................................................................................3

3. SITE CONDITION AND SURROUNDING ENVIRONMENT ........................................5

3.1. Site Condition ...........................................................................................................5

3.2. Adjacent Uses and Offsite Contamination Sources ..................................................6

3.2.1. Surrounding Property Use ...........................................................................6

3.2.2. Nearby Environmental Audits .....................................................................6

3.3. Sensitive Receptors ...................................................................................................7

BW has not identified sensitive receptors. The Auditor has identified the following sensitive receptors: .............................................................................................................7

Future Site users;.......................................................................................................7

Users of surrounding residential properties; .............................................................7

Users and ecosystems of the Yarrowee River, located approximately 200m to the east of the Site. The audit at the front of Orion Street also identified a small tributary of Yarrowee River located to the south of the site, as the nearest receptor............................7

3.4. Auditor’s Site Inspection ..........................................................................................7

3.5. Auditor’s Conclusion Regarding Site Condition Information ..................................7

4. SITE HISTORY...................................................................................................................8

4.1. Available Site History Information...........................................................................8

4.2. Auditor’s Conclusions Regarding Site History Data ................................................8

5. AREAS AND CONTAMINANTS OF CONCERN............................................................9

S:\Environ\Jobs\VICTORIA AUDITS\Mihaljevic Constructions - Sebastopol 32-0054\Report\32-0054 Environmental Audit Report Final.doc ENVIRON


5.1. Identified Areas and Contaminants of Concern ........................................................9

5.2. Auditor’s Conclusion Regarding Identified Areas and Contaminants of Concern ...9

6. GEOLOGY AND HYDROGEOLOGY ............................................................................10

6.1. Regional Geology ...................................................................................................10

6.2. Site Specific Geology..............................................................................................10

6.3. Regional Hydrology and Hydrogeology .................................................................10

6.4. Site Specific Hydrogeology ....................................................................................11

6.5. Auditors Conclusion Regarding Geology and Hydrogeology Data........................11

7. EVALUATION OF QUALITY ASSURANCE AND QUALITY CONTROL................12

7.1. Review of Consultants Data....................................................................................12

7.2. Investigation Adequacy...........................................................................................13

7.2.1. Review of Sampling and Analysis Methodology ......................................13

7.3. Data Usability .........................................................................................................14

8. ENVIRONMENTAL QUALITY CRITERIA...................................................................15

8.1. General ....................................................................................................................15

8.2. Soil ..........................................................................................................................15

8.2.1. Protection of Human Health ......................................................................15

8.2.2. Protection of the Environment...................................................................15

8.2.3. Buildings and Structures............................................................................15

8.2.4. Aesthetics ..................................................................................................16

8.2.5. Production of Food, Flora and Fibre..........................................................16

8.3. Groundwater ...........................................................................................................16

8.3.1. Protection of Ecosystems...........................................................................16

8.3.2. Protection of Human Health – Potable Drinking Water ............................17

8.3.3. Protection of Human Health – Potable Mineral Water..............................17

8.3.4. Protection of Human Health – Agriculture, Parks and Gardens................17

8.3.5. Protection of Livestock..............................................................................17



8.3.6. Industrial Water Use..................................................................................17

8.3.7. Protection of Human Health – Primary Contact Recreation......................18

8.3.8. Buildings and Structures............................................................................18

8.4. Criteria Used by BW...............................................................................................18

9. EVALUATION OF SOIL ANALYTICAL RESULTS & SOIL REMEDIATION WORKS .............................................................................................................................19

9.1. Summary of Soil Investigation Results (CCG 2000)..............................................19

9.2. Summary of Soil Investigation Results (BW 2006)................................................19

9.3. Soil Remediation Works .........................................................................................21

9.3.1. Soil Remediation Approach.......................................................................21

9.3.2. Assessment of Remediation and Validation Activities..............................21

9.4. Auditor’s Verification Sampling Results ................................................................26

9.5. Summary of Remnant Soils ....................................................................................26

9.6. Beneficial Uses Assessment - Soils .......................................................................27

9.7. Implication of Remnant Soil Analytical Results – Impact to Beneficial Uses .......28

9.7.1. Ecosystem maintenance.............................................................................28

9.7.2. Human health.............................................................................................30

9.7.3. Buildings and structures ............................................................................31

9.7.4. Aesthetics ..................................................................................................31

9.7.5. Production of food, flora and fibre ............................................................31

9.8. Implication of Soil Analytical Results – Offsite Migration ....................................31

10. EVALUATION OF GROUNDWATER ANALYTICAL RESULTS ..............................32

10.1. Beneficial Uses Assessment....................................................................................32

10.2. Relevance of Beneficial Uses .................................................................................33

10.3. Summary of Groundwater Analytical Results ........................................................34

10.4. Implication of Groundwater Results – Impact to Relevant Beneficial Uses..........36

Based on the review of the benefical uses in section 10.2 the only one considered to be relevant was Maintenance of Ecosystems and this is discussed below............................36



10.4.1. Maintenance of Ecosystems ......................................................................36

10.5. Note Regarding Inappropriate PQL’s .....................................................................37

10.6. Clean Up to the Extent Practical CUTEP ...............................................................38

11. CONCLUSIONS AND RECOMMENDATIONS ............................................................39

12. OTHER RELEVANT INFORMATION ...........................................................................40



LIST OF TABLES AND FIGURES

Table 1.2.1 – Site Identification .................................................................................................1

Table 1.2.2 – Audit Details.........................................................................................................1

Table 4.1 – Site History Summary .............................................................................................8

Table 5.1.1 – Areas and Contaminants of Concern....................................................................9

Table 6.2.1 – Generalised Site Specific Geology.....................................................................10

Table 6.4.1 – Site Specific Hydrogeology................................................................................11

Table 9.3.2.1 Summary of Remediation and Validation Works (28/11/06 to 8/3/07) .............22

Table 9.5.1 Summary of Key Contaminants of Concern in Remnant Soils .............................26

Table 9.6.1 Beneficial Uses to be protected based on land use (after table 1, SEPP Prevention and Management of Contamination of Land). ...................................................................27

Table 9.6.2 – Indicators and Objectives for Beneficial Land Uses (modified from SEPP 2002) ..........................................................................................................................................28

Table 9.7.1.1 Summary of EIL Exceedances (Remnant Soils) ................................................29

Table 10.1.1 - Protected Beneficial Uses of Groundwater (reproduced from SEPP 1997)......32



LIST OF APPENDICES

Appendix A Attachment 1: Site Location Plan

Attachment 2: Site Survey Plan

Attachment 3: Site Redevelopment Plan

Attachment 4: Site Features and Sampling Location Plans

Appendix B Coomes Consulting Group Pty Ltd (August 2000) Report for Pinnacle Property Group on Preliminary Site Assessment, Former VicRoads Depot Site, 37 Orion Street, Sebastopol (ref: 6977)

Appendix C Letter from Mr.Ian Mckenzie of Beveridge Williams & Co. Pty Ltd to Mr. Phillip Hitchcock of Environ Australia Pty Ltd titled ‘Procedure for Remediation Works, Rear of 37 Orion Street, Sebastopol’, dated 21 November 2006

Appendix D Beveridge Williams & Co. Pty Ltd (July 2007) Contamination Assessment, Remediation and Validation Works, Rear of 37 Orion Street, Sebastopol (Ref: D3461)

Appendix E Review of Quality Assurance / Quality Control

Appendix F EPAV letter regarding waste disposal




List of Abbreviations AHD Australian Height Datum ALS Australian Laboratory Services ASET Australian Safer Environment and Technology Pty Ltd. (Laboratory) ANZECC Australian and New Zealand Environment and Conservation Council BaP Benzo(a)pyrene BGL below ground level BTEX Benzene, Toluene, Ethylbenzene & Xylenes (Monocyclic aromatic Hydrocarbons) CHC Chlorinated Hydrocarbons CN Cyanide (total or free) CT Certificate of Title DP Deposited Plan DQO Data Quality Objectives EPAV Environment Protection Authority Victoria ESA Environmental Site Assessment report ha Hectare km Kilometres LOR Limit of Reporting m Metres MAH Monocyclic Aromatic Hydrocarbons Mercury Inorganic mercury unless noted otherwise Metals Arsenic, Cadmium, Chromium, Copper, Nickel, Lead, Zinc, Mercury Metals (13) Arsenic, Cadmium, Chromium, Copper, Nickel, Lead, Zinc, Mercury, Antimony, Barium,

Beryllium, Cobalt, Manganese, Molybdenum, Selenium, Tin. mg/kg Milligrams per Kilogram mg/L Milligrams per Litre m BGL Metres below ground level mg/L Micrograms per Litre NATA National Association of Testing Authorities NC Not Calculated ND Not Detected ng/L Nanograms per Litre NEHF National Environmental Health Forum NEPM National Environment Protection Measure NHMRC National Health and Medical Research Council n Number of Samples OCPs Organochlorine Pesticides OH&S Occupational Health & Safety OPPs Organophosphorus Pesticides PAHs Polycyclic Aromatic Hydrocarbons PCBs Polychlorinated Biphenyls PID Photoionisation Detector PQL Practical Quantitation Limit pH a measure of acidity, hydrogen ion activity QA/QC Quality Assurance/Quality Control RPD Relative Percent Difference SILs Soil Investigation Levels SVOCs Semi Volatile Organic Compounds TPHs Total Petroleum Hydrocarbons UCL Upper Confidence Limit VENM virgin excavated natural material VHC Volatile Halogenated Compounds VOCs Volatile Organic Compounds - On tables is "not calculated", "no criteria" or " not applicable"


1. INTRODUCTION

1.1. General

This Environmental Audit Report and attached Certificate of Environmental Audit present the findings of an Environmental Audit undertaken for the property located at 37 Orion Street (rear), Sebastopol, Victoria (the Site). The Audit was undertaken in accordance with Part IXD of the Environment Protection Act (1970). The Environmental Audit Report and Certificate of Environmental Audit were completed in accordance with the guidelines issued by the EPAV for environmental audit of contaminated sites as well as relevant Victorian State Environmental Protection Policies.

1.2. Site Identification and Audit Details

Table 1.2.1 presents a summary of the Site identification and Table 1.2.2 presents the details of the Audit.

Table 1.2.1 – Site Identification

Site Address 37 Orion Street (rear), Sebastopol, Victoria (see Attachment 1, Appendix A)

Identifier Lot S2 on Plan of Subdivision PS604704V Volume 11023 Folio 330 (see Survey Plan in Attachment 2, Appendix A)

Municipality Ballarat

Site Zoning Residential Mixed Use Zone

Site Area Approximately 28,370m2

Latitude/Longitude 5 836 170 N; 751 260 E

Table 1.2.2 – Audit Details

Name of Auditor Phillip Hitchcock

Date Audit Requested 20/09/06

Audit Purpose To assess the suitability of the Site for residential use.

Audit Requirement The Audit was required due to an Environemental Audit Overlay covering the site.

Owner of the Site Mihaljevic Constructions Pty Ltd

Person requesting Audit Alan Mihaljevic

Consultant/s to Site Owner

Coomes Consulting Group Pty Ltd (2000) and Beveridge Williams & Co. Pty Ltd (2006/2007)

Audit Completion Date 23 October 2007



1.3. Background and Proposed Development

It is understood that the Client is intending to develop the Site for residential purposes. The Site will be subdivided into 41 residential lots (average lot size of 556m2) as well as a number of roadways. A layout plan for the proposed redevelopment works at the Site is presented in Attachment 3, Appendix A.

The Site has predominantly been utilised by VicRoads and more recently a number of private companies for plant/machinery maintenance, repair and refuelling as well as goods storage and bitumen batching. These activities may have resulted in the contamination of a number of segments of the environment at the Site. Contamination related investigations have been undertaken at the Site by Coomes Consulting Group Pty Ltd (CCG) during 2000 and Beveridge Williams & Co. Pty Ltd (BW) during 2006/2007.

1.4. Audit Scope

The scope of the Audit included:

Review of the following reports and correspondence:

- Coomes Consulting Group Pty Ltd (August 2000) Report for Pinnacle Property Group on Preliminary Site Assessment, Former VicRoads Depot Site, 37 Orion Street, Sebastopol (ref: 6977) (see Appendix B);

- Letter from Mr. Ian Mckenzie of Beveridge Williams & Co. Pty Ltd to Mr. Phillip Hitchcock of Environ Australia Pty Ltd titled ‘Procedure for Remediation Works, Rear of 37 Orion Street, Sebastopol’, dated 21 November 2006 (see Appendix C);

- Beveridge Williams & Co. Pty Ltd (September 2007) Contamination Assessment, Remediation and Validation Works, Rear of 37 Orion Street, Sebastopol (Ref: D3461) (see Appendix D).

A Site visit by the Auditor, 15 February 2007, 17 March 2007 and 11 June 2007.

Discussions with the Client and BW.



2. CONTAMINATION INVESTIGATION WORKS SUBJECT TO AUDIT

2.1. CCG (2000)

CCG undertook a preliminary contamination assessment at the Site, as well as the adjacent property also located at 37 Orion Street, Sebastopol (fronting Orion Street, adjacent to western boundary of Site) comprising:

Soil sampling from 20 locations within the Site, with samples collected to a maximum depth of 1.2m using a Geoprobe;

Analysis of 20 composite samples (comprising samples collected from 0m to 0.5m from each sampling location) for Heavy Metals (combination of As, Be, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se, Sn & Zn), TPH, BTEX, Total Phenolics, PCB, PAH and VOC; and

Analysis of 18 samples from a depth of 1m for selected Heavy Metals.

The results of the investigations indicated that Heavy Metals (combination of Arsenic, Chromium, Copper, Nickel and Zinc) were present at a number of locations at concentrations exceeding the ANZECC (1992) protection of the environment based guidelines but below the NEPM (1999) protection of human health based guidelines for residential use. CCG concluded that the Site would be suitable for residential uses subject to waste classification and offsite disposal of a materials located within a waste soil and bitumen stockpile area where staining and free product was observed (it is noted that this was on the front part of the site which is not included in the current audit area).

2.2. BW (2006/2007)

BW undertook soil and groundwater investigations at the Site during 2006, comprising:

Soil sampling from 31 boreholes drilled at targeted locations across the Site to refusal on weathered rock (maximum depth of 2.8m);

Soil sampling from two boreholes drilled using auger and air hammer methods through fill, natural soils and rock to a maximum depth of 14m. Groundwater monitoring wells were installed into these boreholes;

Soil sampling from 10 test pits excavated to a maximum depth of 1.5m in the north eastern portion of the Site;

A total of 70 individual soil/fill samples (predominantly fill) collected from depths between 0.0m and 1m were analysed for a combination of Heavy Metals (combination of As, B, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn & Zn), TPH, BTEX, Phenols, Fluoride, Cyanide and Sulphate, OCPs, PCBs, VHC’s and CHCs;

Groundwater sampling was conducted from the two monitoring wells, with samples analysed for Heavy Metals (As, B, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn & Zn), TPH, BTEX, VHCs, CHCs, PAHs, OCPs, PCBs, Total Phenols, Fluoride, Cyanide, Major Ions.

The investigations identified isolated areas of significant TPH, PAH, Arsenic and Lead contamination. Remediation works were undertaken during 2007, comprising excavation of contaminated materials, onsite remediation (landfarming) for selected materials followed by onsite reuse, or offsite disposal of excavated materials. BW undertook supervision of the remediation works and validation sampling/analysis, as summarised below:



67 validation samples were collected from various remedial excavations and analysed for a combination of Arsenic, Mercury, TPH, BTEX and PAH;

15 samples were collected from beneath former sealed roadways and analysed for PAH’s (all samples) and Heavy Metals (As, B, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn & Zn), TPH, BTEX, OCP, PCB, VHC and CHC (3 samples);

33 stockpile samples were analysed for a combination of Heavy Metals (Heavy Metals (combination of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sn & Zn), TPH, MAH, Phenols, Fluoride, Cyanide, PAH, OCP, PCB.

BW concluded that ‘based on the site assessment and remediation works conducted the site in its final condition is considered suitable for sensitive use (residential) land use’.



3. SITE CONDITION AND SURROUNDING ENVIRONMENT

3.1. Site Condition

BW noted the Site conditions to comprise the following during 2006 (pre remediation / demolition works):

The Site was generally flat, with a minor slope to the south;

A number of buildings were located at the Site, as identified below:

Open Machine Shed (south western corner);

Workshop / Office / Storage Building (‘C’ shaped, northern half of central portion);

Incinerator (brick, immediately north east of Workshop / Office / Storage Building);

Fuel / Chemical Storage Building (east of Workshop / Office / Storage Building);

Hoist / Triple Interceptor / Wash Bay Building (southern half of central portion);

Loading Ramp (immediately north of Triple Interceptor);

Spray Painting Shed (east of Hoist / Triple Interceptor Building);

Service Pit / Above Ground Waste Oil Storage Tank (south east of Hoist / Triple Interceptor Building);

Two small sheds (contents not specified) and a Loading Dock (eastern portion);

A Galvanised Iron Shed (contents not specified) was located to the east of Spray Painting Shed.

A concrete loading area was noted adjacent to the eastern boundary of the Site;

Concrete storage bins (containing bluestone screenings) were observed in the north eastern corner of the Site;

Concrete pads and rails were observed in an open storage area located in the south eastern portion of the Site;

Charcoal and ashes were observed in the vicinity of the Incinerator;

Evidence of backfilling was observed adjacent to the north of the Open Machine Shed. BW noted that this area formerly contained UST’s;

Burnt areas where observed in the central and north eastern portions of the Site;

The majority of the surface for the area surrounding the buildings comprised bitumen.

Demolition and remediation works were undertaken during late 2006 / early 2007. A plan showing the pre–demolition / remediation Site layout is presented in Attachment 4, Appendix A.



3.2. Adjacent Uses and Offsite Contamination Sources

3.2.1. Surrounding Property Use The Site was observed by BW to be surrounded by:

Collins Street, further bounded by residential properties, to the north;

Residential properties to the east;

Residential properties to the south;

A vacant property to the west (reportedly formerly part of VicRoads Depot), further bounded by Orion Street.

The industrial property to the west of the Site may pose a historical offsite contamination source. The remaining properties are not considered to pose an offsite contamination source.

3.2.2. Nearby Environmental Audits EPAV Accredited Environmental Auditor (Contaminated Land) Mr. Anthony Lane of Lane Consulting completed an audit for the property located adjacent to the western boundary of the Site (fronting Orion Street) during 2003, the findings of which were presented in Lane Consulting Pty Ltd (May 2003) Environmental Audit Report, 37 Orion Street, Sebastopol, VIC (Ref: 561Report01). Soil and groundwater investigation works as well as soil remediation and validation works have been undertaken at this property.

The soil remediation and validation works were focused on a petroleum storage and distribution area (i.e. UST and associated bowsers) in the eastern portion of the property (adjacent to Site). Identified soil contamination was remediated through excavation and offsite disposal, with remnant soils validated to not contain contamination at unacceptable levels with respect to low density residential use as well as less sensitive and ecological uses.

Groundwater contamination (nitrate) was detected at concentrations exceeding the ANZECC (1992) 95% Protection of Fresh Water Species and ANZECC (1992) Protection of Drinking Water based criteria in groundwater at the Site. Remediation of the identified groundwater contamination was not undertaken and Clean Up to the Extent Practical was assessed to have occurred.

A Statement of Environmental Audit was completed by Mr. Lane which stated that the property was suitable for agricultural, residential (low to high density), recreational/open space and commercial/industrial uses, subject to groundwater at the Site not being extracted for drinking purposes without appropriate groundwater remediation works.

The Auditor does not consider that this property poses a significant offsite contamination source.



3.3. Sensitive Receptors

BW has not identified sensitive receptors. The Auditor has identified the following sensitive receptors:

Future Site users;

Users of surrounding residential properties;

Users and ecosystems of the Yarrowee River, located approximately 200m to the east of the Site. The audit at the front of Orion Street also identified a small tributary of Yarrowee River located to the south of the site, as the nearest receptor.

3.4. Auditor’s Site Inspection

The Site was inspected in three occasions at various stages of the remediation and the key observations are summarised on Table 3.4

Table 3.4 Summary of Auditor Site Inspections

Date Purpose Comments

February 15th 2007 Initial site inspection to assess site conditions prior to remediation.

The site was inspected prior to remediation and the footprints of the main structures at the site were visible.

March 12th 2007 Follow up inspection to assess site following the bulk of remediation.

Verification sample taken.

Remediation of the majority of the site had been undertaken with stockpiles of potentially TPH impacted material, arsenic contaminated material (sands) and asphalt noted on site. There were no visual signs of contamination over the remainder of the site.

A validation sample (V1) was taken of residual silty clay from underneath of the sealed roadways in the centre of the site.

June 11th 2007 Inspection to assess final state of the site following remediation.

All remediation was complete. All stockpiles had been removed and the roads had been formed at the site.

3.5. Auditor’s Conclusion Regarding Site Condition Information

The Auditor considers that the Site condition information provided was adequate and confirms with the auditors observations made during site inspections.



4. SITE HISTORY

4.1. Available Site History Information

CCG provided Site history information based on the following:

A review of historic land title information;

A review of historic aerial photographs;

Review of Dangerous Good Records;

A review of information provided by Pinnacle Property Group;

Discussions with persons using the Site during 2000.

BW also undertook a review of historical aerial photographs.

The available Site history information is summarised below in Table 4.1

Table 4.1 – Site History Summary

Date Activity

1954 - 1994 Site (and adjacent property to west) purchased by VicRoads during 1954. Prior use and ownership not known.

Site (and adjacent property to west) used as VicRoads Regional Plant Branch comprising storage and refuelling of plant/machinery, service/repair of plant/machinery, good storage, bitumen batching and administration uses.

The earliest aerial photograph reviewed indicates that the Site was developed into its pre-demolition layout (i.e. buildings, roads etc.) during 1957 and no significant alterations occurred between 1994 – 2006.

1994 – 2003 Portion of Site and adjacent property to the west leased by AH Plant Hire and used for petroleum storage and distribution as well as plant/machinery repair and maintenance. Remainder of Site leased by E&C Handford (earthworks contractor), Paul Chisolm (Scaffolding) and Smith and Will (road paving and bitumen sealing).

2003 – Present Site vacant and unused, with infrastructure demolished during late 2006.

4.2. Auditor’s Conclusions Regarding Site History Data

The Auditor considers that the Site history information provided was adequate and provides a reasonable basis for the identification of the areas and contaminants of concern at the Site. It is noted that the main site features from the Vic Roads depot were easily identifiable at the start of the investigation.



5. AREAS AND CONTAMINANTS OF CONCERN

5.1. Identified Areas and Contaminants of Concern

CCG/BW identified a number of areas and contaminants of concern at the Site and these have been tabulated in Table 5.1.1.

Table 5.1.1 – Areas and Contaminants of Concern

Area Activity Media Potential Contaminants and Associated Analytes

Former UST Area Storage of petrol/diesel

Soil and groundwater

TPH, BTEX, Lead

Spray Painting Shed Spray painting Soil and groundwater

TPH, Heavy Metals, CHC

Incinerator Incineration of wastes


CHC, TPH and Heavy Metals

Loading Ramp Loading of various chemicals (potentially oils, solvents, fuel)


TPH, BTEX, PAH, Phenol, VHC

Hoist / Triple Interceptor / Wash Bay

Vehicle maintenance and oil waste management



Chemical / Fuel Storage Building

Storage of various chemicals / fuel



Service Pit and Above Ground Waste Storage and Service Pit

Waste oil storage Soil and groundwater


Former Workshop Vehicle maintenance



Roadways, car parks and outside storage areas

Potential use of contaminated sub-base material

Spills of various chemicals


Heavy Metals, TPH, BTEX, PAH, OCP, PCB, Phenol, VHC, CHC

5.2. Auditor’s Conclusion Regarding Identified Areas and Contaminants of Concern

Based on the available Site condition and Site history information, the Auditor considers that BW appropriately identified the areas and contaminants of concern for the Site with the location of most of the above activities obvious at the time of investigation.



6. GEOLOGY AND HYDROGEOLOGY

6.1. Regional Geology

BW noted that based on regional geological information, the local area is underlain by the Quaternary aged Newer Volcanics unit comprising basalt (possibly two distinct units separated by clay, sand and gravel layers) as well as some scoria and tuff, overlain by residual clays soils.

Mr. Lane’s audit report for the property adjacent to the western boundary of the Site also stated that Ordovician aged slate, mudstone and sandstone outcrops to the north and north east of the Site within an incised gully which has been infilled with alluvial and colluvial materials.

6.2. Site Specific Geology

The generalised subsurface conditions at the Site based on borehole logs provided by CCG and BW are summarised in Table 6.2.1.

Table 6.2.1 – Generalised Site Specific Geology

Depth (m)* Subsurface Conditions

0 to <2.4 FILL: Highly variable in depth and composition. silty clay, sand and crushed rock

>0.2 to <2.8 RESIDUAL: Clay, dark grey / brown, medium plasticity, moist.

>0.55 to <12m

WEATHERED BEDROCK: Basalt, grey (with occasional clay seams)

As shown in the table above, the fill depths across the Site are variable. It is noted that the subsurface conditions at the Site have been subject to significant alteration as a result of Site remediation activities (see Section 9).

6.3. Regional Hydrology and Hydrogeology

The closest surface water body is the Yarrowee River, which is located approximately 200m to the east of the Site. However, Mr. Lane’s (2003) audit for the property adjacent to the western boundary of the Site indicates groundwater most likely flows to the south west, following the dip of the basalt unit.

Based on the findings of the investigation works undertaken on the property adjacent to the western boundary of the Site, groundwater was expected to occur beneath the Site within the upper portions of the basalt. Standing water levels would be expected to occur around approximately 8m below ground surface.

BW did not undertake a registered bore search with relation to the Site and nearby properties. Mr. Lane’s (2003) audit report noted that a registered bore search was undertaken in association with the investigation of the property to the west of the Site, which identified the following:

24 bores were identified within a 2km radius;

The nearest registered bore was located 400m to the south west;



The only bore with data provided (located 1.8km to the south west) was screened across basalt from 20m to 55m, with the groundwater having a pH of 6.9, EC of 230us/cm and TDS of 150mg/L;

No comments regarding the registered use of the bores were provided.

6.4. Site Specific Hydrogeology

Groundwater investigations were undertaken at the Site by BW during 2006, through which the Site specific hydrogeological data presented in Table 6.4.1 has been obtained.

Table 6.4.1 – Site Specific Hydrogeology

Aspect Details

Aquifers Identified One, within upper portions of basalt.

Geology Investigated Fill, Residual Clays and upper portions of basalt (wells screened within Basalt from 5m to 14m and 5m to 13m)

Depth to Water Approximately 9mBTOC to 10mBTOC (potentiometric)

Phase Separated Hydrocarbon None identified.

Hydraulic Gradient Not assessed.

Hydraulic Conductivity Not assessed.

Effective Porosity Not assessed.

Seepage Velocity Not assessed.

Interpreted Flow Direction South west (based on data from Mr. Lane’s 2003 audit for the property immediately west of the Site)

Groundwater Quality (approximates) TDS – <1,000mg/L, pH – 7, Redox –20mv to 80mv, Temperature – 140C

NOTES: BTOC – Below Top Of Casing, m/d – metres per day

It is noted that BW obtained approval to construct groundwater investigation bores at the Site from Southern Rural Water.

6.5. Auditors Conclusion Regarding Geology and Hydrogeology Data

The Auditor considers that the geology and hydrogeology information provided was adequate.



7. EVALUATION OF QUALITY ASSURANCE AND QUALITY CONTROL

7.1. Review of Consultants Data

The Auditor has assessed the adequacy of the sampling and analysis methodology and field and laboratory quality assurance/quality control measures for the works subject to the Audit. The Auditor has made this assessment with respect to the relevant requirements presented in the following documents:

Australian Standard AS 4482.1 (2005) Guide to the sampling and investigation of potentially contaminated soil. Part 1: Non-volatile and semi-volatile compounds;

Australian Standard AS 4482.2 (1999) Guide to the sampling and investigation of potentially contaminated soil. Part 2: Volatile Substances;

Australian Standard AS 5667.6 (1998) Water quality - Sampling - Guidance on sampling of groundwaters;

Australian Standard AS 5667.11 (1998) Water quality - Sampling - Guidance on sampling of rivers and streams;

EPAV (March 2000, Publication 441) A Guide to the Sampling and Analysis of Waters, Wastewaters, Soils and Wastes;

EPAV (April 2000, Publication 669) Groundwater Sampling Guidelines;

EPAV (March 2000, Publication 441) A Guide to the Sampling and Analysis of Waters, Wastewaters, Soils and Wastes;

EPAV (Sept 2006, Publication 668) Environmental Auditing, Hydrogeological Assessment (Groundwater Quality) Guidelines;

Land and Water Biodiversity Committee (2003) Minimum Construction Requirements for Water Bores in Australia (Edition 2, Revised September 2003);

National Environment Protection Council (1999) National Environment Protection (Assessment of Site Contamination) Measure.

The Auditor has not assessed the suitability of the assessment works undertaken by CCG or relied on the data from these investigations for the following reasons:

The works undertaken by CCG included extensive composite sampling and analysis for non-volatile, semi-volatile and volatile compounds. Composite sampling is only useful as a screening tool and is not suitable for semi-volatile and volatile compounds; and

The works undertaken by BW have included an assessment of the areas previously assessed by CCG.

The data from the CCG investigations has been considered for comparison purposes when assessing the BW investigation data.



7.2. Investigation Adequacy

7.2.1. Review of Sampling and Analysis Methodology The Auditors assessment regarding the adequacy of the sampling and analysis methodology implemented during the investigation/validation works subject to the Audit (described in detail in Section 2) is presented below:

Soil investigations:

The soil investigation locations are considered to have been adequate to target the specific areas and concern as well as provide general Site coverage. The soil investigation locations are considered to have been appropriate;

The soil investigations were generally extended to refusal on bedrock and these investigation depths are considered to have been adequate;

The sample analysis is considered to have adequately taken into account the contaminants of concern and an adequate number of samples are considered to have been analysed. It is noted that the sample analysis in a number of areas where a range of volatile contaminants may have been used did not include VHC analysis, however, TPH C6-C9 analysis is considered to be adequate to indicate whether a range of volatile contaminants may have been present.

Groundwater investigations:

Two monitoring wells were installed and constructed to target basalt and sandy/clay from 5m to <14m, including one in the south eastern corner and one in the north eastern corner. It is noted that a well identified as GW3 was installed at the Site during investigations undertaken on the adjacent portion of 37 Orion Street by Diomides & Associates during 2003. As two rounds of monitoring data were available for this well, BW did not consider it necessary to sample this well. The Auditor considers that this is reasonable;

Groundwater samples collected from the wells are considered to have been analysed for an appropriate analytical suite;

It is noted that the monitoring wells were decommissioned during the remediation works, with the top of each well excavated to 1m and grout poured into the well and excavation.

Soil validation:

Validation samples (see Table 9.3.2.1 for detailed summary) were collected and analysed from the remedial excavation bases at a rate of approximately 1 sample per <50m2 for relatively small excavations and between 100m2 and 1,300m2 for relatively large excavations (i.e. Workshop / Office / Storage / Incinerator Building & Sealed Roadways). The base sampling is considered to have been appropriate given that the contamination (where present) was visually apparent ;

Validation samples (see Table 9.3.2.1 for detailed summary) were collected and analysed from each wall of the Chemical / Fuel Building, Hoist / Triple Interceptor / Wash Bay, and Service Pit excavations at a rate of approximately <20m2. This validation sampling is considered to have been adequate;

Validation samples were not collected from the walls of the following excavations. Note that that the contamination (where present) was visually apparent which aided in the identification of the extent of the excavations:



- North Eastern Corner – No wall sampling was required as the excavation was shallow (<0.2m) and contamination had been well delineated by BW sampling locations TP06-1 to TP06-4;

- Loading Ramp – 2 wall samples were collected from the western end of the excavation, however, no other wall samples were collected. No wall samples were collected from the eastern end as this area formed a ramp which was higher in elevation prior to excavation and following excavation was only about 0.1m below the ground surface.

- Workshop / Office / Storage / Incinerator Building – No wall samples were collected, however, the excavation was shallow (<0.3m) and near surface soil sampling undertaken by BW following the removal of the sealed roadways and underlying sub-base indicates that the extents of the excavation were most likely appropriate;

- Above Ground Waste Storage Tank – No wall samples were collected, however, the excavation was shallow (<0.3m) and near surface soil sampling undertaken during the investigation phase, validation of the adjacent Service Pit excavation and following the removal of the sealed roadways and underlying sub-base indicates that the extents of the excavation were most likely appropriate;

- Sealed Roadways – No wall sampling was required and the excavations comprised a shallow surface strip across the sealed areas of the Site.

Stockpile samples were collected and analysed at a rate of approximately 1 per 25m3 for material reused onsite and a greater rate (50m3 to 80m3) for material disposed of offsite. The stockpile sampling rates are considered to have been generally adequate;

The validation and stockpile samples were analysed for the specific contaminants of concern identified during the soil investigations (see Table 9.3.2.1). The validation sample analysis is considered to have been adequate.

7.3. Data Usability

The Auditors assessment regarding the field and laboratory quality assurance and quality control measures and results during the works subject to the Audit is presented in Appendix E and summarised below:

The field and laboratory quality assurance measures implemented are considered to provide a reasonable level of confidence that the data is likely to be appropriately complete, comparable and representative;

The field and laboratory quality control measures implemented are considered to provide a reasonable level of confidence that the data is likely to be appropriately accurate and precise.

Based on the above, the data for the works subject to the Audit is considered to most likely be reliable and usable for the purposes of the Audit. It is noted that PQL’s in groundwater for some contaminants (selected PAH, PCB, OCP, VHC and CHC analytes) were above assessment criteria, this has been taken into account when interpreting the data.



8. ENVIRONMENTAL QUALITY CRITERIA

8.1. General

The applicable Environmental Quality Criteria are discussed below.

8.2. Soil

8.2.1. Protection of Human Health The Auditor has assessed the significance of selected heavy metals, PAHs, OCPs, OPPs, PCBs and Phenol concentrations in soil with reference to protection of human health based investigation levels (HILs) presented in Schedule B(1) of National Environment Protection Council (1999) National Environment Protection (Assessment of Site Contamination) Measure. These guidelines contain different threshold concentrations for various land use settings (HIL A to F) and all of these guidelines have been used to assess the impact of contaminant levels on Human Heath beneficial use.

‘residential with gardens and accessible soils’ use (HIL A)

‘Residential with minimal opportunities for soil access’ (HIL D).

‘parks/recreational/open space’ use (HIL E)

‘commercial/industrial’ use (HIL F).

Based on the proposed land use being low density residential, the applicable land use setting is considered to be ‘residential with gardens and accessible soils’ use (HIL A). It is important to note that NEPM (1999) states these guidelines are to be used as a screening criteria only, however, in practice they are widely used as acceptance criteria / clean-up criteria.

NSW EPA (1994) Guidelines for Assessing Service Station Sites have also been referred to for assessing TPH and BTEX results.

8.2.2. Protection of the Environment The provisional phytotoxicity based environmental investigation levels (EILs) presented in NEPC (1999) have been used to assess potential for detrimental impacts to the environment as a result of selected Heavy Metal concentrations in soil. It is important to note that the scientific basis for the NEPM (1999) EIL’s is poor and NEPM (1999), Schedule B(1), Section 3.2 states that ‘… the EILs for an urban setting have not been derived to protect nominated ecological values and are somewhat arbitrary’. As such, the Auditor has used the EIL’s as screening criteria and relied upon a qualitative assessment of the contaminant distribution and background conditions when assessing the significance of EIL exceedances. It is also pertinent to note that phytotoxicity is primarily associated with the fraction of Heavy Metals which are sorbed to soil particles or bound within a rock matrix which are soluble in water and as such may be taken up by plants. As such, the comparison of total Heavy Metals results in soil against the EIL’s in order to assess phytotoxicity has some limitations.

The protection of terrestrial organisms based guidelines presented in NSW EPA (1994) have been used to assess potential detrimental impacts to the environment as a result of Toluene, Ethylbenzene and Xylene concentrations in soil.

8.2.3. Buildings and Structures Australian Standard AS 2159 (1995) Piling – Design and Installation provides exposure classification values for concrete and steel piles in soil (non-aggressive to very severely aggressive). In the absence of a directly applicable EPA endorsed criteria, these guidelines are



considered to be appropriate in assessing the potential for detrimental impacts of Site soils to buildings and structures.

In addition to the above, the presence of other aggressive chemical compounds (e.g. acids) may be potentially detrimental to buildings or structures.

8.2.4. Aesthetics The Auditor has considered the need for remediation based on the ‘aesthetic’ contamination as outlined in Schedule B(1) of the NEPM (1999) that states that ‘there are no numeric Aesthetic Guidelines but the fundamental principle is that the soils should not be discoloured, malodorous (including when dug over or wet) nor of abnormal consistency. The natural state of the soil should be considered’.

8.2.5. Production of Food, Flora and Fibre SEPP (Prevention and Management of Contamination of Land) states that ‘Contamination of land must not……..(b) affect the level of any indicator in food, flora and fibre produced at the site (or that may be produced) such that the level of that indicator is greater than that specified by the Australia New Zealand Food Authority, Food Standards Code.’

The Food Standards Code provides Maximum Levels (MLs) for various organic and inorganic chemicals in various foods, with the MLs for each chemical varying dependant on the food type. The Food Standards Code does not provide threshold criteria for contaminant levels in soils. The correlation between contaminant levels in soils and resulting contaminant levels in food, flora and fibre produced in soils is complex and related to the bioavailability of the contaminant, the rate at which the contaminant is taken up by the crop / stock and the ability of various crop / stock to regulate the contaminant.

As a conservative measure and in the absence of directly applicable criteria, the Auditor has assessed that the Site has been contaminated at unacceptable levels with respect to the production of food, flora and fibre if the contaminants of concern are present at levels above that which can reasonably be considered to represent natural background levels.

8.3. Groundwater

SEPP (Groundwaters of Victoria) provides guidance on groundwater criteria, primarily based on the Australian and New Zealand Environment and Conservation Council (ANZECC) / National Health and Medical Research Council (NHMRC) (1992) Australian and New Zealand Guidelines for the Assessment and Management of Contaminated Sites (hereafter referred to as ANZECC 1992). ANZECC 1992 was rescinded by the NHMRC on 14 March 2002 and is to be used for historical purposes only. The following documents are currently endorsed under the National Water Quality Management Strategy and of relevance to the assessment of groundwater quality as part of the Audit:

Australian and New Zealand Environment and Conservation Council (ANZECC) / Agricultural and Resource Management Council of Australia and New Zealand (ARMCANZ) (2000) Australian and New Zealand Guidelines for Fresh and Marine Water Quality (hereafter referred to as ANZECC 2000);

National Health and Medical Research Council (NHMRC) / National Resource Management Ministerial Council (NRMMC) (2004) Australia Drinking Water Guidelines (hereafter referred to as NHMRC/NRMMC 20004).

8.3.1. Protection of Ecosystems The Auditor has assessed the groundwater data with reference to ANZECC (2000). Trigger values (TVs) provided are concentrations that, if exceeded, indicate a potential environmental



problem and ‘trigger’ further investigation. It is noted that these guidelines apply to the protection of species in surface water systems and it is considered to be conservative to apply the guidelines to groundwater systems.

The nearest surface water receptor is Yarrowee River located approximately 200m to the east of the Site. This surface water body is understood to be a fresh water system and as such the Auditor has applied the ANZECC (2000) criteria for fresh water species.

Low reliability ANZECC (2000) TVs have been used where they exist for the individual PAHs. However, a trigger level for total PAHs within groundwater is not provided within the ANZECC (2000) guidelines. As such, the threshold level of 3µg/L from the EPA (1994) Guidelines for Assessing Service Station Sites has been adopted.

There are no reliable Australian criteria for TPH in groundwater, therefore, reference has been made to the Netherlands Intervention Value of 600µg/L for Mineral Oil (1999) for the assessment of TPH C10-C36 in groundwater.

8.3.2. Protection of Human Health – Potable Drinking Water The NHMRC / NRMMC (2004) Australian Drinking Water Guidelines have been used to assess potential detrimental effects of groundwater contamination to human health when ingested.

Where available, the US EPA (2004) Region IX Preliminary Remediation Goals, conservative risk based values for tap water, were also referred to. The approach taken in the assessment of certain chemicals is significantly different to that taken in Australia. This must be taken into account when referring to these guidelines.

8.3.3. Protection of Human Health – Potable Mineral Water SEPP (Groundwaters of Victoria) refers to potable mineral water criteria referred to in ANZECC 1992. As ANZECC 1992 has been rescinded and the Auditor is not aware of any more recent mineral water specific criteria, the Auditor has assessed potable mineral water as per ANZECC (2000) potable drinking water guidelines.

8.3.4. Protection of Human Health – Agriculture, Parks and Gardens

Section 9.2 of ANZECC (2000) presents guidelines for irrigation water. The Auditor has used these guidelines, noting that the number of chemicals which guidance is provided for is very limited.

8.3.5. Protection of Livestock Section 9.3 of ANZECC (2000) presents guidelines for livestock water. The Auditor has used these guidelines, noting that the number of chemicals which guidance is provided for is very limited.

8.3.6. Industrial Water Use ANZECC (2000) provides guidance for general water use based on pH and the associated corrosion potential (high potential pH <5) or fouling potential (low potential pH <7). In addition, ANZECC (1992), provides guidance on industrial use based on TDS, as summarised below:

Make-up water systems for fresh water – <500mg/L;

Textiles – <100mg/L;

Pulp and paper industry – < 500mg/L;



Petroleum industry – <750mg/L.

8.3.7. Protection of Human Health – Primary Contact Recreation The guidelines for recreational purposes presented in Table 5.2.3 of ANZECC (2000) have been used to assess potential detrimental effects of groundwater contamination to human users of surface waters where Site originated groundwater is expected to discharge.

8.3.8. Buildings and Structures Australian Standard AS 2159 (1995) Piling – Design and Installation provides exposure classification values for concrete and steel piles in soil (non-aggressive to very severely aggressive). In the absence of a directly applicable EPAV endorsed criteria, these guidelines are considered to be appropriate in assessing the potential for impacts on buildings and structures. In addition, the presence of other aggressive chemical compounds (e.g. acids) may be potentially detrimental to buildings or structures.

8.4. Criteria Used by BW

BW did not assess soil and groundwater results against all beneficial uses which the Auditor considers relevant (see Section 9) and as such all relevant criteria were not identified. However, where applied, the criteria applied by BW were appropriate.



9. EVALUATION OF SOIL ANALYTICAL RESULTS & SOIL REMEDIATION WORKS

9.1. Summary of Soil Investigation Results (CCG 2000)

The following presents a summary of the CCG soil analytical results, which have been used for comparative purposes only:

Heavy Metals were detected at concentrations below the EQC for low density residential use and generally below the lower of the NEPM (1999) HIL A or EIL criteria, with the exception of a combination of Arsenic, Copper, Total Chromium, Nickel and Zinc at a number of locations;

OCP, PCB, VHC, CHC and Total Phenolics were not detected above laboratory PQLs and as such are unlikely to be present at concentrations exceeding the laboratory PQLs, noting that the analysis of composite samples is not suitable for the majority of these compounds;

A number of TPH fractions and BTEX / PAH compounds were detected at low concentrations marginally exceeding the PQLs (below EQC for low density residential) in a number of composite samples. As sample compositing is not an appropriate method for volatile (i.e. BTEX, TPH C6-C9) and semi-volatile (i.e. PAHs and TPH C10-C36) compounds, these results are considered to be indicative of potential TPH, BTEX and PAH contamination requiring appropriate assessment.

9.2. Summary of Soil Investigation Results (BW 2006)

Laboratory result summary tables prepared by BW have been reproduced in Attachment 4, Appendix A. The following presents a summary of the BW (2006) soil investigation results:

TPH C6-C9 was detected at concentrations exceeding the protection of human health based EQC of 65mg/kg in the vicinity of:

The former Chemical/Fuel Storage Building (sample BH06-26 0.15-0.25: C6-C9 – 65mg/kg, and BH06-26 0.4-0.5: C6-C9 – 90mg/kg).

Location BH06-26 was beneath the approximate centre of the former Chemical/Fuel Storage Building. The vertical extent of the TPH C6-C9 contamination was not identified.

TPH C10-C36 was detected at concentrations exceeding the HIL A criteria of 1,000mg/kg in the vicinity of:

The former Loading Ramp (sample BH06-10 0.0-0.1: C10-C36 – 3,228mg/kg);

The north eastern corner (sample BH06-GW2 0.4-0.5: C10-C36 – 1,400mg /kg);

The former Triple Interceptor (sample BH06-24 0.15-0.25: C10-C36 – 1,490mg /kg);

The former Above Ground Waste Oil Storage Area (sample BH06-18 0.0-0.1: C10-C36 – 3,100mg /kg);

The former Chemical / Fuel Storage Building (samples BH06-26 0.15-0.25: C10-C36 – 1,100mg /kg, TP06-5 0.9-1.0: C10-C36 – 3,220mg /kg, and TP06-6 0.3-0.4: C10-C36 – 3,800mg /kg).



Benzo(a)pyrene (B(a)P) and/or Total PAH’s were detected at concentrations exceeding the HIL A criteria of 1mg/kg and 20mg/kg, respectively, in the vicinity of:

The north eastern portion of the Site (BH06-4 0.0-0.1: B(a)P – 2.1mg/kg, Total PAH – 21mg/kg);

The eastern portion of the Site, to the west of the concrete loading area (BH06-5 0.0-0.1: B(a)P – 1.3mg/kg);

The south western portion of the Site (BH06-8 0.0-0.1: B(a)P – 1.6mg/kg, Total PAH – 33mg/kg, and BH06-12 0.0-0.1: B(a)P – 3.8mg/kg, Total PAH – 42mg/kg);

The former Triple Interceptor (BH06-24 0.15-0.25: B(a)P – 5.2mg/kg, Total PAH – 67mg/kg);

The former Above Ground Waste Oil Storage Area (BH06-18 0.0-0.1: B(a)P – 4.3mg/kg and Total PAH – 54mg/kg).

To the north of the former Chemical / Fuel Storage Building (TP06-10 0-0.1: B(a)P – 2.4mg/kg).

The vertical extent of the PAH contamination was not defined at any location apart from BH06-24, where B(a)P and PAH’s were <PQL’s at a depth of 0.25m-0.35m. It is considered that the PAH contamination was most likely associated with contaminated fill material as opposed to contamination from historical onsite activities.

Arsenic was detected at concentrations exceeding the HIL A criteria of 100mg/kg in the vicinity of:

The former Hoist (sample BH6-20 0.4-0.5: As – 450mg/kg);

The former Workshop (samples BH06-23 0.15-0.25: As – 270mg/kg, and BH06-27 0.15-0.2: As – 200mg/kg); and

The former Office (sample BH06-31 0.13-0.2: As – 180mg/kg).

The Arsenic contamination appeared to have been primarily associated with packing sand fill material.

Lead was detected at concentrations exceeding the HIL A criteria of 300mg/kg:

In the south eastern portion of the Site (sample BH06-GW1 0.4-0.5: Pb – 610mg/kg).

Numerous exceedances of the protection of the environment based EQC (i.e. NEPM EIL’s) were detected across the Site for Arsenic (16), Barium (2), Manganese (6), Mercury (1), Nickel (9), Lead (1) and Zinc (2);

The remaining contaminants of concern were detected at concentrations below the EQC or were not detected above PQL’s.




9.3. Soil Remediation Works

9.3.1. Soil Remediation Approach BW provided a ‘Procedure for Remediation Works’ (dated 21/11/06) which detailed the proposed remediation approach for the Site. The document provided identified that based on soil analytical results from the invasive investigations; remediation works were required in the following areas:

Loading Ramp;

Hoist/triple interceptor trap building;

Chemical/Fuel Storage Building;

Workshop and Office Buildings;

Service Pit and Above Ground Waste Oil Storage Area;

Sealed roadways, car parks and outside storage areas.

BW proposed that the remediation works be undertaken through the excavation of unsuitable soils (nominal excavation depths stated for each area), waste classification and offsite disposal of the excavated materials (anticipated volumes stated) and validation of the remnant soils through sampling/analysis.

The Procedure for Remediation Works did not provide an assessment of possible remediation options or a justification for the selected remedial approach. However, the Auditor considers that the remediation approach was suitable.

9.3.2. Assessment of Remediation and Validation Activities The following table presents a summary of the remediation works undertaken at the Site between 28 November 2006 and 8 March 2007. A figure showing the location and lateral extent of the respective remediation areas is presented in Attachment 4, Appendix A.


Table 9.3.2.1 Summary of Remediation and Validation Works (28/11/06 to 8/3/07)

Area Excavation Dimensions (m)

Excavated soil volume (m3)

Excavation Base and wall sampling rates

Summary of Excavation Validation sampling results

Remediation / Stockpile sampling

Summary of Stockpile Sampling Results / Excavated Soil Fate

North Eastern Corner

Lateral – 3.7m by 3.4m

Depth – <0.2m

2.5m3 1 base sample (1 per 12.5m2) analysed for TPH.

TPH < SIL’s Stockpile periodically turned an unspecified number of times (due to presence of odorous soils) between November 2006 / January 2007.

1 sample (1 per 2.5m3) collected post-remediation and analysed for TPH.

TPH < SIL’s / Material reused onsite.

Chemical / Fuel Building

Lateral – 13m by 13m

Depth – 0.8m to 1.7m

150 m3 of Clay

4 base samples (approx. 1 per 40m2) & 9 wall samples (approx. 1 per 10m2) analysed for TPH / BTEX (13) and PAH (8)

TPH / BTEX <SIL’s and PAH’s < HIL A.

Stockpile periodically turned an unspecified number of times (due to presence of odorous soils) between November 2006 / January 2007.

2 stockpile samples collected pre- remediation and analysed for Heavy Metals (13), TPH, MAH, PAH, PCB, OCP, Phenols, Fluoride and Cyanide.

4 stockpile samples collected post-remediation and analysed for TPH.

TPH / BTEX < SIL’s, PAH, PCB, OCP and Phenols < HIL A and soils not odorous following remediation/ Material reused onsite.

Hoist / Triple Interceptor / Wash Bay

Lateral – 18m by 12.5m


150m3 of Clay

50m3 of packing sands

8 base samples (approx. 1 per 28m2) and 8 wall samples (approx. 1 per 20m2) analysed for TPH (16),


Clay and packing sands separated into two separation stockpiles.

1 sample collected from packing sands and analysed

Heavy Metals (13), TPH, MAH< PAH, PCB, OCP, Phenols, Fluoride and Cyanide with the exception of Arsenic >HIL A criteria of 100mg/kg in packing sands / Packing sand disposed of to A & B










BTEX (7) and PAH (10).

for Heavy Metals (13), TPH, MAH< PAH, PCB, OCP, Phenols, Fluoride and Cyanide.

Clay stockpile periodically turned an unspecified number of times (due to presence of odorous soils) between November 2006 / January 2007.

1 sample collected from clay stockpile pre-remediation and analysed for Heavy Metals (13), TPH, MAH, PAH, PCB, OCP, Phenols, Fluoride and Cyanide.

4 stockpile samples collected post remediation and analysed for TPH.

Mihaljevic’s property located at 73-81 Hertford Street in accordance with a EPAV Notice of Approval for Supply of a Notifiable Chemical and Confirmation of Receipt of Notifiable Chemical (dated 6 March 2007), see Appendix F

TPH < PQL’s and soils not odorous in clay stockpile following remediation/ Material reused onsite.

Workshop / Office / Storage / Incinerator Building



400m3 of packing sands

16 base samples (approx. 1 per 135m2) and analysed for Arsenic and Mercury.

Arsenic and Mercury <HIL A and <EIL, apart from Arsenic >EIL of 20mg/kg but < HIL A of 100mg/kg in 6 samples (34mg/kg to 81mg/kg).

2 samples analysed for Arsenic / Mercury and 3 samples analysed for Heavy Metals (13), TPH, MAH, PAH, PCB, OCP, Phenols, Fluoride and Cyanide.

Heavy Metals (13), TPH, MAH< PAH, PCB, OCP, Phenols, Fluoride and Cyanide , with exception of Arsenic > HIL A criteria of 100mg/kg in 5 samples (120mg/kg to 1,200mg/kg).

Packing sand disposed of to A & B Mihaljevic’s property located at 73-81 Hertford Street in accordance with a EPAV Notice of Approval for Supply of a Notifiable Chemical and Confirmation of Receipt of










Notifiable Chemical (dated 6 March 2007).

Loading Ramp Lateral – 35m by 13m

Depth – <1.3m

350m3 10 base samples (approx. 1 per 45m2) & 2 wall samples analysed for TPH / PAH (12) and BTEX (4). It is noted that the three wall samples were all collected from the western end of the excavation


Stockpile periodically turned an unspecified number of times (due to presence of significant hydrocarbon concentrations and odorous soils) between December 2006 / January 2007.

Seven samples collected pre-remediation, with 3 analysed for Heavy Metals (13), TPH, MAH, PAH, PCB, OCP, Phenols, Fluoride and Cyanide, and four analysed for TPH only.

6 samples collected post remediation and analysed for TPH

Heavy Metals (13), MAH, PAH, PCB, OCP, Phenols, Fluoride and Cyanide < HIL A criteria. TPH C10-C36 > SIL of 1,000mg/kg in 3 pre-remediation samples. TPH C10- C36 < SIL of 1,000mg/kg in post remediation samples. Soil not odorous following remediation. / Material reused onsite.

Service Pit and Above Ground Waste Storage Tank

Service Pit


Depth – <1.7m

1 base sample ( per 28m2) and 6 wall samples (approx. 1 per 6m2) analysed for TPH and PAH.

TPH <SIL’s and PAH’s < HIL A.

Above Ground Waste Storage Tank

Lateral – 8m

50m3

3 base samples (approx. 1 per 10m2) analysed for TPH and PAH.

TPH <SIL’s and PAH’s < HIL A.

Stockpile periodically turned an unspecified number of times (due to presence of significant hydrocarbon concentrations and odorous soils) between December 2006 / January 2007.

1 sample collected pre-remediation and analysed for Heavy Metals (13), TPH, MAH, PAH, PCB, OCP, Phenols, Fluoride and

Heavy Metals (13), TPH, MAH< PAH, PCB, OCP, Phenols, Fluoride and Cyanide < HIL A or SIL criteria (as applicable). Soil not odorous following remediation. / Material reused onsite.











by 4m

Depth – <0.4m

Cyanide.

1 sample collected post-remediation and analysed for TPH.

Sealed Roadways


Depth – <0.4m

1,500m3

15 base samples (1 sample per 1,300m2) and analysed for PAH’s (all samples) and Heavy Metals (As, B, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn & Zn), TPH, BTEX, OCP, PCB, VHC and CHC (3).

PAH’s, Heavy Metals, TPH, BTEX, OCP, PCB, VHC and CHC < HIL A / SIL and EIL (where applicable), with the exception of:

- Arsenic > EIL of 20mg/kg in 1 sample (33mg/kg);

- Nickel > EIL of 60mg/kg in 1 sample (70mg/kg).

NA

A letter signed by the Client’s Representative has been provided indicating the following:

The majority of asphalt driveways were removed and transported to ‘Chris Bev Waste’ at Redan/Ballarat (estimated volume not clear).

Approximately 15 ‘truck loads’ of asphalt and blue steel sub-base were disposed of to ‘an industrial allotment in Bala Street, Sebastopol.

Approximately 30 ‘truck loads’ of asphalt and blue steel sub-base were disposed of to 73-71 Hertford Street, Sebastopol.


9.4. Auditor’s Verification Sampling Results

The Auditor collected a verification sample identified as V1 on 9th March 2007 the centre of the site following removal of the Sealed Roadways. The sample was analysed for Sulphate, Chloride, Heavy Metals (As, Cr, CrVI, Cd, Cu, Pb, Ni, Zn, Hg), TPH, BTEX and PAH.

The Auditor’s verification sampling supported the findings of the BW investigations / validation, with TPH, BTEX and PAH not detected above PQL’s and Heavy Metals detected at low levels below NEPM (1999) HIL A / EIL criteria

9.5. Summary of Remnant Soils

The following presents a summary of the key contaminants of concern (i.e. contaminants which were detected above screening criteria during investigations and/or validation sampling) in soil remaining at the site:

Table 9.5.1 Summary of Key Contaminants of Concern in Remnant Soils

Analyte n n > PQL

SIL or HIL A Criteria

n > SIL or HIL A (as applicable)

EIL Criteria

n > EIL

Mean (mg/kg)

Standard Deviation (mg/kg)

Arsenic 39 22 100 0 20 10 17 20

Barium 19 19 - 0 300 1 100 156

Mercury 39 11 15 0 1 0 0.08 0.068

Manganese 18 17 1500 0 500 4 311 239

Lead 19 12 300 1 600 1 50 137

Nickel 19 14 600 0 60 6 45 41

Zinc 19 15 7,000 0 200 1 54 59

TPH C10-C36 65 33 1,000 0 - - 220 195

Benzo(a)pyrene 44 11 1 0 - - 0.13 0.1

Total PAH 44 18 20 0 - - 1.8 1

- = no criteria

Table 9.5.1 indicates that with the exception of Lead in 1 sample, the key contaminants of concern are not present in remnant soils at concentrations exceeding HIL A / SIL criteria. The Lead exceedance represents sample BH06-GW10.4m-0.5m, where Lead was detected at a concentration of 610mg/kg and no remediation works were subsequently undertaken. In accordance with the NEPM (1999), as the exceedance is less than 2.5 times the screening criteria of 300mg/kg and the standard deviation of Lead concentrations in remnant soils is less than 50% of the screening criteria, the isolated pocket of elevated Lead is not considered to be significant.

Table 9.5.1 also indicates that the Arsenic, Barium, Manganese, Lead, Nickel and Zinc exceeded EIL’s in some samples.



The following sections presents an assessment of the relevant beneficial uses which may be made of the Site (Section 9.6) and the significance of the remnant soil impacts with respect to the objectives of the relevant beneficial uses (Section 9.7).

9.6. Beneficial Uses Assessment - Soils

SEPP (Prevention and Management of Contamination of Land) details beneficial land uses to be protected dependant on the land use, as presented in the table below.

Table 9.6.1 Beneficial Uses to be protected based on land use (after table 1, SEPP Prevention and Management of Contamination of Land).

As previously stated, the proposed residential development at the Site comprises subdivision for 41 residential lots with an average size of 556m2. It is anticipated that each lot will contain a single residential dwelling.

Appendix 4 of EPAV publication 759b provides definitions and generic descriptions of various residential land use descriptions. Based on the above density and access to soil the proposed development falls into the single dwelling residential category.

Based on the above category of residential use, Table 1 of SEPP (Prevention and Management of Contamination of Land) recommends that the following beneficial uses should be protected:

Ecosystem maintenance (modified ecosystems);

Ecosystem maintenance (highly modified ecosystems);

Human health;

Buildings and structures;



Aesthetics;

Production of food, flora and fibre.

Indicators used to determine whether the above objectives are met are generally levels of chemical substances relative to the assessment criteria specified in the NEPM (1999), or other applicable EPAV endorsed guidelines. The table below, which is based on Table 2 from SEPP (Prevention and Management of Contamination of Land), summarises the indicators and objectives for the relevant beneficial use.

Table 9.6.2 – Indicators and Objectives for Beneficial Land Uses (modified from SEPP 2002)

Beneficial Land Use Indicators Objectives

Level of indicator must not be greater than the ecological investigation level (EIL), other appropriately derived risk based criteria or levels approved by the EPA.

Maintenance of ecosystems

Chemical substances or waste identified in NEPM Schedule B (2) Appendix 1

Level of indicator chemical must not be greater than the health risk-based threshold levels (HIL A to HIL F) for specified land uses i.e. HIL D for this site or other appropriately derived risk based criteria or levels approved by the EPA.

Protection of human health

Chemical substances or waste identified in NEPM Schedule B (2) Appendix 1

Buildings & Structures

pH, sulfate, Redox potential, salinity or any potentially detrimental chemical substance or waste

Contamination must not cause the land to be corrosive to or adversely affect the integrity of structures or building materials.

Aesthetics Offensive substances – visual or olfactory

Contamination not to cause the land to be offensive to the senses of human beings.

Contamination of land must not: (a) adversely affect produce quality or yield; and (b) affect the level of any indicator in food, flora and fibre produced at the site (or that may be produced) such that the level of that indicator is greater than that specified by the Australia New Zealand Food Authority, Food Standards Code.

Chemical substances or waste identified through the application of the National Environment Protection

Production of food and flora and fibre (Assessment of Site

Contamination) Measure (Schedule B(2), Appendix 1)

9.7. Implication of Remnant Soil Analytical Results – Impact to

Beneficial Uses

9.7.1. Ecosystem maintenance A number of samples representing remnant soils have detected a combination of Arsenic, Barium, Manganese, Lead, Nickel and Zinc at levels exceeding the NEPM (1999) EIL’s, as summarised in the table below:

or any other chemical substance or waste.



Table 9.7.1.1 Summary of EIL Exceedances (Remnant Soils)

Analyte EIL (mg/kg)

Samples > EIL

Sample Depth (m) / Material

Concentration (mg/kg)

Mean (mg/kg)

06-GW2-2 0.4 – 0.5 / Clay 21

06-9-1 0.0-0.1 / Sand Fill 29

06-19-2 0.9 – 1.0 / Clay 28

1112-V29 0.2 / Clay 67

1112-V33 0.2 / Clay 34

1112-V37 0.2 / Clay 81

1112-V38 0.2 / Clay 63

1112-V40 0.2 / Clay 57

1112-V41 0.2 / Clay 42

Arsenic 20

1502-V79 0.0 / Sand Fill 33

17

Barium 300 06-4-2 0.4 – 0.5 / Clay 690 100

06-4-2 0.4 – 0.5 / Clay 690

06-14-2 0.4 – 0.5 / Crushed Rock 570

06-16-2 0.4 – 0.5 / Crushed Rock 570 Managanese 500

06-19-1 0.3 – 0.4 / Crushed Rock 590

311

Lead 600 06-GW1-2 0.4 – 0.5 / Clay 610 50

06-4-2 0.4 – 0.5 / Clay 130

06-14-1 0.0 – 0.1 / Crushed Rock 73

06-14-2 0.4 – 0.5 /Crushed Rock 74

06-16-2 0.4 – 0.5 / Crushed Rock 130

06-19-1 0.3 – 0.4 / Crushed Rock 98

Nickel 60

1502-V83 0.0 / Crushed Rock 70

45

Zinc 200 06-GW1-2 0.4-0.5 / Clay 230 54

The following presents a discussion of the significance of the data presented in Table 9.7.1.1:

Arsenic: The elevated Arsenic concentrations were associated with residual clays (8 samples) or sand fill (2 samples). The exceedances were relatively minor and there is no evident pattern of contamination indicative of a source of Arsenic contamination. It is noted that Mr. Lane’s (2003) Audit stated that Arsenic was naturally elevated in the regional soils. As such, the elevated levels of Arsenic are most likely related to either natural background levels in residual soils or isolated relatively minor exceedances in the case of the sand fill;



Barium: The one isolated Barium exceedance was detected at a depth of 0.4m-0.5m, within residual clays. There is no evidence of a historical source of Barium contamination and Barium was detected at a low concentration (31mg/kg) in overlying soils, which is no indicative of a spill/leak of a Barium containing product. As such, the Auditor considers that the elevated Barium is likely to be related to natural background conditions;

Manganese & Nickel: The elevated Manganese and Nickel concentrations were associated with crushed rock (basalt) material or residual soils derived from basalt. Based on the Auditor’s experience with other properties underlain the Newer Volcanics unit, it is considered that the levels of Manganese and Nickel detected in the crushed rock can be attributed to natural background levels;

Lead: The source of the elevated concentration of Lead (600mg/kg) in residual clay sample GW06-GW1-2 is not clear as the overlying sample detected Lead at a concentration of 63mg/kg. However, as the detection is only 10mg/kg above the EIL, the sample occurs at 0.5m depth and Lead was not detected above the EIL in other remnant soil samples, the Auditor does not consider the exceedance to be significant;

Zinc: The single Zinc exceedance is not considered to be significant as the exceedance was minor (230mg/kg vs. the EIL of 200mg/kg) and there is no evidence of a historical source of Zinc contamination.

In addition to the discussion provided above, the Auditor does not consider the EIL exceedances to be significant due to the following:

EPAV have indicated that the use of statistics (i.e. mean) may be appropriate when assessing soils data against EIL’s. In accordance with EPAV guidance, the EIL exceedances are not considered to be significant as the average concentration of Arsenic, Barium, Manganese, Lead, Nickel and Zinc in remnant soils was below the respective EIL’s ;

In addition, it is noted that based on the advice provided by the Auditor’s expert support person Dr.Robert van de Graaff of Van de Graaff & Associates Pty Ltd for previous Audits at other properties located upon the Newer Volcanics unit, the regional residual clays are typically carbonate rich where Heavy Metals typically occur as low solubility carbonate compounds (e.g. ZnCO3), which significantly reduces potentially phytotoxic effects; and

Based on the above, the Auditor considers that the objectives of this beneficial use have been met.

9.7.2. Human health With the exception of Lead at a concentration of 610mg/kg in a sample collected from location GW1 (south eastern corner) at a depth of 0.4m-0.5m. As discussed in Section 9.6.1, the sample containing significantly elevated Lead is likely to be limited to the immediate vicinity of sampling location GW1. It is further noted that the NEPM (1999) HIL A criteria are based on conservative assumptions (i.e. dermal and ingestion exposure for 70 years from birth for 24 hours per day) which are highly unlikely to be realised and only intended to be used as a screening criteria.




9.7.3. Buildings and structures No data has been provided which indicates whether remnant soils are likely to be significantly detrimental to future buildings and structures. It is noted that remediation works have resulted in remnant soils predominantly containing no significant impacts for historical activities at the Site, with the exception of some minor remnant PAH and Heavy Metal impacts. As such, it is considered unlikely that Site activities have lead to contamination of land potentially leading to significant detrimental effects to future buildings and/or structures.

Based on limited pH data (between approximately 6 & 9) and low Chloride (40mg/kg) and Sulphate (20mg/kg) results from the Auditor’s verification sample, it is considered unlikely that the remnant likely soils are likely to be naturally significantly detrimental to buildings and structures.


9.7.4. Aesthetics The Site has been remediated based on analytical results as well as aesthetics (primarily odorous TPH impacted soils). The Auditor considers that it is unlikely that aesthetically unsuitable materials remain at the Site. As such, the Auditor considers that the objectives of this beneficial use have been met.

9.7.5. Production of food, flora and fibre Based on the discussion of EIL exceedances presented in Section 9.6.1, the Auditor considers that the objectives of this beneficial use have been met.

9.8. Implication of Soil Analytical Results – Offsite Migration

As remediation works have lead to remnant soils not containing contamination which is not significant with respect to risks to the environment and human health, the potential for significant offsite migration of contamination is considered to be low.



10. EVALUATION OF GROUNDWATER ANALYTICAL RESULTS

10.1. Beneficial Uses Assessment

SEPP (Groundwaters of Victoria) lists the protected beneficial uses of groundwater in Victoria. The uses to be protected are based on the salinity (measured as Total Dissolved Salts, TDS) as shown on the following table.

Table 10.1.1 - Protected Beneficial Uses of Groundwater (reproduced from SEPP 1997)

SEGMENTS (mg/L TDS)

A2

(501-1,000)

B

(1,001-3,500)

C (3,501-13,000)

BENEFICIAL USES A1 D

(0-500) (>13,000)

1. Maintenance of Ecosystems X X X X X

2. Potable Water Supply

a) Desirable X

b) Acceptable X

3. Potable Mineral Water X X X

4. Agriculture, parks and gardens X X X

5. Stock watering X X X X

6. Industrial water use X X X X X

7. Primary contact recreation

(eg. bathing, swimming) X X X X

8. Buildings and structures X X X X

X

SEPP (Groundwaters of Victoria) provides water quality indicators for each of the beneficial uses and these are summarised in the table below.

Based on field measurements of groundwater beneath the Site the groundwater is likely to be classified as Segment A2 in accordance with SEPP (Groundwaters of Victoria). As such, the following beneficial uses may require protection:

Maintenance of Ecosystems;

Potable supply water (acceptable);

Potable mineral water;

Agriculture, parks and gardens;



Stock watering;

Industrial water use;

Primary contact recreation; and

Buildings and structures.

10.2. Relevance of Beneficial Uses

It is noted that the uses determined by the SEPP (Groundwaters of Victoria) may not be relevant where:

There is insufficient yield;

The background level of water quality indicator other than TDS precludes a beneficial use;

The soil characteristics preclude a beneficial use; and

A groundwater quality restricted use zone has been declared.

The relevance of the beneficial uses noted in the preceding section are summarised in Table 10.2 below which shows that the only relevant beneficial use is Maintenance of Ecosystems.

Table 10.2 Relevance of Beneficial Uses

Beneficial Uses Relevance

Maintenance of Ecosystems; Yes.

A small tributary to Yarrowee Creek is a relevant fresh water receptor located 50m south of the site.

Potable supply water No.

It is considered unlikely that groundwater in the basalt aquifer would be used for domestic purposes given the depth to groundwater (9m) and the low permeability of the aquifer strata (plastic clays).

Potable mineral water; No.

The site is not in a recognised mineral water province.

Agriculture, parks and gardens; No.

It is considered unlikely that groundwater in the basalt aquifer would



be used for domestic purposes given the depth to groundwater (9m) and the low permeability of the aquifer strata (plastic clays).

Stock watering; No.

It is considered unlikely that groundwater in the basalt aquifer would be used for domestic purposes given the depth to groundwater (9m) and the low permeability of the aquifer strata (plastic clays). The residential nature of the surrounding area and the proposed zoning suggest that this beneficial use is unlikely.

Industrial water use; No.

It is considered unlikely that groundwater in the basalt aquifer would be used for domestic purposes given the depth to groundwater (9m) and the low permeability of the aquifer strata (plastic clays). The residential nature of the surrounding area and the proposed zoning suggest that this beneficial use is unlikely.

Primary contact recreation; and No.

It is considered unlikely that groundwater in the basalt aquifer would be used for domestic purposes given the depth to groundwater (9m) and the low permeability of the aquifer strata (plastic clays).

Buildings and structures. No.

The water table (at 9m depth) is well below the zone where it may come in contact with foundations.

10.3. Summary of Groundwater Analytical Results

Full analytical results have not been made available for the groundwater sampling undertaken within the Site (i.e GW3, adjacent to central portion of Site’s western boundary) by Diomides & Associates during 2003 as part of Mr. Lane’s (2003) audit. The following presents a summary of the information presented in Mr. Lane’s (2003) audit report:



Nitrate was detected in GW3 at a concentration of 5mg/L (which is above the protection of ecosystems based criteria of 0.7mg/L), in comparison to detections of 18.5mg/L and 23mg/L for the wells located within the property adjacent to the western boundary of the Site;

Zinc was detected in GW3 at a concentration of 6µg/L (which is below the protection of ecosystems based criteria of 8µg/L), in comparison to detections of 3µg/L and 5µg/L for the wells located within the property adjacent to the western boundary of the Site.

No other discussion of groundwater results was provided in Mr. Lane’s (2003) audit report.

The following table presents a summary of the groundwater analytical results with respect to the relevant assessment criteria for the sampling undertaken by BW during 2006.

Table 10.2.1 – Evaluation of Groundwater Analytical Results - (mg/L)

Analyte GW1 GW2 Ecosystem Protection

21/06/2006 20/06/2006 Date Sampled

490 630 TDS Chloride 79 72 Sulphate 29 49

pH (-log H+) 7.2 7.6 Arsenic 0.013 0.0026 0.0015 Boron 0.37 <0.001 0.32 Barium 0.032 0.15

Beryllium <0.001 <0.001 Cadmium 0.0002 <0.0005 <0.0005

Cobalt 0.005 <0.001 Chromium 0.001 0.003 0.003

Copper 0.0014 0.004 0.006 Mercury 0.0006 <0.0005 <0.0005

Manganese 1.7 0.29 0.002 Molybdenum 0.002 <0.001

Nickel 0.011 0.02 0.008 Lead 0.0034 <0.005 <0.005

Antimony <0.001 0.003 Selenium 0.011 0.0021 0.0038

Tin 0.002 0.002

Heavy Metals

Zinc 0.008 <0.001 0.23 C6-C9 <0.04 <0.04

TPH TPH C6-C36 ND ND



Analyte GW1 GW2

Date Sampled

Ecosystem Protection

21/06/2006 20/06/2006

Benzene 0.95 <0.001 <0.001 Toluene 0.18 <0.001 <0.001

Ethylbenzene 0.08 <0.001 <0.001 Total Xylenes 0.625 <0.001 <0.001

Styrene <0.001 <0.001 Cumene <0.001 <0.001

Monocyclic Aromatic

Hydrocarbons

<0.001 <0.001 1,2,4 Trimethylbenzene Total Polycyclic Aromatic Hydrocarbons ND ND Total Organochlorine Pesticides ND ND Total Polychlorinated Biphenyls ND ND Total Volatile Halogenated Hydrocarbons ND ND Total Chlorinated Hydrocarbons ND ND Fluoride <0.3 0.8 Cyanide <0.005 <0.005 Nitrate Nitrogen 0.7 3.1 13 Total Phenols 0.32 ND ND

na not analysed nd Not detected PQL Practical Quantitative Limits Concentration exceeds Ecosystem Maintenance Criteria

10.4. Implication of Groundwater Results – Impact to Relevant Beneficial Uses

Based on the review of the benefical uses in section 10.2 the only one considered to be relevant was Maintenance of Ecosystems and this is discussed below.

10.4.1. Maintenance of Ecosystems Chromium, Copper, Nickel, Zinc and Nitrate have been detected at concentrations exceeding the ANZECC (2000) maintenance of fresh water ecosystems based criteria. The remaining contaminants of concern were not detected above this criteria. The following presents an assessment of the significance of the Chromium, Copper, Nickel, Zinc and Nitrate detections.

Chromium, Copper, Nickel and Zinc

Leachability testing has not been completed to provide a reasonable assessment of Heavy Metal concentrations in seepage water passing through the fill material and consequently assess the likely contribution of migration of Heavy Metals from the fill.

However, Heavy Metals related contamination at the Site has primarily been limited to the fill material, or the upper portions of natural soils immediately underlying the fill. The Auditor considers that it is unlikely that leaching of Heavy Metals within the fill may have lead to significant impacts upon groundwater quality as there is in the order of 8m of residual soil / weathered rock between the deepest identified Heavy Metal contamination and the observed groundwater table.

It is also noted that no levels of these contaminants exceeded the HIL’s and only nickel and zinc slightly exceeded the EIL’s in the soils.



Based on the above, the Auditor considers that it is unlikely that the levels of Chromium, Copper, Nickel and Zinc detected in groundwater can be attributed to Site originated contamination. It is noted that various Heavy Metals are commonly detected in groundwater at levels exceeding ANZECC (2000) maintenance of fresh water ecosystems based criteria, which are based on protecting surface water bodies. This represents a limitation with the application of these guidelines for assessing whether significant groundwater contamination has occurred.

Nitrate

The available Site history information does not indicate any historical Nitrate sources at the Site or in the immediate vicinity of the Site. Mr. Lane’s (2003) audit report indicates that Nitrate concentrations in groundwater beneath the property to the west of the Site were indicative of a source to the west, with Nitrate detected at 5mg/L adjacent to the common boundary with the Site and 18mg/L to 23mg/L in the western portion of the property.

Based on the above, the Auditor considers that the occurrence of Nitrate is likely to be attributable to natural background conditions or an offsite contamination source, and unlikely to be attributable to historical Site activities.

10.5. Note Regarding Inappropriate PQL’s

It is noted that the PQL’s for a number of the contaminants of concern were inappropriately high and above a number of relevant criteria, namely:

PAH:

Anthracene;

Benzo(a)pyrene;

Fluoranthene.

OCP:

Lindane;

Heptachlor;

Heptachlorepoxide;

Dieldrin;

DDT;

Methoxychlor;

Chlordane;

a-Endosulphan;

b-Endosulphan.

PCB;



VHC:

Dichloromethane;

1,1-Dichloroethene;

Vinyl Chloride.

CHC

Hexachlorobutadiene.

Soil data indicates that PCB, OCP, VHC and CHC related contaminants are unlikely to have been present at a significant concentrations at the Site (not detected above PQL’s). As such, the PCB, OCP, VHC and CHC PQL inadequacies are not considered to be significant for the purposes of the Audit.

PAH’s have been detected at significant concentrations in near surface soils, however, there is approximately 3m of low permeability residual clays and 5m of weathered basalt between the base of identified significant PAH contamination and the groundwater table. As such, the Auditor considers that it is unlikely that PAH’s may have migrated to the groundwater table and resulted in significant groundwater contamination.

10.6. Clean Up to the Extent Practical CUTEP

Based on the review of the results presented in the preceding sections there is the potential for the Maintenance of Ecosystems beneficial uses to be impacted due to the presence of Heavy Metals and nitrate in groundwater at the Site.

However the impact on the maintenance of ecosystems due to the exceedances of the criteria is considered to be minimal due to the following:

• The ANZECC 2000 levels are only trigger levels and do not take into account any attenuation of contaminant levels; and

• The levels are likely to be indicative of background levels and not Site related.

Therefore remediation of the groundwater is not considered necessary and clean up to the extent practical is considered to have occurred.



11. CONCLUSIONS AND RECOMMENDATIONS

Based on the findings of the Audit, the Auditor concludes the following:

BW adequately identified potential historic potentially contaminating activities which occurred at the Site and undertook appropriate investigations (soil and groundwater);

BW’s investigations revealed the presence of Arsenic, Lead, PAH and Benzo(a)pyrene at concentrations exceeding NEPM (1999) HIL A criteria, rendering the Site unsuitable for the proposed low density residential use. Soil remediation and validation works were subsequently undertaken;

The Auditor’s review of the remediation and validation has revealed that the remedial activities have been successfully undertaken;

The following presents a summary of the status of the objectives of the relevant beneficial uses of land, as per SEPP (Prevention and Management of Contamination of Land):

Ecosystem maintenance (modified ecosystems) – objectives met;

Human health – objectives met;

Buildings and structures – objectives met;

Aesthetics – objectives met;

Production of food, flora and fibre – objectives met.

• The groundwater investigations revealed the presence of Chromium, Copper, Manganese, Nickel, Zinc and Nitrate at concentrations exceeding the criteria for the only relevant beneficial use as per SEPP (Groundwaters of Victoria) which was Maintenance of Ecosystems. However these levels are representative of background levels and it is considered unlikely that this beneficial use is impacted.

Based on the above, the Auditor considers it appropriate to issue a Certificate of Environmental Audit.



12. OTHER RELEVANT INFORMATION

This Audit was conducted on the behalf of the Client for the purpose of assessing what investigation or remediation is necessary before the land is suitable for residential purposes, as contemplated in Part IXD of the Environment Protection Act, 1970. The Consultant included limitations in their report. The Audit must also be subject to those limitations. The Auditor has prepared this document in good faith, but is unable to provide certification outside of areas over which he had some control or is reasonably able to check.

It is not possible in an Environmental Audit Report to present all data, which could be of interest to all readers of this report. Readers are referred to the referenced investigation reports for further data. Users of this document should satisfy themselves concerning its application to, and where necessary seek expert advice in respect to, their situation.

The Auditor notes that any comments and conclusions provided in this document regarding the suitability of the Site for the proposed landuse are implicitly limited to consideration of Contamination related issues as defined under the Environment Protection Act 1970.


Mihaljevic Constructions Pty Ltd · Environmental Audit Report 37 Orion Street (rear), Sebastopol,...

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