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STC-886-12926 / RAP1v1 draft 18th October 2017

Remediation Action Plan

280 Garfield Road East and 259 Riverstone Road, Riverstone NSW

Prepared for: Sunglow Development Management Pty Ltd C/- Orion Consulting Engineers

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Remediation Action Plan 280 Garfield Road East and 259 Riverstone Road, Riverstone NSW Prepared for:

Sunglow Development Management Pty Ltd C/- Orion Consulting Engineers

Report No: STC-886-12926 / RAP1 / v1 draft Date: 18th October 2017 Written by: Edward Moss

B.Sci. Hons (Geology) Environmental Consultant Reviewed by:

Justin Eccles M. Sci. Tech (Env. Sci.)

Senior Environmental Consultant

Version Details Date v1 draft Written by Edward Moss 18th October 2017

This report is copyright. No part of this publication may be reproduced or transmitted in any form or by any

means, electronic or mechanical, including photocopying without permission in writing from ADE Consulting

Group Pty Ltd.


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TABLE OF CONTENTS

1. EXECUTIVE SUMMARY .................................................................................................................................. 8

1.1. Background.................................................................................................................................................... 8 1.2. Proposed Development................................................................................................................................. 8 1.3. Objectives of the RAP .................................................................................................................................... 9 1.4. Scope of Works.............................................................................................................................................. 9 1.5. Legislative Requirements ............................................................................................................................ 10 1.6. Whole Report .............................................................................................................................................. 10

2. SCOPE OF WORKS ........................................................................................................................................ 11

3. SUMMARY OF PREVIOUS REPORTS ............................................................................................................. 12

3.1. ‘Geotechnical / Salinity Investigation,’ ADE report no. STC-754-12439 / GTI1 / v1 final dated 12th September 2017’ (ADE 2017a) .................................................................................................................... 12

3.2. ‘Phase I Preliminary Site Investigation’, ADE report no. STC-746-12411 / PSI1 / v1 final, report dated 25th August 2017 (ADE 2017b) ........................................................................................................................... 12

3.3. ‘Phase I Preliminary Site Investigation and Phase II Detailed Site Investigation’’, ADE report no. STC-745-12410 / DSI1 / v1 final, report dated 18th October 2017 (ADE 2017c) ....................................................... 13

3.4. ‘Waste Analysis and Classification Report’, ADE report no. STC-745-12410 / WAC1 / v1 draft, report dated 18th October 2017 (ADE 2017d) ........................................................................................................ 17

3.5. ‘Waste Analysis and Classification Report’, ADE report no. STC-745-12410 / WAC2 / v1 draft, report dated 18th October 2017 (ADE 2017e) ........................................................................................................ 18

4. SITE IDENTIFICATION ................................................................................................................................... 19

4.1. Site Identification and Description .............................................................................................................. 19 4.2. Site Plans ..................................................................................................................................................... 19 4.3. Locality Maps and Key Site Observations.................................................................................................... 20

5. SITE CONDITION AND SURROUNDING ENVIRONMENT .............................................................................. 22

6. REVIEW OF SITE HISTORY ............................................................................................................................ 24

7. GEOLOGY AND HYDROGEOLOGY ................................................................................................................ 28

7.1. Soil Stratigraphy .......................................................................................................................................... 28 7.2. Location and Extent of Imported and Locally Derived Fill .......................................................................... 29

7.2.1. Fill Wedge 1 (F1) – Fill Type 1 ................................................................................................................................ 29 7.2.2. Fill Wedge 1 (F1) – Fill Type 2 ................................................................................................................................ 29 7.2.3. Dam 1 (D1) – Fill Type 3 ......................................................................................................................................... 30 7.2.4. Dam 1 (D1) – Fill Type 4 ......................................................................................................................................... 30

7.3. Regional Setting........................................................................................................................................... 31

8. REMEDIATON ASSESSMENT CRITERIA ........................................................................................................ 33

8.1. Health Investigation Levels (HILs) ............................................................................................................... 33 8.2. Health Screening Levels (HSLs) .................................................................................................................... 33 8.3. Management Limits .................................................................................................................................... 34 8.4. Asbestos ...................................................................................................................................................... 37


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8.5. Groundwater Investigation Levels .............................................................................................................. 37 8.6. Scope of Ecological Assessment .................................................................................................................. 37 8.7. Waste Analysis and Classification ............................................................................................................... 38 8.8. Aesthetics .................................................................................................................................................... 39 8.9. Statistical Analysis ....................................................................................................................................... 39 8.10. Duty to Report Contamination .................................................................................................................... 40

8.10.1. On-site Soil Contamination ........................................................................................................................... 40 8.10.2. Asbestos, in, or on, Soil ................................................................................................................................ 40

9. SITE CHARACERISATION .............................................................................................................................. 42

10. REMEDIAL ACTION PLAN ............................................................................................................................. 45

10.1. Extent of Remediation Required ................................................................................................................. 45 10.1.1. Known Extent ............................................................................................................................................... 45 10.1.2. Unknown Extent ........................................................................................................................................... 45

10.2. Remediation Options .................................................................................................................................. 45 10.3. Remediation Rationale ................................................................................................................................ 46 10.4. Recommended Remediation Option........................................................................................................... 47

10.4.1. Off Site Disposal............................................................................................................................................ 47 10.4.2. Re-Use on Site .............................................................................................................................................. 47

10.5. Remediation Works Plan ............................................................................................................................. 48 10.6. Roles and Responsibilities ........................................................................................................................... 48 10.7. Preliminaries and Approvals ....................................................................................................................... 49 10.8. Remediation – Prior to Earthworks ............................................................................................................. 49

10.8.1. Survey of 44 Gallon Drums / Mauser Containers ......................................................................................... 49 10.8.2. Dewatering Management Plan ..................................................................................................................... 49 10.8.3. Site Preparation ............................................................................................................................................ 49 10.8.4. Surficial Sources of Contamination .............................................................................................................. 50 10.8.5. Stockpiles Generated On-Site ....................................................................................................................... 52 10.8.6. Subsurface Sources of Contamination ......................................................................................................... 53

10.9. Remediation – During Earthworks .............................................................................................................. 54 10.9.1. Subsurface Sources of Contamination ......................................................................................................... 54

10.10. Additional Investigations ............................................................................................................................. 56 10.10.1. Data Gaps – Base of Dams ............................................................................................................................ 56 10.10.2. Unexpected Finds – Soil and Groundwater Contamination ......................................................................... 56

11. VALIDATION AND MONITORING ................................................................................................................. 57

11.1. Validation .................................................................................................................................................... 57 11.2. Sample Collection and Holding ................................................................................................................... 57 11.3. Quality Assurance Plan ................................................................................................................................ 58 11.4. Data Quality Objectives ............................................................................................................................... 58 11.5. Soil Sampling and Visual Validation of AoC ................................................................................................. 59

11.5.1. Validation Sampling of Soils Potentially Impacted from ASTs (AoC1) .......................................................... 59 11.5.2. Validation Sampling for 44 Gallon Drum / Mauser Containers Removal (AoC2) ......................................... 59 11.5.3. Visual Clearance Inspection of ‘Bonded’ ACM on Soil Surface (AoC3 and AoC4) ......................................... 60 11.5.4. Validation Sampling of Soils Potentially Impacted from USTs (AoC5) .......................................................... 60 11.5.5. Validation Sampling for Lead Hotspot (AoC6) .............................................................................................. 61 11.5.6. Validation Sampling for ‘Bonded’ ACM Soils (>HSL D) (AoC7) ...................................................................... 61 11.5.7. Validation Sampling for ‘Bonded’ ACM Soils (<HSL D) (AoC8) ...................................................................... 62

11.6. Validation Reporting ................................................................................................................................... 63


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12. SITE MANAGEMENT PLAN ........................................................................................................................... 64

12.1. Enquiries ...................................................................................................................................................... 64 12.2. Site Provisions ............................................................................................................................................. 64 12.3. Adherence to Codes .................................................................................................................................... 64 12.4. Site Establishment ....................................................................................................................................... 64 12.5. Programming of the Works ......................................................................................................................... 64 12.6. Works on Site .............................................................................................................................................. 65 12.7. Damage to Services ..................................................................................................................................... 65 12.8. Waste Water ............................................................................................................................................... 65 12.9. Temporary fire Extinguishers ...................................................................................................................... 65 12.10. Environmental Protection ........................................................................................................................... 65 12.11. Runoff Control ............................................................................................................................................. 65 12.12. Noise Control ............................................................................................................................................... 66 12.13. Site and Dust Control .................................................................................................................................. 66 12.14. Nuisance Odour Control .............................................................................................................................. 66 12.15. Disposal of Waste ........................................................................................................................................ 66 12.16. Publicity ....................................................................................................................................................... 67 12.17. Approval to Commence Soil Removal Work ............................................................................................... 67 12.18. Authorities ................................................................................................................................................... 67 12.19. Work Practice .............................................................................................................................................. 67 12.20. Decontamination ......................................................................................................................................... 67 12.21. Contaminated Waste .................................................................................................................................. 68 12.22. Health and Safety Issues ............................................................................................................................. 68

13. CONCLUSIONS AND RECOMMENDATIONS ................................................................................................. 70

14. LIMITATIONS ............................................................................................................................................... 71

15. REFERENCES ................................................................................................................................................ 72


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LIST OF TABLES

TABLE 1 - F1 SUMMARY OF EXCEEDANCES IN SAC FOR SOIL SAMPLE ANALYSIS .................................................................... 13 TABLE 2 - D1 SUMMARY OF EXCEEDANCES IN SAC FOR SOIL SAMPLE ANALYSIS ................................................................... 14 TABLE 3 - W1 SUMMARY OF EXCEEDANCES IN SAC FOR SOIL SAMPLE ANALYSIS .................................................................. 15 TABLE 4 - 259 RIVERSTONE ROAD, RIVERSTONE SUMMARY OF EXCEEDANCES IN SAC FOR SOIL SAMPLE ANALYSIS .................... 16 TABLE 5 - GROUNDWATER SUMMARY OF EXCEEDANCES IN SAC FOR WATER SAMPLE ANALYSIS ............................................. 16 TABLE 6 - DAM SEDIMENT SUMMARY OF EXCEEDANCES IN SAC FOR SOIL SAMPLE ANALYSIS ................................................. 16 TABLE 7 - SUMMARY OF SITE IDENTIFICATION DETAILS. .................................................................................................... 19 TABLE 8 - SUMMARY OF SITE CONDITION AND SURROUNDING ENVIRONMENT. .................................................................... 22 TABLE 9 - SUMMARY OF SITE HISTORY. .......................................................................................................................... 24 TABLE 10 - SOIL SPECIFIC LITHOLOGY FOR 280 GARFIELD ROAD EAST, RIVERSTONE NSW. .................................................... 28 TABLE 11 - SOIL SPECIFIC LITHOLOGY FOR 259 RIVERSTONE ROAD, RIVERSTONE NSW. ........................................................ 29 TABLE 12 - REGIONAL SETTING FOR SITE. ....................................................................................................................... 31 TABLE 13 - REMEDIATION ASSESSMENT CRITERIA – HIL A / HSL A FOR SOIL CONTAMINATION, MG/KG (UNLESS OTHERWISE

SPECIFIED). .................................................................................................................................................. 35 TABLE 14 - REMEDIATION ASSESSMENT CRITERIA – HIL D / HSL D FOR SOIL CONTAMINATION, MG/KG (UNLESS OTHERWISE

SPECIFIED). .................................................................................................................................................. 36 TABLE 15 - ADOPTED RAC AS DETAILED IN NEPM (2013). ................................................................................................. 37 TABLE 16 - LEACHABLE CONCENTRATIONS (TCLP) AND SPECIFIC CONTAMINANT CONCENTRATIONS (SCC) VALUES FOR

CLASSIFYING WASTE BY CHEMICAL ASSESSMENT. ............................................................................................. 38 TABLE 17 - PUBLISHED AUSTRALIAN BACKGROUND SOIL CONCENTRATIONS. ....................................................................... 39 TABLE 18 - POTENTIAL SOURCES, LOCATIONS AND TYPES OF CONTAMINANTS. .................................................................... 42 TABLE 19 - LOCATION AND DESCRIPTION OF AOC ADDRESSED IN THE RAP. ........................................................................... 48 TABLE 20 - ROLES AND RESPONSIBILITIES FOR THE REMEDIATION WORKS. .......................................................................... 48

LIST OF FIGURES

FIGURE 1. CURRENT SITE PLAN FOR 280 GARFIELD ROAD EAST AND 259 RIVERSTONE ROAD, RIVERSTONE NSW (MAP ADAPTED FROM NEARMAP; ACCESSED 04.10.2017). ....................................................................................................... 20

FIGURE 2. SITE LOCALITY MAP (MAPS ADAPTED FROM SIXMAPS; ACCESSED 05.10.2017). .................................................... 21 FIGURE 3. CONCEPTUAL SITE MODEL FOR SITE. .............................................................................................................. 44


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ABBREVIATIONS

ACM Asbestos Containing Materials ADE ADE Consulting Group Pty Ltd AHD Australian Height Datum AMP Asbestos Management Plan AoC Area of Concern ASS Acid Sulfate Soils AST Above Ground Storage Tank BGL Below Ground Level

BTEX Benzene, Toluene,Ethyl-benzene, Xylene CoC Chain of Custody

COPC Contaminants of Potential Concern DBYD Dial Before You Dig DEC Department of Environment and Conservation DMP Dewatering Management Plan DQI Data Quality Indicators DQO Data Quality Objectives DSI Detailed Site Investigation

EMP Environmental Management Plan ENM Excavated Natural Material EILs Ecological Investigation Levels ESLs Ecological Screening Levels HILs Health Investigation Levels HSLs Health Screening Levels LPI Land Property Information

LT-EMP Long Term Environmental Management Plan LTO Land Titles Office

NATA National Association of Testing Authorities NEPC National Environmental Protection Council NEPM National Environmental Protection Measure

NSW EPA New South Wales Environment Protection Authority OEH Office of Environment and Heritage

OH&S Occupational Health and Safety OPPs Organophosphorous Pesticides OCPs Organochlorine Pesticides PAHs Polycyclic Aromatic Hydrocarbons PSI Preliminary Site Investigation

QA/QC Quality Assurance/Quality Control RAP Remediation Action Plan SAS Site Audit Statement SWL Standing Water Level

SH&EWMS Safety Health and Environmental Works Method Statement TCLP Toxicity Characteristic Leaching Potential TPH Total Petroleum Hydrocarbons TRH Total Recoverable Hydrocarbons UCL Upper Confidence Limit UST Underground Storage Tank VAL Validation Report

VENM Virgin Excavated Natural Material


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1. EXECUTIVE SUMMARY

1.1. Background

ADE Consulting Group Pty Ltd (ADE) was commissioned by Orion Consulting Engineers on behalf of Sunglow Development Management Pty Ltd (the ‘Client’) to prepare a Remediation Action Plan (RAP) for the properties located at 280 Garfield Road East and 259 Riverstone Road, Riverstone New South Wales (NSW) (hereafter referred to as ‘the Site’). Previous investigations identified areas of localised soil contamination and Areas of Concern (AoCs), particularly in regards to Asbestos Containing Materials (ACM) and Lead in soil. As such, the findings triggered the requirement for a Site Stage III Remediation Action Plan as per the Contaminated Land Management Act 1997 (CLM 1997). The primary objective of the RAP is to serve as a guidance document for future remediation works and to provide Remediation Assessment Criteria (RAC) as part of the remediation phase. The RAP will outline the procedures for the remediation of the Site, in order to achieve a condition suitable for the proposed future land use as low density residential properties. The RAP will also provide guidance on how the remedial strategy is to be implemented, including occupational and environmental controls to be adopted during the removal and validation of the AoCs. This report should be read in conjunction with the following reports:

‘Phase I Preliminary Site Investigation’, ADE report no. STC-746-12411 / PSI1 / v1 final, report dated 25th August 2017 (ADE 2017a); ‘Geotechnical / Salinity Investigation Report’, ADE report no. STC-754-12439 / GTI1 / v1 final, report dated 12th September 2017 (ADE 2017b); ‘Phase I Preliminary Site Investigation and Phase II Detailed Site Investigation’, ADE report no. STC-745-12410 / PSI/DSI1 / v1 final, report dated 12th May 2017 (ADE 2017c); ‘Waste Analysis and Classification Report’, ADE report no. STC-745-12410 / WAC1 / v1 draft report dated 18th October 2017 (ADE 2017d); and ‘Waste Analysis and Classification Report’, ADE report no. STC-745-12410 / WAC2 / v1 draft, report dated 18th October 2017 (2017e).

1.2. Proposed Development

The proposed construction works within the Site forms part of a larger development, which includes the subdivision of land for future residential land use. The larger development will include approximately 950 lots within the currently zoned land and the construction of facilitating roads. The total development undertaken across the Site has total footprint of approximately 60 hectares (ha). The design will incorporate local roads and residential lots ranging between 260 m2 to approximately 800 m2 in size. Final design is not yet complete, however, cut and fill activities are planned across the Site with excavations extending to approximately 2.5 m below the current ground level (BGL - refer to Appendix II – Development Plans). Deeper excavations extending to natural ground level are expected adjacent the warehouse in the central portion of 280 Garfield Road East to approximately 4.5 m BGL.


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1.3. Objectives of the RAP

The objectives of the RAP are to:

(i) Describe the works and methodologies essential to remediate the Site to a standard suitable for the proposed future land use as low density residential properties; and

(ii) Provide an appropriate scope of validation works sufficient to demonstrate that the Site has been successfully remediated. The works should be carried out in a manner to minimise the potential harm to both human health and the environment.

Therefore, the RAP provides the following strategy for Site remediation:

Set soil remediation goals to such an extent that enables the consultant to ensure that the remediated Site is suitable for the proposed development and will pose no unacceptable risk to human health or the environment with regards to the Contaminants of Potential Concern (CoPC); Propose a cost effective and practical soil remediation strategy; Document in detail all procedures and plans to be implemented to reduce risks to acceptable levels for the proposed Site use; Establish environmental safeguards required to complete the remediation in an environmentally acceptable matter; and Comply with the relevant regulatory guidelines.

Following the completion of the remediation works, a Stage IV Validation Report will be submitted for review by the Site Auditor, and will form part of a non-statutory Site Audit Statement (SAS) and Report.

1.4. Scope of Works

The scope of work required to achieve the objectives of the RAP involves the following:

Summarise Site conditions and surrounding environment; Summarise the current contamination status for the Site; Identify regulatory requirements, including licences and approvals required for the remediation works to commence; Establish remediation goals to ensure the Site will be suitable for the proposed future land use and will pose no long term risk to human health and/or the environment; Define the extent of remediation required; Prepare a detailed description of the remediation approach, including capping design (if required), environmental and Occupational Health and Safety (OH&S) controls to be implemented during the excavation and movement of impacted soil materials. This will be undertaken in order to minimise both short and long term risks at the Site; Establish Site validation requirements; and Develop an unexpected finds protocol that establishes procedures to be followed in the event that previously unexpected contamination sources are identified during remediation works.


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1.5. Legislative Requirements

The legislative framework for the RAP is based on the guidelines that have been issued and by the NSW Environment Protection Authority (EPA) under the following Acts / Policies:

CLM (1997); Protection of the Environment Operations Act 1997 (POEO Act); and State Environmental Planning Policy No 55—Remediation of Land 1998 (SEPP 55).

The relevant guidelines based on the aforementioned are as follows:

Australian Standard AS 4482.1 Guide to the sampling and investigation of potentially contaminated soil. Part 1: Non-volatile and semi-volatile compound, 2005; Australian Standard AS 4482.2 Guide to the sampling and investigation of potentially contaminated soil. Part 2: Volatile substances, 2005; Department of Environment and Conservation (DEC) Guidelines for the NSW Site Auditor Scheme, NSW, Second Edition (DEC 2006); Guidelines on the Duty to Report Contamination under the Contaminated Management Act 1997; National Environmental Protection Council (NEPC) National Environmental Protection (Assessment of Site Contamination) Measure 1999, 2013 Amendment (NEPM 2013); NSW Office of Environment and Heritage (OEH) Guidelines for Consultants Reporting on Contaminated Sites (OEH 2011); NSW EPA Sampling Design Guidelines, (NSW EPA 1995); NSW EPA Waste Classification Guidelines Part 1: Classifying Waste (NSW EPA 2014); Work Health and Safety Act 2011; Work Health and Safety Regulation 2017; WorkCover NSW – Managing asbestos in or on soil (2014); SafeWork NSW: How To Manage And Control Asbestos In The Workplace (2016); and SafeWork NSW Code of Practice: How to Safely Remove Asbestos (2016).

1.6. Whole Report

No one section or part of a section, of this plan should be taken as giving an overall idea of this plan. Each section must be read in conjunction with the whole of this plan, including its appendices and attachments.


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2. SCOPE OF WORKS

The scope of works required to achieve the objectives of the RAP involves the following:

Summarise previous investigation reports related to the Site; Summarise Site conditions and surrounding environment, history and geology / hydrogeology; Summarise the current contamination status for the Site and discuss the extent of remediation required; Identify regulatory requirements, including licences and approvals required for the remediation works to commence; Establish remediation goals to ensure the Site will be suitable for the proposed future land use and will pose no long term risk to human health and / or the environment; Define the extent of remediation required; Prepare a detailed description of the remediation approach, environmental and OH&S controls to be implemented during the excavation and movement of contaminated soil materials (where required); and Preparation of RAP incorporating the above.


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3. SUMMARY OF PREVIOUS REPORTS

The following section summarises the previous investigations undertaken within the Site:

3.1. ‘Geotechnical / Salinity Investigation,’ ADE report no. STC-754-12439 / GTI1 / v1 final dated 12th September 2017’ (ADE 2017a)

ADE was engaged to undertake a geotechnical investigation across 280 Garfield Road East, Riverstone and 259 Riverstone Road, Riverstone between the 4th July 2017 and 17th July 2017. The summary of this report pertaining to this investigation is listed below:

Sixty-one (61) boreholes, BH01 to BH61 were advanced throughout the Site to depths of 3.0 m to 6.0 m below ground level (BGL) or refusal with one (1) borehole, BH16 extending to 9.0 m BGL due to the subsurface conditions encountered; Subsurface conditions at the proposed site were summarised on borehole logs and predominantly consisted of TOPSOIL, Gravelly SAND and Silty CLAY FILL, and Silty CLAY (RESIDUAL) overlying extremely weathered SHALE BEDROCK. The clay soils encountered at the Site varied from low to high plasticity. Groundwater was encountered at depths ranging from 1.5 m to 5.4 m BGL during the course of the investigation; After stripping of topsoil and shallow fill materials, ADE anticipated that overall the majority of the Site could be preliminarily classified as moderately to highly reactive, Class “M” to “H” in accordance with the Australian Standard (AS) 2870-2011 Residential Slabs and Footings; Further geotechnical investigation and advice should be sought for remediation and backfilling of the existing reservoirs. This investigation should include assessment of soil conditions within the reservoir interior floor regarding sediment thickness accumulated over time, the presence and depth of soft/wet soils and appropriate development requirements; The Site is feasible for shallow footings to support residential buildings up to two-storey in height, except for the Class P areas identified with undocumented fill soils; and The soil tested was classified as predominantly non saline to moderately saline with one (1) sample resulting in a very saline soil. Soils were determined to be non-aggressive to steel, non to mildly aggressive to concrete and sodic to highly sodic. Management strategies are recommended due to the soil sodicity.

3.2. ‘Phase I Preliminary Site Investigation’, ADE report no. STC-746-12411 / PSI1 / v1 final, report dated 25th August 2017 (ADE 2017b)

ADE was engaged to undertake a Preliminary Phase I Investigation (PSI) within the Site at 259 Riverstone, Riverstone between the 5th July 2017 and 10th July 2017. Based on the data and evidence collected from the PSI the following conclusions can be made:

Historical aerial photographs and Land Titles Office (LTO) records indicate that the Site was predominantly used for market gardens between 1991 to present day, before which the Site was used for low density residential / pastureland; A desktop study, limited sampling and site investigation indicated that the Site was suitable for the proposed land-use. No results exceeded the HIL - A criteria for for residential land-use with accessible soils (as per NEPM 2013);


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Asbestos was detected in three (3) of the four (4) fibre cement samples collected from the soil surface of the old residential building footprint immediately north of the green shed. ACM were considered to be limited to the soil surface and isolated stockpile containing building debris, associated with previous building demolition; Based on the limited occurrence of ACM, it is considered that an emu pick of the affected area and the disposal of the building rubble and associated soil materials located within the AOC are required to address the asbestos contamination. A waste classification of the stockpiled materials prior to off-site disposal to a licensed waste facility is required; and Several areas were inaccessible to ADE at the time of inspection namely the area beneath the greenhouse and concrete slabs adjacent to the green shed. Taking the above into consideration, a Limited Detailed Site Investigation / Supplementary Limited Investigation is required within these areas, once accessible.

3.3. ‘Phase I Preliminary Site Investigation and Phase II Detailed Site Investigation’’, ADE report no. STC-745-12410 / DSI1 / v1 final, report dated 18th October 2017 (ADE 2017c)

ADE was engaged to undertake a combined PSI and Phase II Detailed Site Investigation (DSI) to assess the current level of contamination (if any) within the property located at 280 Garfield Road East, Riverstone NSW. Sample locations which exceed the adopted SAC are shown in the following tables relevant to each area of investigation. Areas requiring remediation / management are shown in Appendix I – Areas of Concern.

Fill Wedge 1 - Heavy Metals and ‘Bonded’ ACM in Soil Table 1 - F1 Summary of Exceedances in SAC for Soil Sample Analysis

Sample ID Depth m BGL Analyte

Site Assessment Criteria (HIL-A /

HSL-A)

Site Assessment Criteria (HIL-D /

HSL-D)

Concentration Detected

Requires Remediation / Management

Soil

F1.TP5A 0.3 Lead 300 (mg/kg) N/A 870 (mg/kg) Yes (exceeds HIL-A)1

F1.TP24A 0.3 Lead 300 (mg/kg) N/A 570 (mg/kg) No2

F1.TP19A 0.3 Carcinogenic PAH 3 (mg/kg) N/A 4.8 (mg/kg) No3

F1.TP29C 1 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.04% (w/w) Yes (exceeds HSL A)

F1.TP37G 3 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.02% (w/w) Yes (exceeds HSL A)

F1.TP38E 2 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.05% (w/w) Yes (exceeds HSL A)



F1.TP48E 2 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.04% (w/w) Yes (exceeds HSL A)


12410-F1.TP43C-NEPM 1 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.01% (w/w) Yes (asbestos detected)

12410-F1.TP46G-NEPM 3 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.01% (w/w) Yes (asbestos detected)

12410-F1.TP46I-NEPM 4 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.01% (w/w) Yes (asbestos detected)

12410-F1.TP48I-NEPM 4 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.01% (w/w) Yes (asbestos detected)


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Table 1 - Continued...



HSL-A)


HSL-D)



Soil

F1-TP4G 3 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP17C 1 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP24C 1 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP25E 2 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP28C-FC 1 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP34E-FC 2 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)




F1-TP48D-FC 1.5 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP49D-FC 1.5 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected)

F1-TP50E-FC 2 ‘Bonded’ ACM N/A N/A N/A Yes (asbestos detected) Notes to Table: 1 95% UCL was not deemed appropriate given the concentration of lead was greater than 2.5 times the SAC 2 95% UCL for the F1 dataset gave a value of 181.8 mg/kg for lead, below the adopted SAC 3 95% UCL for the F1 dataset gave a value of 0.947 mg/kg for carcinogenic PAH, below the adopted SAC

Fill Wedge 1 - Stockpiled Soil Materials

The concentrations of Heavy Metals, TRH, BTEX, PAHs, PCBs, OCPs and OPPs in the soil samples collected from the subject stockpile meet the NSW EPA criteria assigned for ‘Restricted Solid Waste’ with the potential for ‘General Solid Waste’ following TCLP analysis for Benzo(a)pyrene; and Currently the stockpiled soil materials are classified for off-site disposal in accordance with the NSW EPA (2014) as ‘Special Waste – Bonded Asbestos (as Restricted Solid Waste)’.

Dam 1 - ‘Bonded ACM’ in, or on, Soil Table 2 - D1 Summary of Exceedances in SAC for Soil Sample Analysis


Site Assessment

Criteria (HIL-A / HSL-A)


HSL-D)



Soil

D1.TP13C 1 Lead 300 (mg/kg) N/A 540 (mg/kg) No1

D1.TP2B 0.5 Carcinogenic PAH 3 (mg/kg) N/A 5.2 (mg/kg) No2

D1.TP23A 0.3 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.13% (w/w) Yes (exceeds HSL-A & HSL-D)

D1.TP23E 2 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.07% (w/w) Yes (exceeds HSL-A & HSL-D)

D1.TP24E 2 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.02% (w/w) Yes (exceeds HSL-A)

D1.TP24I 4 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.01% (w/w) Yes (asbestos detected)

D1.TP24K 5 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.05% (w/w) Yes (exceeds HSL-A)


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Table 2 - Continued...


Site Assessment

Criteria (HIL-A / HSL-A)


HSL-D)



Soil

D1.TP29C 1 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.03% (w/w) Yes (exceeds HSL-A)

D1.TP29I 4 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.02% (w/w) Yes (exceeds HSL-A)

D1-32C-FC-NEPM 1 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.01% (w/w) Yes (asbestos detected)

D1.TP32E 2 ‘Bonded’ ACM 0.01% (w/w) 0.05% (w/w) 0.02% (w/w) Yes (exceeds HSL-A) D1, dam eastern embankment, adjacent to storage racks, soil surface

Soil Surface

All Forms of Asbestos

No Asbestos on Soil Surface


Asbestos on Soil Surface Yes (exceeds HSL-A & HSL-D)

Notes to Table: 1 95 % UCL for the D1 dataset gave a value of 169.6 mg/kg for lead, below the adopted SAC 2 95% UCL for the D1 dataset gave a value of 1.339 mg/kg for carcinogenic PAH, below the adopted SAC

Warehouse 1 - Heavy Metals in Soil Table 3 - W1 Summary of Exceedances in SAC for Soil Sample Analysis



HSL-A)


HSL-D)



Soil

W1.BH11A 0.3 Chromium 100 (mg/kg) N/A 110 (mg/kg) No1 Notes to Table: 1 95% UCL for the W1 dataset gave a value of 21.5 mg/kg for chromium, below the adopted SAC

Paddocks 1 to 4 Contamination Concentration of Heavy Metals, TRH, BTEX, PAHs, PCBs, OCPs and OPPs within all samples collected were below the SAC (HIL-A).

259 Riverstone Road, Riverstone - ‘Bonded ACM’ in, or on, Soil Asbestos was detected within three (3) fibre cement samples collected from the central portion of the property. The ACM is limited to the soil surface and an isolated stockpile containing building debris likely attributed to previous building demolition in the area.


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Table 4 - 259 Riverstone Road, Riverstone Summary of Exceedances in SAC for Soil Sample Analysis

Sample Location

Depth m BGL Analyte Site Assessment

Criteria (HSL-A) Site Assessment Criteria (HSL-D)



Soil Surface

Centre of property, old building footprint, soil surface

Soil Surface

All Forms of Asbestos



Asbestos on Soil Surface Yes (exceeds HSL-A & HSL-D)

Groundwater Contamination

Nickel and Zinc detections are likely due to interaction of the standing groundwater table (3.0 m BGL) with natural soil materials of the Ashfield Shale geology and unlikely to be a localised contamination event. Furthermore, soil samples within the vicinity of BH2 do not contain concentrations of Nickel and Zinc above the adopted SAC. The groundwater was observed to be saline (brackish) and therefore is not considered suitable to remain on-site for the future land use or human consumption. Table 5 - Groundwater Summary of Exceedances in SAC for Water Sample Analysis


ANZECC (2000) Guidelines for

Freshwater Quality

NEPM 2013 Groundwater

HSLs for Vapour Intrusion



Groundwater

GW-BH2 N/A Nickel 11 ( g/L) N/A 16 ( g/L) No

GW-BH2 N/A Zinc 8 ( g/L) N/A 32 ( g/L) No

Sediment Contamination

Concentrations of all analytes in the sediment samples collected from all dams were below the SAC except for 12410-D3.South (Arsenic - of 37 mg / kg. Given this arsenic exceedance was localised to one sampling location and is below the adopted ISQG-High SAC, it is considered suitable for the proposed future development. Table 6 - Dam Sediment Summary of Exceedances in SAC for Soil Sample Analysis

Sample ID Depth m BGL Analyte ISQG-Low ISQG-High Concentration

Detected Requires Remediation /

Management

Sediment

D3.South N/A Arsenic 20 (mg/kg) 70 (mg/kg) 37 (mg/kg) No


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Surface Water Contamination

Concentrations of all analytes in the surface water samples collected from the dams were below the SAC except for Faecal Coliforms and Escherichia coli (E.Coli). Concentrations were detected in all dams with the highest concentrations of Faecal Coliforms and E. Coli present in Dam 2 (D2), located adjacent Fill Wedge 1 (F1):

D2.South - 10 CFU/100ml for E.Coli; and D2.North - 320 CFU/100ml for coliforms, however only 7 CFU/100ml were confirmed as faecal coliforms.

It should be noted that surface water within the three (3) dams at 280 Garfield Road East, Riverstone is not utilised for potable drinking water or re-use on Site. It is advised that the concentrations of Faecal Coliforms and E.Coli are re-evaluated following the dewatering of the dams, as such, this information should be included in the Dewatering Management Plan (DMP). The DSI concluded that the Site was not suitable for the proposed development. ADE recommended that a Site specific RAP was prepared to address the identified contamination, and detail remediation requirements in order to be able to make the site suitable for the proposed land use.

3.4. ‘Waste Analysis and Classification Report’, ADE report no. STC-745-12410 / WAC1 / v1 draft, report dated 18th October 2017 (ADE 2017d)

The stockpile within Fill Wedge 1 (F1) was assessed in order to classify the materials in accordance with the NSW EPA’s Waste Classification Guidelines. Part 1: Classifying Waste (NSW EPA 2014) for off-site disposal. Eleven (11) soil samples were collected from the subject stockpile based on the sampling density prescribed in Victorian EPA Industrial Waste Resource Guidelines for Soil Sampling (2010), as referenced in Section 7.4.2 of the NEPM (2013).

The concentrations of Heavy Metals (As, Cd, Cr, Cu, Pb, Hg, Ni & Zn), TRH, BTEX, PAHs, PCBs, OCPs and OPPs in the soil samples collected from the subject stockpile met the NSW EPA criteria assigned for ‘Restricted Solid Waste (RSW)’; Toxicity Characteristic Leaching Potential (TCLP) TCLP analysis of the soils had not been undertaken. As such, ADE recommended that further assessment of the soils, by way of TCLP analysis be completed; The soil materials within the subject stockpile are considered to be classified as ‘non-putrescible’;

ACM was observed within the materials inspected. No asbestos was not detected within any of the soil samples collected; and

Currently the stockpiled soil materials are classified for off-site disposal in accordance with the NSW EPA (2014) as ‘Special Waste – Bonded Asbestos (as Restricted Solid Waste)’;

At the time of writing this RAP, the subject Waste Analysis and Classification Report is in draft form only and is yet to be finalised at the discretion of the client.


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3.5. ‘Waste Analysis and Classification Report’, ADE report no. STC-745-12410 / WAC2 / v1 draft, report dated 18th October 2017 (ADE 2017e)

The in-situ soil material within the eastern embankment of Dam 1 (D1) was analysed in accordance with the NSW EPA (2014) guidelines for off-site disposal. The material which exceeds the adopted SAC (HIL-D) is not suitable for the proposed development, and as such, has been classified for off-site disposal. Twelve (12) soil samples were collected from six (6) test pits based on the sampling density prescribed in the NSW EPA Contaminated Sites: Sampling Design Guidelines (NSW EPA 1995).

The concentrations of metals (As, Cd, Cr, Cu, Pb, Hg, Ni & Zn), TCLP (Lead and Benzo(a)pyrene), TRH, BTEX, PAHs, PCBs, OCPs and OPPs in the soil samples collected from the subject stockpile met the NSW EPA criteria assigned for ‘General Solid Waste (GSW)’; The soil materials within the subject area are considered to be classified as ‘non-putrescible’;

ACM was observed within the materials inspected. No asbestos was not detected within any of the soil samples collected; and

Currently the in situ soil materials are classified for off-site disposal in accordance with the NSW EPA (2014) as ‘Special Waste – Bonded Asbestos (as General Solid Waste)’;

At the time of writing this RAP, the subject Waste Analysis and Classification Report is in draft form only and is yet to be finalised at the discretion of the client.


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4. SITE IDENTIFICATION

4.1. Site Identification and Description

A summary of the Site details are given in Table 7. Table 7 - Summary of Site Identification Details.

4.2. Site Plans

The current site plan for 280 Garfield Road East and 259 Riverstone Road is shown in Figure 1.

Site Details Site Owner: Sunglow Development Management Pty Ltd Site Address: 280 Garfield Road East and 259 Riverstone Road, Riverstone NSW Title Identification: Lot 1, 2 and 3 of Deposited Plan (DP) 523552 Parish and County: Parish of Gidley, County of Blacktown

Geographic Coordinates:

South-western corner: -33.675606, 150.885267 North-western corner: -33.669224, 150.881096 North-eastern corner: -33.665908, 150.887407 South-eastern corner: -33.672264, 150.891904

Site / Investigation Area: Approximately 585,000 m2

Current Site Uses:

280 Garfield Road East: Low density industrial warehouse and manufacturing in the central southern section of the Site surrounded by car parks. The periphery of the Site is predominantly open fields with three (3) dams. 259 Riverstone Road: Residential building in the southern section of the Site with one (1) greenhouse shed and cut flower market gardens. The periphery of the Site is a mixture of open pasture and native bushland with artificial dams.


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Figure 1 - Current Site plan for 280 Garfield Road East and 259 Riverstone Road, Riverstone NSW (map adapted from Nearmap; accessed 04.10.2017).

4.3. Locality Maps and Key Site Observations

A locality map for 280 Garfield Road East and 259 Riverstone Road is shown in Figure 2.

KEYSite Boundary

Direction of Water Drainage

First Ponds Creek

AJ Bush and Sons Garfield Road East

Riverstone Road


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Figure 2 - Site Locality Map (maps adapted from Sixmaps; accessed 05.10.2017).


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5. SITE CONDITION AND SURROUNDING ENVIRONMENT

A summary of the Site condition and surrounding environment is given in Table 8 below. For a detailed site condition and surrounding environment see the associated PSI (ADE 2017b) and PSI/DSI (2017c) for the Site. Table 8 - Summary of Site Condition and Surrounding Environment.

Attribute Description Topography The Site has a gradual incline with a slope from the south east 49 m (Australian Height

Datum – AHD) towards the north-east 28 m AHD. The residence in the south-western section of the property is situated at 53 m AHD.

Surrounding Land Use & Site Boundary Condition

North - Garfield Road East followed by low density residential with market gardens East - “AJ Bush and Sons” meat processing facility South - Farmland and low density residential West - Low density residential with open pasture The Site is enclosed by a metal fence in ‘good’ condition, there are no signs of erosion on the Site boundary.

Visible Signs of Contamination

Bonded asbestos fibre cement fragments were observed on the soil surface in the following locations;

280 Garfield Road East, Dam 1 (D1), Eastern embankment, adjacent to storage racks, soil surface; and 259 Riverstone Road, centre of property, old building footprint, soil surface.

Visible Signs of Plant Stress

No visible indications of plant stress were observed during the course of the previous Site investigations.

Presence of drums, wastes and fill material

280 Garfield Road East, Riverstone – Fill Wedge 1 (F1) Blue “Mauser” plastic containers with unknown contents; Rusted “BP Bartran 68” drum containing a yellow liquid; “RX Super” drums containing a black liquid; Three (3) “Hi-tech” 44 gallon drums with unknown contents; and Car Battery.

280 Garfield Road East, Riverstone – Paddock 4 (P4) Aboveground Storage Tank (AST), no connection.

280 Garfield Road East, Riverstone – Dam 1 (D1) Approximately fifteen (15) bags of silica; Butoxyethanol (solvent) and metal in drums; and Asbestos cement sheeting debris.

280 Garfield Road East, Riverstone – Warehouse 1 (W1) Oil drums containing an unknown liquid; Barberton Iron & Steel” asbestos containing furnace; AST observed with “Caltex Engine Oil” with minor staining beneath; and High pressure gas storage vessel.

259 Riverstone Road, Riverstone Petrol refuelling station; Septic tank; and Freestanding brick chimney structure with asbestos fibre cement debris.


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Table 8 - Continued... Attribute Description

Odours / Staining

Hydrocarbon sheen was observed on the soil surface within Fill Wedge 1 (F1) and listed as AoC6. No significant hydrocarbon odour or staining was observed within any of the test pits, groundwater or surface water sample across the remainder of the Site (ADE 2017b, 2017c).

Conditions of Buildings and Roads

The warehouse and residential complex were observed to be in ‘good’ condition. Several derelict sheds in various states of disrepair were seen at 259 Riverstone Road, centre of property, old building footprint. These sheds were noted to contain lead containing paint and presumed PCB fluorescent light fittings.

Surface Water Quality

There were no indications of surface water contamination observed during the course of the previous investigations (ADE 2017b, 2017c). Discolouration of the dams within the Site was observed in historical aerial photographs indicating potential algal blooms and eutrophication.


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ADE Consulting Group Pty Ltd Unit 6 / 7 Millennium Court Silverwater, NSW 2128


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site: www.ADenvirotech.com.aue-mail [email protected]

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6. REVIEW OF SITE HISTORY

A summary of the site history is given in Table 9 below. For a detailed site history see the associated PSI (ADE 2017b) and PSI/DSI (2017c) for the Site. Table 9 - Summary of Site History.

Attribute DescriptionLand Use Zoning

The Site is currently zoned as R2 – Low Density Residential under the Sydney Region Growth Centres 2006 plan. The Planning Certificate under the Section 149 of the Environmental Planning and Assessment Act (EPA&A) 1979 provides the state and local environmental planning instruments which affect the Site. Details of information on the Site as contained in Clause 59(2) as amended in the CLM Act (1997) are listed below:

a) The land is not subject to a known contamination as per Section 149; b) The land is not subject to a management order within the meaning of the Act; c) The land is not subject to a voluntary management proposal within the meaning of

the Act; d) The land is not subject to an ongoing maintenance order; and e) The land is not subject to a Site audit statement within the meaning of the Act.

Current Land Use

280 Garfield Road East - A large warehouse facility situated along the southern boundary of the property with access from Garfield Rd East via a two (2) lane driveway. The warehouse is leased by three (3) companies; Flower Power, MaxiPak & Supreme Furniture and appears to be utilised as a storage and distribution centre for the companies. The warehouse is constructed primarily of brick and metal with a hardstand slab present throughout the building footprint. The warehouse sits atop a ridge and is the highest point of the land parcel, with the land falling to the north-east and south-west towards the two (2) large dams. A storage and lay down area is present on the eastern side of the warehouse. A walkover inspection indicated the area has been used for the storage of materials including hydraulic fluids, oils, shipping containers and general refuse associated with the adjacent warehouse. Stockpiles, dumped waste, surface asbestos, construction and demolition waste were observed throughout the area. It was noted that the storage yard was constructed on a large fill wedge placed on the eastern boundary of the warehouse. The remaining land has large portions of cleared paddocks. These appear to have been unused for extensive time frames. 259 Riverstone Road - The Site comprises a large two story residence situated along the southern boundary of the property with access to Riverstone Road via a one lane unpaved driveway. The residence is surrounded by maintained gardens and a large sunroom which houses an indoor pool. The grounds to the west of the residential complex are currently being used as grazing land for cattle. To the immediate north of the residential complex stands a large greenhouse, rose garden and shed which is currently being used to cultivate and house foliage, which is being propagated on the property. North of the greenhouse and rose garden is an old building footprint with a shed and associated rubble stockpiles. An easement runs parallel to the east of this old building footprint which separates the property into two sections. The area to the east of the easement is predominantly


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Current Land Use

uncleared land containing native vegetation while the area to the west is pasture. There are five (5) dams scattered across the property of varying sizes.

Historical Land Use

1955 - Site consists of a market garden / orchard with a house and driveway leading out to Garfield Road East. The majority of the Site is vegetated with a small dam in the eastern section of the Site. An easement transects the centre of the Site from north to south running parallel to an access path. LTO records from this period indicate an orchardist named Frederick Thomas Rumery owned the property during this period. 1975 - The market garden which surrounds the residence has been cleared and has been replaced with an open field. In the south of the Site, three (3) dams have been excavated. LTO records were unable to ascertain the land use from this period. 1991 - A commercial industrial warehouse facility has been constructed along with three (3) large dams adjacent to the warehouse. An access roadway has been constructed which runs from east to west and which services the warehouse. The south of the Site has undergone extensive agricultural development with the erection a residence, glass houses, large cooling shed and dam expansion. LTO records indicate that the northern section of the Site was owned by Egidio Nitopi and Christina Pirrello Nitopi, while, the southern section of the Site is owned by Raffaele Miscuso and Rosa Marna Miscuso utilising the land for rose and foliage cultivation. 2004 -The commercial / industrial warehouse has been extended along the eastern boundary. Additionally, an embankment has been created on the eastern boundary of the warehouse. Industrial / manufacturing activity is evident in the storage of shipping containers on the eastern and western sides of the warehouse. 2006 - A secondary addition of fill materials is evident in the reshaping of the dam to the west of the commercial / industrial warehouse which has given the eastern embankment of the dam a rounded shape. Storage of materials to the west and east of the commercial / industrial warehouse continues to increase with the eastern side of the warehouse being covered almost completely in wooden material. 2010 - The dam to the west of the commercial / industrial warehouse has been reshaped with the further addition of fill materials to the eastern embankment. Much of the refuse has been cleared from the east of the commercial / industrial warehouse and has been replaced by numerous sheds. There is apparent disturbance to the soil surface on the eastern edge of the eastern embankment. 2014 - The sheds on the eastern side of the warehouse have been removed and have been replaced by a large stockpile of wood fragments. Refuse continues to build up on the western side of the warehouse. In the south of the Site a number of the previously identified areas of cultivation are no longer in use. Two of the smaller sheds have been removed. LTO records indicate that the northern section of the Site was recently transferred to JAA Investment Nominees Pty Ltd.


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Proposed Land Use

The proposed construction works within the Site forms part of a larger development, which includes the subdivision of land for future residential land use. The larger development will include approximately 900 lots within the subject Site. The total development undertaken across the Site has total footprint of approximately 60 hectares (ha). The design will incorporate local roads and residential lots ranging between 260 m2 to approximately 800 m2 in size. Cut and fill activities will be required across much of the site during the preparation of the subdivision.

Inventory of Chemicals and Wastes

A Site search for schedule 11 (storage of hazardous chemicals) was undertaken for 280 Garfield Road East, Riverstone. The following hazardous chemicals were identified:

Forklift cylinders and liquefied natural gas listed on 18.11.2002; and Decanting cylinders listed on 24.10.2001.

All LTO records and historical photographs for 259 Riverstone Road, Riverstone indicate the property has been utilised only for residential / light agricultural purposes. In addition, the limited soil sampling survey for a range of analytes including TRH and volatiles undertaken by ADE indicate there has been no storage of hazardous chemicals on the property. As such, no search for schedule 11 was undertaken for 259 Riverstone Road, Riverstone.

Contaminated Land Register

A search of sites listed by the EPA under the CLM Act (1997) revealed that no records have been issued against the Site. No records of other contaminated sites that could have a potential impact on the Site are present on the properties in the area surrounding the site or the suburb of Riverstone.

Identified Aboveground and Underground Storage Tanks (ASTs/USTs)

The storage tanks were observed in the following locations during the Site walkover:

280 Garfield Road East, Paddock 4 (P4), southern section, adjacent to gazebo – This AST was not connected and does not appear to be currently in use and hence was treated as low risk. No surface staining or olfactory signs of contamination were observed, no elevated contaminants were detected in nearby soils; 280 Garfield Road East, Warehouse 1 (W1), centre, an UST was identified during plumbing works on the Site, the storage tank holds water and is not of concern. No surface staining or olfactory signs of contamination were observed; 259 Riverstone Road, southern section of property, 20 m north of glass house – An AST was identified as an old farm refuelling station. No surface staining or olfactory signs of contamination were observed, no elevated contaminants were detected in nearby soils; and 259 Riverstone Road, centre of property, old building footprint – an UST was identified and presumed to be an old septic tank. No surface staining or olfactory signs of contamination were observed.


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Sewer and Service Plans

Endeavour Energy - No assets affected. Jemena Gas West - No assets affected. National Broadband Network (NBN) - Dial Before You Dig (DBYD) identified an NBN pit running from the road access of 280 Garfield Road East to the middle of the western boundary of the property. Sydney Water – No assets affected. Telstra - A Telstra service pit was observed along Garfield Road East. This pit is attached to a line running from the pit to the north-western corner of the commercial / industrial warehouse.


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7. GEOLOGY AND HYDROGEOLOGY

7.1. Soil Stratigraphy

A summary of the soil stratigraphy for 280 Garfield Road East is shown in Table 11 and 259 Riverstone Road, Riverstone NSW is shown in Table 11. Full detailed soil descriptions and borehole logs are shown in previous Site investigations (ADE 2017a, 2017b & 2017c). Table 10 - Soil Specific Lithology for 280 Garfield Road East, Riverstone NSW.

Layer Material Description Depth of the Layer (m BGL)

Paddock 1 (P1), Paddock 2 (P2), Paddock 3 (P3) and Paddock 4 (P4)

Topsoil Silty SAND, fine / medium grained, dark brown, with humic material, moist. 0.0 - 0.5

Residual Silty CLAY, high plasticity, dark orange to dark red mottled light grey with shale and weathered shale fragments, moist. 0.5 - 3.5

Dam 1 (D1) – Eastern Section

Road Base Gravelly sand, coarse grained, dark grey with asphalt fragments, dry.

0.0 - 0.2

Fill

Sandy CLAY, coarse grained, low / medium plasticity, dark brown / dark grey with concrete asphalt, bricks, wood plastic, metals, rubber, cobbles, boulders, gravels and

localised ACM, moist.

0.2 - > 4.0

D1 – Northern, Western and Southern Sections

Road Base Gravelly sand, coarse grained, dark grey with asphalt fragments, dry. 0.0 - 0.2

Reworked Residual / Fill Silty CLAY, medium plasticity, dark brown with trace angular and sub-rounded medium / coarse gravels, moist. 0.2 - 3.5

Residual Silty CLAY, high plasticity, dark orange / dark red mottled light grey with shale and weathered shale fragments, moist. > 3.5

Fill Wedge 1 (F1) – Western Section


Topsoil / Fill Clayey SAND, medium plasticity, fine grained, light brown / light orange with trace gravels and foreign materials, moist. 0.0 - 0.5

Subsoil / Residual Clayey SAND, medium plasticity, fine grained, light orange with trace coarse gravels, moist. 0.5 - 1.0

F1 – Eastern Section


Fill Clayey SAND, medium plasticity, fine grained, light brown / light orange with trace gravels, moist. 0.2 - 1.0


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Table 10 - Continued... Layer Material Description Depth of the Layer (m BGL)

F1 – Eastern Section

Fill

Sandy CLAY, coarse grained, low / medium plasticity, dark brown / dark grey with concrete, asphalt, bricks, wood plastic, metals, rubber, cobbles, boulders, gravels and

localised ACM, moist.

1.0 - 3.7

Reworked Residual / Fill Silty CLAY, medium plasticity, dark orange / dark brown mottled light grey with trace gravels, moist. 3.7 - 4.5

Warehouse 1 (W1)

Concrete Concrete 0.0 - 0.1

Fill SAND, coarse grained, medium yellow with medium red / medium grey clay fragments, moist. 0.1 - 0.3

Reworked Residual / Fill Silty CLAY, medium plasticity, medium yellow / medium

brown with weathered shale fragments and mottled medium red / medium grey clay nodules, dry.

0.3 - 0.7

Residual Silty CLAY, medium plasticity, dark yellow / medium red with weathered shale fragments, dry. > 0.7

Table 11 - Soil Specific Lithology for 259 Riverstone Road, Riverstone NSW.

Layer Material Description Depth of the Layer (m BGL)

Topsoil Silty CLAY, medium plasticity, light brown with trace gravels, charcoal, roots and clay nodules, moist. 0.0 - 0.5

Subsoil Silty CLAY, medium / high plasticity, medium orange with

grey and red mottles with trace weathered shale fragments, moist.

0.5 - 1.0

7.2. Location and Extent of Imported and Locally Derived Fill

7.2.1. Fill Wedge 1 (F1) – Fill Type 1

Fill Type 1 - Generally fill materials containing elevated levels of asbestos exceeding the adopted SAC (HSL-A) were associated with a sandy CLAY, coarse grained, low / medium plasticity, dark brown / dark grey with concrete, asphalt, bricks, wood, plastic, metals, rubber, cobbles, boulders, gravels, moist which was isolated to the eastern portion Fill Wedge 1 (F1). This fill material was thickest on the eastern boundary of Fill Wedge 1 (F1) and is not present on the western section of Fill Wedge 1 (F1). This fill material was first identified in a historical aerial photograph from 2004 however importation of the fill material may have occurred earlier.

7.2.2.Fill Wedge 1 (F1) – Fill Type 2 Fill within the western portion of Fill Wedge 1 (F1) generally consisted of silty CLAY, medium plasticity, orange / brown mottled light grey with trace gravels, moist. This material appears to have been imported during the construction of the warehouse which occurred anywhere between 1975 and 1990. It is important to note that this fill material appeared to be reworked virgin material and did not contain ‘Bonded’ ACM or foreign


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materials. Virgin materials were observed below the imported fill and consisted of a Silty CLAY, high plasticity, dark orange / dark red mottled light grey with shale and weathered shale fragments, moist. This material did not contain ACM. Fill Type 2 was observed to extend beneath Fill Type 1 in the central to eastern section of F1 and increased in depth as the profile moved towards the east (towards the dam).

7.2.3.Dam 1 (D1) – Fill Type 3 Generally fill materials containing elevated levels of ‘bonded’ ACM exceeding the adopted SAC (HIL-A) were associated with a sandy CLAY, coarse sand, low / medium plasticity, dark brown / dark grey with concrete, asphalt, bricks, wood, plastic, metals, rubber, cobbles, boulders, gravels and localised ACM, moist. This fill material was isolated to the eastern embankment of Dam 1 (D1). The eastern embankment of Dam 1 (D1) changes from an angular to rounded shape in an aerial photograph from 2006 suggesting Fill Type 3 was imported during this period. There is a similarity in colour, foreign materials and texture between Fill Type 3 and Fill Type 1 which both contain elevated levels of ‘bonded’ ACM exceeding the adopted SAC (HIL-A);

7.2.4.Dam 1 (D1) – Fill Type 4 Fill within the northern, southern and western embankments of Dam 1 (D1) generally consisted of silty CLAY, medium plasticity, medium brown with trace angular and sub-rounded medium / coarse gravels, moist. This material appears to have been imported during the construction of the warehouse and dam which occurred anywhere between 1975 and 1990. It is important to note that this fill material appeared to be reworked virgin material and did not contain ‘Bonded ACM’ or foreign materials. Virgin materials were observed below the imported fill and consisted of a Silty CLAY, high plasticity, dark orange / dark red mottled light grey with shale and weathered shale fragments, moist. The virgin material did not contain ACM.


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7.3. Regional Setting

A summary of the hydrogeological and geological setting for the Site is shown in Table 12. Detailed descriptions for the hydrogeology and geology are given in previous Site investigations (ADE 2017a, 2017c). Table 12 - Regional Setting for Site.

Attribute Description Local Geology and Soil

The Site is located on the Blacktown Soil Landscape (bt) as indicated on the NSW Office of Environment and Heritage eSpade GIS tool. The soils of the Blacktown Soil Landscape (bt) are underlain by Wianamatta group Ashfield Shale and Bringelly Shale formations. The Ashfield shale is comprised of laminate and dark grey shale. Bringelly shale consists of shale, calcareous claystone, laminate and fine to medium grained lithic-quartz stone. Soils are shallow to moderately deep (< 100cm) with variability across upper slopes and drainage gullies. The topsoil (A1 Horizon) consists of a friable dark brown loam, with moderately to strongly pedal structure, apedal single-grained structure and porous sandy fabric. The pH ranges from strongly acid (pH 4.0) to slightly acid (pH 6.0). Beneath this layer occurs the B Horizon consisting of hard-setting clay loam. The pH ranges between strongly acid (pH 4.0) to slightly acid (pH 6.5). In conjunction with the B Horizon, a strongly pedal brown to reddish brown light clay occurs. The pH varies from strongly acid (pH 4.5) to moderately acid (pH 6.5). Frequent red yellow or grey mottles occur in addition to gravel sized shale fragments. Roots and charcoal fragments are rare. A B3 or C horizon is present as light grey plastic mottled clay, usually occurring as deep subsoil above shale bedrock. Yellow and grey mottles are common with pH ranging from strongly acid (pH 4.0) to moderately acid (pH 5.5). Virgin soil materials observed during investigative works were consistent with the soil landscape map for the area.

Site Drainage & Hydrogeology

The underlying soils in the area generally consisted of silty clay underlain by weathered shale (refer to Table 10 and Table 11 which impedes downward movement of water and will therefore be expected to have a moderate / low rate of water transmission and a moderate / low capacity to hold water. Localised surface water bodies such as ponds and dams were observed in aerial images during the Site walkover, indicating a high water table in the area. The dams situated on the north-eastern and south-western flanks of the warehouse have been constructed with impervious clay / shale containing walls. ADE considers it unlikely that groundwater is interacting with the water contained within the two (2) dams, further visual assessment may be required once the dams have been dewatered. Any groundwater is expected to


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Site Drainage & Hydrogeology

take the course of drainage channels which drain into First Ponds Creek and the Killarney Chain of Ponds. Surface water collecting on fill materials or paved areas will travel predominately via overland flow and secondarily via seepage into the local dams. A search for registered groundwater wells within a 500 m radius of the Site was undertaken by ADE via the NSW Office of Water (Allwaterdata.water.nsw.gov.au).

Hydrogeology The following four (4) registered bore wells were recorded:

GW112594; GW112593; GW112595; and GW112596.

Information obtained from the groundwater bores suggests a standing water level of approximately 2.5 m to the top of casing (TOC) and salinity between 649 and 2820 mg/L.

No other information for groundwater quality was available from the groundwater bores within 500 m radius of the Site.

Acid Sulphate Soil Risk

A review of the Australian Soil Resource Information System (ASRIS) interactive map was undertaken to determine the potential for Acid Sulfate Soil (ASS) at the Site. The source Site was identified as a ‘no known occurrence’ area in regards to ASS risk. No observations (staining, odour) indicative of ASS were noted during the field works.

Depth to Groundwater

Groundwater was encountered during the course of an investigation at 280 Garfield Road East as detailed in ADE (2017c). The standing groundwater level was found at approximately 3.0 m BGL atop a layer of low permeability shale.

Nearest Surface Water Feature

First Ponds Creek (100 m west of Site); Residential / Agricultural Dams (5 found on Site and several on neighbouring properties); Killarney Chain of Ponds (250 m south east of Site); and Eastern Creek (1,500 m east of Site).


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8. REMEDIATON ASSESSMENT CRITERIA

The proposed development at the Site is low density residential. The Remediation Acceptance Criteria (RAC) has been selected in accordance with the National Environment Protection (Assessment of Site Contamination) Measure 1999, 2013 Amendment’. Given the proposed development at the Site (refer to Section 1.2), the following investigation and screening levels have been selected in order to successfully remediate and validate the Site.

8.1. Health Investigation Levels (HILs)

The NEPM (2013) guidelines stipulate four generic land use settings for assessment used in the first stage (Tier 1 or ‘screening’) of potential risks to human health from a broad range of metals and organic substances. The HILs are applicable for assessing human health risk via all relevant pathways of exposure for the following generic land use settings:

HIL A - Residential with garden/accessible soil (home grown produce <10% fruit and vegetable intake, (no poultry), also includes children’s day care centres, preschools and primary schools; HIL B - Residential with minimal opportunities for soil access includes dwellings with fully and permanently paved yard space such as high-rise buildings and flats;

HIL C - Public open space such as parks, playgrounds, playing fields (e.g. ovals), secondary schools and footpaths. It does not include undeveloped public open space (such as urban bushland and reserves) which should be subject to a site-specific assessment where appropriate; and

HIL D - Commercial / industrial such as shops, offices, factories and industrial sites.

Based on the information provided to ADE outlining the scope of the proposed development i.e. residential properties, HIL A has been adopted as the Tier 1 screening criteria. ADE understands there is the potential for the re-use of fill materials beneath the facilitating roads and streets, as such HIL D has been considered specifically for these areas. A Site Plan identifying the locations for re-use of HIL A and HIL D soil materials can be referred to in Appendix II – Development Plans.

8.2. Health Screening Levels (HSLs)

HSLs have been developed for selected petroleum compounds and fractions and are applicable to assessing human health risk via the inhalation and direct contact pathways. The HSLs depend on specific soil physicochemical properties, land use scenarios, and the characteristics of building structures. ADE has adopted the NEPM 2013 Tier 1 screening criteria for BTEX, Naphthalene, TRH fractions C6-C10 and C10-C16 for Vapour Intrusion. Additional Tier 1 HSL screening criteria as per Friebel and Nadebaum’s Health Screening levels for petroleum hydrocarbons in soil and groundwater, Part 2: Application Document, Technical report No. 10 (2011) have also been adopted to include Vapour Risk to Intrusive Maintenance Workers (Shallow Trench 0.0 to <2.0 m), and HSL levels for direct human contact, outlined in Table 13 & Table 14.


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8.3. Management Limits

‘Petroleum hydrocarbon management limits (‘management limits’) are a set of assessment criteria outlined in NEPM 2013 applicable to petroleum hydrocarbon compounds which aim to avoid or minimise the potential effects of:

Formation of observable light non-aqueous phase liquids (LNAPL); Fire and explosive hazards; and Effects on buried infrastructure e.g. penetration of, or damage to, in-ground services by hydrocarbons.

The Management Limits provide Tier 1 screening levels following evaluation of human health and ecological risks and risks to groundwater resources, and are considered relevant for operating Sites where significant sub-surface leakage of petroleum compounds has occurred and when decommissioning industrial and commercial Sites. The adopted Management Limits from Table 1B (7), Schedule B1 of NEPM (2013) are shown in Table 13 & Table 14 on the following pages, please refer to Appendix III – Notes to Tables.


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Table 13 - Remediation Assessment Criteria – HIL A / HSL A for soil contamination, mg/kg (unless otherwise specified).

Analyte

Health Investigation Levels (HILs)1

Health Screening Levels (HSLs) Management Limits

HIL A (mg/kg)

Vapour Intrusion

(0 m to <1 m) - HSL A

1,3, 6

(mg/kg)

Vapour Intrusion

(1m to <2m) - HSL A

1, 3, 6

(mg/kg)

Vapour Intrusion

(2m to <4m) - HSL A

1, 3, 6

(mg/kg)

Vapour Intrusion (4m+)

- HSL A1,3, 6

(mg/kg)

HSL Intrusive Maintenance Worker

(Shallow Trench - SILT)3

(mg/kg)

Direct Contact - HSL A (mg/kg)

Residential, parkland and public open space

Arsenic (total) 100

-

-

-

-

-

-

-

Cadmium 20 - - - - - - - Chromium (Total) 100 - - - - - - - Copper 6,000 - - - - - - - Lead 300 - - - - - - - Mercury (inorganic) 40 - - - - - - - Nickel 400 - - - - - - - Zinc 7,400 - - - - - - - Carcinogenic PAHs (as BaP TEQ)2 3

- -

-

-

-

-

-

Polycyclic aromatic hydrocarbons (PAHs)

300 -

-

-

-

-

-

-

PCBs (Total) 1 - - - - - - - DDT+DDE+DDD 240 - - - - - - - Aldrin and Dieldrin 6 - - - - - - - Chlordane 50 - - - - - - - Endosulfan 270 - - - - - - - Endrin 10 - - - - - - - Heptachlor 6 - - - - - - - Hexachlorobenzene 10 - - - - - - - Methoxychlor 300 - - - - - - - Chlorpyrifos 160 - - - - - - - Benzene - 0.5 0.5 0.5 0.5 77 100 - Toluene - 160 220 310 540 12,000 14,000 - Ethyl Benzene - 55 NL NL NL 85,000 4,500 - Xylene - 40 60 95 170 130,000 12,000 - Naphthalene - 3 NL NL NL 29,000 1,400 - TRH: C6 – C10 (F1) - 455 70 110 200 82,000 4,400 700 TRH: C10-C16 (F2) - 1106 240 440 NL 62,000 3,300 1,000 TRH: C16- C34 (F3) - - - - - 85,000 4,500 2,500 TRH: C34 – C40 (F4) - - - - - 12,000 6,300 10,000


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Table 14 - Remediation Assessment Criteria – HIL D / HSL D for soil contamination, mg/kg (unless otherwise specified).

Analyte

Health Investigation Levels (HILs)1

Health Screening Levels (HSLs) Management

Limits

HIL D (mg/kg)

Vapour Intrusion

(0 m to <1 m) - HSL D

1,3, 6

(mg/kg)

Vapour Intrusion

(1m to <2m) - HSL D

1, 3, 6

(mg/kg)

Vapour Intrusion

(2m to <4m) - HSL D

1, 3, 6

(mg/kg)

Vapour Intrusion (4m+)

- HSL D1,3, 6

(mg/kg)

HSL Intrusive Maintenance Worker

(Shallow Trench)3

(mg/kg)

Direct Contact - HSL D (mg/kg)

Commercial and Industrial

Arsenic (total)

3,000

-

-

-

-

-

-

-

Cadmium 900 - - - - - - - Chromium (Total) 3600 - - - - - - - Copper 240,000 - - - - - - - Lead 1,500 - - - - - - - Mercury (inorganic) 730 - - - - - - - Nickel 6,000 - - - - - - - Zinc 400,000 - - - - - - - Carcinogenic PAHs (as BaP TEQ)2

40

Polycyclic aromatic hydrocarbons (PAHs)

4,000

-

-

-

-

-

-

-

PCBs (Total) 7 - - - - - - - DDT+DDE+DDD 3,600 - - - - - - - Aldrin and Dieldrin 45 - - - - - - - Chlordane 530 - - - - - - - Endosulfan 2,000 - - - - - - - Endrin 100 - - - - - - - Heptachlor 50 - - - - - - - Hexachlorobenzene 80 - - - - - - - Methoxychlor 2,500 - - - - - - - Chlorpyrifos 2,000 - - - - - - - Benzene - 4 6 9 20 77 430 - Toluene - NL NL NL NL 12,000 99,000 - Ethyl Benzene - NL NL NL NL 85,000 27,000 - Xylene - NL NL NL NL 130,000 81,000 - Naphthalene - NL NL NL NL 29,000 11,000 - TRH: C6 – C10 (F1) - 310 480 NL NL 82,000 26,000 700 TRH: C10-C16 (F2) - NL NL NL NL 62,000 20,000 1,000 TRH: C16- C34 (F3) - - - - - 85,000 27,000 3,500 TRH: C34 – C40 (F4) - - - - - 12,000 38,000 10,000


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8.4. Asbestos

The above highlighted criterion (HIL-A and HSL-A) was adopted based on information provided to ADE by the client indicating the Site is to be redeveloped for low density residential housing. Additionally, ADE has been advised that there is the possibility that only ACM (<HSL-D) soil materials could be placed under roads for the proposed development. As such, the HSL-A and HSL-D will be considered for the presence of asbestos within the soil materials as shown in Table 15. The criteria specified in the following publications were used for the site assessment:

Assessment, Remediation and Management of Asbestos-Contaminated Sites in Western Australia, 2009 (DoH 2009); and National Environment Protection (Assessment of Site Contamination) Measure (1999), 2013 Amendment.

Table 16 - Adopted RAC as detailed in NEPM (2013).

Analyte Health Screening Levels (HSLs)

HSL-A HSL-D

Bonded ACM 0.01% 0.05%

FA and AF 0.001%

All Forms of Asbestos No Visible Asbestos For Surface Soil

The Site will be considered successfully remediated if, and, when the concentrations of any CoPC are below the adopted investigation and screening levels provided in Tables 13, 14 & 15.

8.5. Groundwater Investigation Levels

Groundwater was observed to contain marginally elevated concentrations of Nickel and Zinc, as detailed in the PSI/DSI for the Site (ADE 2017c). Interaction of the standing groundwater table (approximately 3.0 m BGL) with the residual natural soil materials accounted for the Nickel and Zinc exceedances. The client is not expected to extract groundwater for beneficial use during the construction or operational phase of the proposed development. If groundwater is expected to be encountered, or extracted for any purpose such as dewatering during any stage of the construction or remediation phase, further sampling may be required in addition to a Site specific groundwater management plan.

8.6. Scope of Ecological Assessment

NEPM 2013 outlines that a pragmatic risk-based approach should be taken in applying Ecological Investigation Levels (EILs) and Ecological Screening Levels (ESLs) in residential land use settings. ADE has been advised by the


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client that the proposed development will involve the construction of 939 lots with associated low density housing and roads. Final design is not yet complete, however the majority of the Site will undergo cut and fill activities as per the drawings (C1011, C1015, C1041-C1051) in Appendix II – Development Plans. All ACM containing soils suitable for re-use within the Site will be buried and encapsulated beneath earmarked roads for the proposed redevelopment. Taking this into consideration, further assessment of risk to terrestrial ecosystems by adopting the EILs and ESLs is required once the final design of the Site has been approved. Necessary changes should be detailed and adhered to within this RAP.

8.7. Waste Analysis and Classification

For waste classification purposes, soil materials will be assessed against:

NSW EPA publication Waste Classification Guidelines Part One: Classifying Waste (November 2014).

Waste classification would take into account all previous “in situ” testing results. The waste classification criteria for the contaminants of concern are provided in the following Table 16. Table 17 - Leachable Concentrations (TCLP) and Specific Contaminant Concentrations (SCC) Values for Classifying Waste by Chemical Assessment.

Contaminant

Maximum values for leachable for Leachable Concentration and Specific Contaminant Concentration when Used Together

General Solid Waste1 Restricted Solid Waste TCLP12 (mg/L) SCC1 (mg/kg) TCLP2 (mg/L) SCC2 (mg/kg)

Arsenic 5.02 500 20 2000 Benzene 0.52 18 2 72 Benzo(a)pyrene3 0.044 10 0.16 23 Cadmium 1.02 100 4 400 Chromium (IV)5 52 1900 20 7600 Ethyl Benzene 306 1080 120 4320 Lead 52 1500 20 6000 Mercury 0.22 50 0.8 200 Nickel 26 1050 8 4200 C6-C9 Petroleum Hydrocarbons NA7 650 NA7 2600 C10-C36 Petroleum Hydrocarbons NA7 10000 NA7 40000 Phenol8 14.48 518 57.6 2073 Polychlorinated Biphenyls NA7 <50 NA7 <50 Polycyclic Aromatic Hydrocarbons (total)

NA7 200 NA7 800

Toluene 14.48 518 57.6 2073 Xylenes (total) 509 1800 200 7200

Notes to Table: 1. Values are the same for both general solid waste (putrescible) and general solid waste (non-putrescible) 2. See Hazardous Waste Management System: Identification and Listing of Hazardous Waste – Toxicity Characteristics Revisions, Final Rule (USEPA 1990) for TCLP levels 3. There may be a need for the laboratory to concentrate the sample to achieve the TCLP limit value for benzo(a)pyrene with confidence 5. These limits apply to chromium in the +6 oxidation state only 6. Calculated from Australian Drinking Water Guidelines (NHMRC 1994) 7. No TCLP Analysis is required 8. Proposed level for phenol and toluene in Management System: Identification and Listing of Hazardous Waste – Toxicity Characteristics Revisions, Final Rule (USEPA 1990)

Should any Virgin Excavated Natural Materials (VENM) be required to be removed offsite for beneficial re-use/disposal, it would be assessed against published background concentrations:


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NEPM (1999). National Environmental Protection (Assessment of Site Contamination) Measure Schedule B(1) Guidelines on the Investigation Levels for Soil and Groundwater, Background Ranges.

The background concentrations for the analytes of concern are provided in Table 17 below. Table 18 - Published Australian Background Soil Concentrations.

Contaminant ANZECC 1992 (mg/kg) NEPC 1999 (mg/kg) Arsenic 0.2-30 1-50 Cadmium 0.04-2 1 Chromium 0.5-110 5-1000 Copper 1-190 2-100 Lead <2-200 2-200 Mercury 0.001-0.1 0.03 Nickel 2-400 5-500 Zinc 2-180 10-300 PAHs 0.95-5 ND

Organic analytes (TPH, BTEX, OCP, PCB and phenols) would be assessed against the laboratory reporting limit. In other words, for organic analytes, VENM analysis results must be below the laboratory PQL (practical quantification limit) to be classified as VENM.

8.8. Aesthetics

NEPM 2013 requires that aesthetic quality of accessible soils be considered even if analytical testing demonstrates that concentrations of COPCs are within the SAC. It should be noted that there are no quantifiable guidelines in determining if soils are appropriately aesthetic, however, NEPM (2013) does indicate that professional judgement with regard to quantity, type and distribution of foreign materials and/or odours in relation to the specific land use should be employed. The following scenarios including, but not limited to would trigger further aesthetic assessment:

Hydrocarbon sheen on surface water; Anthropogenic soil staining; and Odorous soils i.e. petroleum hydrocarbon odours or hydrogen sulphide in soil.

8.9. Statistical Analysis

A contaminant concentration in soil will be deemed acceptable if:

The maximum concentration of all samples meet the specified acceptance criteria; or The 95% UCL average concentration of each contaminant is below the acceptance criteria; and No individual exceedance is greater than 2.5 times the acceptance criteria.

If a location is found to have more than two and half times (2.5x) a contaminant’s acceptable limit, then it will be classified as a “hot-spot”, requiring further assessment, remediation, removal or management.


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If the calculated 95% UCL of the arithmetic average concentration of the contaminant is above their acceptance criteria, then the soil will be considered contaminated, requiring further assessment, remediation, removal or management. Statistical analysis, however, is not considered suitable for asbestos contamination.

8.10. Duty to Report Contamination

During the course of the environmental investigations at the Site, ADE concluded that there was no basis to consider a Duty to Report Contamination regarding asbestos in, or on, soil. However, if during the remediation works any additional sources of contamination are discovered an assessment of the analytical results against the SAC shall be undertaken. In accordance with the Guidelines on the Duty to Report Contamination under the CLM Act (1997), the following shall provide an assessment of the client’s responsibility to notify the NSW EPA of additional contamination that may be encountered.

8.10.1. On-site Soil Contamination For the purposes of section 60(3)(b) of the CLM Act, notification of contamination in, or on, soil on the land is required where:

The 95 % upper confidence limit on the arithmetic average concentration of a contaminant in or on soil is equal to or above the Health Investigation Level and/or Health Screening Level for that contaminant for the current or approved use of the respective on-site land, as specified in Section 6, Schedule B1 of the National Environment Protection (Assessment of Site Contamination) Measure 1999 (NEPC 2013) OR The concentration of a contaminant in an individual soil sample is equal to or more than 250% of the Health Investigation Level and/or Health Screening Level for that contaminant for the current or approved use of the respective on-site land, as specified in Section 6, Schedule B1 of the National Environment Protection (Assessment of Site Contamination) Measure 1999 (NEPC 2013)

AND

A person has been or foreseeably will be exposed to the contaminant or a by-product of the contaminant.

8.10.2. Asbestos, in, or on, Soil For the purposes of section 60(3)(b) of the CLM Act, notification of asbestos contamination is required where:

Friable asbestos is present in or on soil on the land


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AND The level of asbestos (% weight for weight) in an individual soil sample is equal to or above the health screening level of friable asbestos in soil (0.001%) specified in Section 4.8, Schedule B1 of the National Environment Protection (Assessment of Site Contamination) Measure 1999 (NEPC 2013) AND A person has been, or foreseeably will be, exposed to elevated levels of asbestos fibres by breathing them into their lungs.

No friable ACM was observed or detected within any of the soil samples collected from Site during the previous investigations (ADE 2017b, 2017c). However, ACM was observed and detected within the soil materials. ADE has not been advised by the client of any receptors that have been, or foreseeably will be, exposed to elevated levels of asbestos fibres. Taking this into consideration, no Duty to Report Contamination is required regarding asbestos in, or on, soil.


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9. SITE CHARACERISATION

Based on the conclusions made in ADE (2017c), Table 18 below presents the sources of CoPC, their pathways and receptors. Table 19 - Potential Sources, Locations and Types of Contaminants.

Potential Source of Contamination Location Migration Pathway Potential

Risk CoPC

Demolition of buildings (onsite)

Beneath Warehouse 1

Downward migration and leaching of contaminants via infiltration of rain water through soil; Lateral migration via groundwater to surface waters and off-Site groundwater; Overland flow of surface water to off-Site soils and surface waters; and Dispersion airborne particulates due to wind.

Moderate Asbestos; Heavy Metals; PCBs; PAH; TRH; and BTEX.

Commercial industrial warehouse onsite

Footprint or warehouse and immediate surrounds


Moderate Asbestos; Heavy Metals; PCBs; PAH; VOCs; TRH; and BTEX.

Stockpiled waste materials (onsite)

Construction and demolition wastes observed across the Fill Wedge 1 (F1) & D1


Moderate Asbestos; Heavy Metals; PCBs; PAH; TRH; VOCs; and BTEX.

Use of Imported fill materials (onsite)

Dam 1 and Fill Wedge 1 (F1)


Moderate - High

Asbestos; Heavy Metals; PCBs; PAHs; TRH; BTEX; VOCs; and OPPs and OCPs.

Historical agricultural usage (onsite)

In-situ soil materials throughout the Site

Downward migration and leaching of contaminants via infiltration of rain water through soil; Lateral migration via groundwater to surface waters and off-Site groundwater; and Overland flow of surface water to off-Site soils and surface waters.

Low - Moderate

Heavy Metals; TRH; and OPPs and OCPs.


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Table 18 - Continued... Potential Source

of Contamination Location Migration Pathway Potential Risk CoPC

Surrounding land uses (offsite)

Meat processing plant to east of the Site

Lateral migration of contamination from offsite sources through infiltration via groundwater or surface water runoff.

Low Heavy Metals; TRH; BTEX; TRH; and VOCs.

Primary transport mechanisms for the migration of potential contaminants onto the Site or off the Site include:

Airborne particulates due to wind turbulence events; Surface water runoff and leaching into groundwater; Downward migration and leaching via infiltration of rain water into the soils and groundwater; Lateral migration via groundwater to surface waters; and Volatisation of soil / groundwater contaminants and inhalation.

Figure 3 on the following page presents the information from above, the sources of COPC, their pathways and receptors.


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Primary Sources Secondary Sources Transport Mechanisms Exposure Pathways Exposed Population Characterisation

Figure 3 - Conceptual Site Model for Site.

Historical and current use of the Site for agricultural purposes

Impacted surface soils (<0.5 m BGL)

Impacted subsurface soils (>0.5 m BGL)

Impacted groundwater

Use of imported fill and stockpiled materials

Demolition of buildings on-site

Leaching and infiltration into soils and groundwater

Volatisation and atmospheric dispersion

Stormwater/surface water transport

Soil and Groundwater Ingestion/ absorption, dermal contact

Inhalation of vapours and fibres

Future users of the Site on site/off site Construction workers and site visitors during excavation works First Ponds Creek

Local Groundwater

Local surface water including five (5) dams on Site

Local fauna and flora that may inhabit or migrate through the Site

Hydraulically down gradient groundwater bores that may be used by humans or groundwater used in agriculture or

kl d

Commercial industrial warehouse onsite

Stockpiled waste materials stored on site

Transport of contaminants by mechanical disturbance (eg. earthworks)


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10. REMEDIAL ACTION PLAN

The main objectives of the Site remediation works are to render the Site suitable for the proposed future land use (low density residential properties) and to ensure that the works will not pose unacceptable risks to human health and / or to the environment.

10.1. Extent of Remediation Required

10.1.1. Known Extent

Former environmental investigations undertaken have indicated the presence of CoPC within the soils at the Site. The CoPC identified through intrusive soil sampling were Lead and ‘Bonded’ ACM (refer to Appendix I – Areas of Concern). The RAP specifically targets the Lead and ACM hotspots within the soil materials. In addition, 44 gallon drums, mauser containers, stockpiled fill materials, potential impacted soils from septic tank / ASTs and surficial ACM were observed across the Site and will be addressed in this RAP.

10.1.2. Unknown Extent The defined extent of remedial works will not be ascertained until remediation works begin. The following aspects of the remediation works can be considered unknown:

Lateral extent of the Lead and ACM hotspots; and ACM contamination may be present at greater depths than the maximum investigation test pit depth; Subsurface ACM contamination at 259 Riverstone Road, Riverstone where soil sampling was not undertaken due to the limited nature of the investigation; Extent of soil contamination (if any) underlying the 44 gallon drums / mauser containers; and Vertical and lateral extent of potential soil contamination associated with the ASTs / USTs (Septic Tank) identified on Site.

10.2. Remediation Options

In assessing and determining the optimal remedial options available to the Site, the following factors have been considered:

The source, types and level of contamination present; The vertical and lateral extent of soil contamination; The leachate potential of contaminants; Permeability and heterogeneity of the soil and hydrology of the Site; The future land use proposed for the remediation area; The client’s preferred method of remedation; Proven remediation methods and technologies that are available; Time, budgetary, engineering, environmental constraints; and Regulatory requirements.


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A number of remedial options were reviewed. The suitability of the remedial options was examined with respect to the requirements of the proposed development. Typical remedial options that may achieve the remedial objectives are identified as:

1. On-site treatment of the soil so that the contaminant is either destroyed or the associated hazard is reduced to an acceptable level;

2. Off-site treatment of excavated soil so that the contaminant is either destroyed or the associated hazard is reduced to an acceptable level, after which the soil is returned to the Site;

3. Removal of contaminated soil to an approved site or facility, followed where necessary by replacement with clean fill; and

4. Consolidation and isolation of the soil on-site by containment within a properly designed barrier. The previous are the preferred order for the Site remediation and management as stated in the NSW DECCW (2006) ‘Guidelines for the NSW Site Auditor Scheme’.

10.3. Remediation Rationale

After considering the type of contamination, proposed land use, construction design, development constraints and costs, the following conclusions have been made when reviewing the remediation options: Remediation Option 1 - On-site treatment of the soil so that the contaminant is either destroyed or associated hazard is reduced to an acceptable level:

Asbestos cannot be destroyed, it can only be removed and relocated; In-situ remediation of Lead is both difficult and expensive; Disposal of some contaminated soils may still be required; and The excavation of the affected materials is to a depth of 4.5 m BGL.

Taking the above information into consideration, ADE considers Remediation Option 1 is not suitable for the Site. Remediation Option 2 - Off-site treatment of excavated soil so that the contaminant is either destroyed or associated hazard is reduced to an acceptable level, after which the soil is returned to the Site:

Asbestos cannot be destroyed, it can only be removed and relocated; The removal of Lead impacted soils off site, remediating and returning to Site would exhaust allowable time and financial resources; and The excavation of the affected materials is to a maximum depth of 4.5 m BGL.

Taking the above information into consideration, ADE considers Remediation Option 2 is not suitable for the Site. Remediation Option 3 - Removal of contaminated soil to an approved site or facility, followed where necessary by replacement with clean fill:


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The cost of the removal of Lead and ACM impacted soils (above the adopted SAC) to an approved site or facility is both practicable and cost effective in comparison with other remediation options; Simple and straight forward process; Short time frame; and The complete removal of Lead impacted soils and ACM from the Site would eliminate any risk to human health.

Taking the above information into consideration, ADE considers Remediation Option 3 is suitable for the Site. Remediation Option 4 - Consolidation and isolation of the soil on-site by containment within a properly designed barrier:

The cost of consolidation and isolation of the Lead and ACM contaminated soil within the Site is both practicable (filling on site required) and cost effective (avoid disposal costs); and ACM contaminated soils would remain on Site (below SAC); May be subject to Council approval; Owner of contaminated soils remains liable; Additional investigations required prior to on-site burial; It must also be noted that ADE has been advised by the client that utilisation of an engineered cell to 'cap and contain' materials, with an associated Long Term Environmental Management Plan (LT-EMP) is not desired; and Notation on Section 149 Certificate and the Site’s Asbestos Register may be required.

Taking the above information into consideration, ADE considers a combination of both Remediation Options 3 and 4 suitable for the Site.

10.4. Recommended Remediation Option

The Site in its current condition may pose a long term risk to human health and / or the environment if the contamination is left unmanaged / unremediated. Based on the above considerations, the preferred remediation options are for offsite disposal of contaminated soil to a licensed facility and consolidate / isolate contaminated soils via onsite containment within a properly designed barrier.

10.4.1. Off Site Disposal Previously identified soil materials with Lead concentrations above the RAC (greater 2.5 X HIL A) and ACM soils above the RAC (HSL D) require hotspot removal to the nearest vertical and lateral ‘clean’ points. All soils within this category require off site disposal to a licensed waste facility with a relevant Waste Analysis and Classification Report.

10.4.2. Re-Use on Site Soil materials with ACM concentrations below the RAC (<HIL D / HSL D) require relocation from the source to the encapsulation areas below the road footprints shown in Appendix II – Development Plans. The capping layer with consist of the road subgrade and asphalt surface layer. As the concentration of ACM within these


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soils is below the land-use criteria (i.e. HSL D), and as the materials are being placed below are road way with no accessible ACM on the surface, an EMP and notation on the Land Title is not deemed necessary as per NEPM 2013.

10.5. Remediation Works Plan

The remediation strategy proposed will involve excavation and removal of contaminated soils from the AoC with eventual capping of ACM soils (<HSL D). These are listed below in Table 19. This section of the RAP provides the principle strategy for the proposed remediation works at the Site. Table 20 - Location and description of AoC addressed in the RAP.

Area of Concern Type / Description of Contamination Location

AoC1 Potential Hydrocarbon Impacted Soil Materials and ASTs Warehouse (1), Paddock (4), 259 Riverstone Road

AoC2 44 Gallon Drums / Mauser Containers Fill Wedge (1), Dam (1), Warehouse (1), 259 Riverstone Road

AoC3 Bonded ACM Soil Surface Dam (1), 259 Riverstone Road

AoC4 Stockpiled Fill Fill Wedge (1)

AoC5 Underground Septic Tank 259 Riverstone Road AoC6 Lead Hotspot Fill Wedge (1) AoC7 Bonded ACM Soils (>HSL-D) Dam (1) AoC8 Bonded ACM Soils (<HSL-D) Fill Wedge (1), Dam (1)

10.6. Roles and Responsibilities

The roles and responsibilities of the various parties involved in the remediation and subsequent validation of the Site are outlined below: Table 21 - Roles and Responsibilities for the Remediation Works.

Roles Responsibility Project Manager Responsible for overall direction of civil and environmental works

associated with the remediation works. Remediation Contractor Responsible for undertaking the remedial works (civil and earthworks)

and for procuring and complying with all the relevant approvals such as those required to undertake the proposed remediation works.

Environmental Consultant Responsible for providing technical guidance to the remediation contractor in order to successfully implement the requirements set out in the RAP. Supervision of remediation works, collection and analysis of validation samples and advising client of appropriate actions necessary based on observations, sampling and analysis. Responsible for providing an independent review and validation of the remediation works.


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10.7. Preliminaries and Approvals

In accordance with Clause 9 of SEPP 55, the remediation work is currently classified as a Category 2: Works not requiring consent. In accordance with Clause 14 of SEPP 55, Category 2 proposed works requires approval by Blacktown City Council (Consenting Authority) with submission of the RAP together with the Development Application for the Site. At least 30 days notice must be given to the Blacktown City Council, as is stipulated with Clause 16 of SEPP 55. The remediation works must also be undertaken in accordance with Guidelines and Regulations made or approved under the CLA Act 1997, the Protection of the Environment Operations (POEO) Act 1997 and the Blacktown Development Control Plan (2015). Prior to any excavation, disturbance or removal of the ACM on Site, application to obtain an Asbestos Removal Permit from SafeWork NSW is required to be undertaken by a Licensed Asbestos Removal Contractor. No other licenses or specific approvals have been identified for the remediation works at this stage. Upon provision and approval of the aforementioned approvals, the Remediation Contractor may mobilise on Site and begin the necessary preparations.

10.8. Remediation – Prior to Earthworks

10.8.1. Survey of 44 Gallon Drums / Mauser Containers An experienced Environmental Consultant should document the volumes, integrity, contents and soil surface underneath the drums of the 44 gallon drums / mauser containers scattered across the Site. This shall determine their contents (if any) and the potential associated hazards. The inventory of the drums will assist in determining the necessary handling and disposal requirements, i.e. drums with flammable contents. Where required, Waste Classification Certificates must be written for the waste present, with offsite removal by suitably qualified/licensed contractors to a facility which can legally accept the waste.

10.8.2. Dewatering Management Plan A suitably qualified Environmental Consultant / Engineer should be engaged to develop a Dewatering Management Plan (DMP) for the drainage and disposal of the dam water across the Site. The presence of faecal coliforms including E.Coli in the surface water samples (D2-South, D3-North, D3-South) collected by ADE should be addressed in the DMP with further advice and controls (if required).

10.8.3. Site Preparation Once earthworks have been approved, preparation of Civil and Earthworks Remediation Works will include:

Appointment of an appropriately qualified and experienced Remediation Contractor; Site mobilisation and installation of all required environmental and WH&S controls, in accordance with an approved Safe Work Method Statement (SWMS) / works program; Preparing the Site for remediation works (erect / repair boundary fencing and other general preparatory works) with input from the Environmental Consultant;


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Marking out remediation areas and stockpiling locations for excavated materials; and Preparation of encapsulation areas for the burial of ACM soils or waste classification of stockpiled materials before material can be removed from the Site.

10.8.4. Surficial Sources of Contamination

10.8.4.1. AoC1 – ASTs

The ASTs identified within the Site are to be removed for off-site disposal (refer to Appendix I – Areas of Concern, Figures 8 & 9). Removal of the ASTs and associated infrastructure should be undertaken in conformance with the steps outlined below:

Documented work instructions and all relevant work permits shall be prepared and issued prior to decommissioning works proceeding; All possible product shall be removed from the tanks using the normal pumping system; Dispensers and other above ground pumping equipment shall be disconnected and isolated; Any residual product shall be withdrawn via the dip or other suitable fitting, using an air operated pump or other equipment suitable for a hazardous area and a suction hose, or spear, reaching to the tank bottom. All transfer equipment shall be electrically bonded to the tanks. Transfer residual product to sealed drums or appropriate tanker for safe disposal; All ground level connections to the tanks shall be sealed off, leaving the vent intact. Locate and isolate electrical cables, product pipelines and gas lines, including LP Gas lines, in the vicinity; After removal the tanks should be transported whilst still containing vapour, and later purged in a controlled environment; All liquid waste , contents and tank should be removed by a licensed liquid waste contractor and disposed at facility licensed to receive the waste; The following typical procedures and precautions for off-site purging should be adopted:

o Drain and disconnect all redundant pipework, withdraw any tank mounted equipment, and plug all openings including the vent. One plug shall have a 3 mm hole to act as a pressure equalising vent.

o Inspect the shell of the tank for any defects. Cold patch or plug any holes prior to the loading of the tank on to the transport vehicle.

o Each tank shall be permanently marked with stencils or warning labels as follows:

NOT GAS FREE: NO SMOKING NO NAKED LIGHTS

TANK HAS CONTAINED FUEL/LEADED PETROL NOT SUITABLE FOR STORAGE OF FOOD OR LIQUIDS INTENDED FOR HUMAN OR

ANIMAL CONSUMPTION

o The labels or stencils shall be in letters at least 50 mm high, and placed so as to be visible from each side and both ends of the tank while it is being transported.

o Properly secure the tank to the transport vehicle with webbing straps, and chocked against rolling. Transport the tank upright with the vent at the top of the tank.


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Transport of tanks should be by diesel powered vehicles with exhaust systems generally in conformance with the relevant parts of AS 2809 series. All drivers should be trained to recognise the hazards associated with the operation and in appropriate emergency procedures; As far as possible, the trip to the disposal site should be uninterrupted. If it is necessary to park the vehicle for any period, it should be isolated from other vehicles and kept under observation, with the warning notices clearly visible; and A permanent record shall be kept of the tanks removal for disposal off-site. Details of the site of origin, date of removal, size of the tank, destination or name of the contractor to whom the tank has been transferred should be noted.

10.8.4.2. AoC2 – 44 Gallon Drums / Mauser Containers

During the course of the investigation, 44 gallon drums containing hydraulic oil, motor oil and unknown contents in addition to plastic “Mauser” containers were observed across the surface of the Site, specifically Fill Wedge 1 (F1), Dam (1), Warehouse 1 (W1) and 259 Riverstone Road, Riverstone (refer to Appendix I – Areas of Concern, Figures 5, 6, 7 & 9). The drums identified within the Site are to be removed for off-site disposal. The removal of the drums and associated contents should be undertaken in conformance with the steps outlined below (in general accordance with AS4976-2008 – The removal and disposal of underground petroleum storage tanks):

Documented work instructions and all relevant work permits shall be prepared and issued prior to decommissioning works proceeding i.e. hot works etc; The inventory of known 44 gallon drums should be reviewed prior to all excavation works to establish the Class of materials that were contained within the drums; Construct a bunded area to receive any exposed drums and contents; Assess the drums and identify (if possible) the contents (if any) of the drums, i.e. residual liquids and / or fill materials; Each drum (depending on class) shall be permanently marked with stencils or warning labels as follows:

NOT GAS FREE: NO SMOKING NO NAKED LIGHTS

DRUM HAS CONTAINED FLAMMABLE PRODUCTS NOT SUITABLE FOR STORAGE OF FOOD OR LIQUIDS INTENDED FOR HUMAN OR

ANIMAL CONSUMPTION

Contents may be hazardous / dangerous, remediation contractors must safely remove the inner contents of the drums i.e. a licensed liquid waste contractor if containing liquid contents. If fill material exists within the drums, it should be safely removed and classified for off-site disposal in accordance with local regulatory requirements as follows:

o If sands and / or fill materials are found within the drums, they will be appropriately removed, stockpiled in the designated bunded areas, sampled and classified in accordance with EPA waste classification guidelines; and

o Any residual liquids shall be withdrawn using an air operated pump or other equipment suitable for a hazardous area and a suction hose or spear. All transfer equipment shall be


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electrically bonded to the tanks. Transfer residual product to sealed drums or appropriate tanker for safe disposal.

As the drums may contain flammable gas / liquid / solids, the lower explosive limit (LEL) of the drums should be ascertained before they are opened i.e. any hot works or works that could create a spark. If the LEL is deemed appropriate by the remediation contractor then opening works can continue; Upon classification of the drums, suitable disposal procedures to a licensed landfill facility should be followed; Waste classification assessment of all stockpiled material (surrounding soils and drum contents) should be undertaken by the Environmental Consultant (see below); Disposal of the contaminated soils (once classified) to an appropriately licensed landfill facility, under the waste classification assigned by the Environmental Consultant or for re-use on Site; and Validation sampling of the soil surface beneath the drums shall be undertaken if the contents have been leaking or if concern exists regarding the aesthetics of the fill materials and will be compared with the Site’s RAC.

10.8.4.3. AoC3 – ‘Bonded’ ACM on Soil Surface

‘Bonded’ ACM was observed on the soil surface and throughout small spoil mounds within the demolished building footprint at 259 Riverstone Road, Riverstone NSW. Similarly, ACM was observed on the soil surface and adjacent the storage racks on the south-western side of the warehouse in Dam 1 (D1). For locations of surficial ACM across the Site refer to Appendix I – Areas of Concern, Figures 6 & 10. The following will be undertaken for asbestos removal of the soil / ground surface:

All observable ACM will be removed from the soil surface and storage racks by a Class A or B Licensed Asbestos Removalist under supervision of an experienced Occupational Hygienist; An Asbestos Materials Clearance Inspection Report will be prepared following the successful removal of ACM from the soil surface of the area; Stockpiled soil materials should be characterised as outlined in Section 10.9.6; and All ACM removed should be disposed a licensed disposal facility with tipping receipts retained for the purposes of Site validation and client records.

10.8.5. Stockpiles Generated On-Site

10.8.5.1. AoC4 – Fill Wedge 1 (F1) Stockpile

Stockpiled soil materials and general refuse is present on the south-eastern boundary of F1 with an approximate volume of 265 m3 (refer to Appendix I – Areas of Concern, Figure 7). Please refer to ADE (2017d) for details regarding previous sampling and analysis of the stockpiled soil materials. For off site disposal as per NSW EPA (2014), further TCLP samples are required to determine the leachability of Benzo(a)pyrene in sampling locations 12410-WAC1-TP7, WAC1-TP8, WAC1-TP10 and WAC1-TP11. Provided the Benzo(a)pyrene within the samples collected are below TCLP1 (0.04 mg / L) assigned for ‘General Solid Waste,’ the stockpiled soil materials are classified for off-site disposal as ‘Special Waste – Bonded Asbestos (as General Solid Waste).’


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10.8.5.2. Characterisation of Stockpiled Soil Materials

All in-situ soil materials across 280 Garfield Road East have been characterised through chemical and asbestos analysis. Pre-existing Waste Analysis and Classification Reports (ADE 2017d, 2017e) for off-site disposal are available for the stockpiled soil materials along the south-eastern boundary of F1 and imported fill materials on the embankment of D1’s north-eastern dam wall. The following process shall be adopted for unclassified stockpiles or in-situ soil materials requiring further stockpile characterisation in accordance with NEPM (2013):

Bunds shall be constructed around all stockpiles along with impermeable bases or on 0.2 mm plastic; All excavated and stockpiled materials shall be sampled to determine their potential for beneficial re-use or for off-site disposal; For the assessment of the subject stockpile, ADE recommends a minimum sampling density as prescribed in the ‘Victorian EPA Industrial Waste Resource Guidelines for Soil Sampling (2010)’ (VIC EPA 2010) as referenced in NEPM 2013; The receiving landfill should be consulted regarding any other specific testing requirements for receiving waste materials; Materials to be removed from the Site should be classified in accordance with the NSW EPA (2014) and receiving facility requirements prior to disposal to an appropriately licensed waste facility; and Copies of all consignment notes (issued as dockets or similar) for the transport, receipt and disposal of the materials should be maintained for the Site Validation and client records.

10.8.6. Subsurface Sources of Contamination

10.8.6.1. AoC5 – USTs

ADE observed an Underground Septic Tank within the property at 259 Riverstone Road, Riverstone NSW adjacent to the old building footprint (refer to Appendix I – Areas of Concern, Figure 10). The identified Septic Tank including any additional unexpected Septic Tanks that may be encountered during the remedial works should be managed and removed as below:

Hire licensed waste contractor to pump-out the liquid waste; During the pump-out, the sides, lid, baffle (if fitted) and square junctions of the system should be hosed down as the waste is removed; The inlets and outlets should be plugged and the system should be filled with clean water and disinfected to a minimum level of 5 mg/L of free residual chlorine, with a 30 minute contact time. The lid is also to be exposed to the chlorine solution. The chlorine should dissipate naturally and not be neutralised; The chlorine content should then be pumped-out by a licensed waste contractor with tipping receipts submitted to Blacktown City Council; The Septic Tank may then be removed if the structural integrity can be maintained; Validation soil sampling of the excavated walls and base of the pit, a sampling plan is outlined in Section 11; Backfilling of the excavation(s) with clean, validated materials which have been imported and verified as Virgin Excavated Natural Material (VENM) (if required); and


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Retain records for all imported VENM for final Site Validation Report.

10.9. Remediation – During Earthworks

10.9.1. Subsurface Sources of Contamination

10.9.1.1. AoC6 – Lead Hotspot

A Lead hotspot identified in fill material (to an approximate depth of 0.3 m BGL) surrounding sampling point F1.TP5A (refer to Appendix I – Areas of Concern, Figure 7) is required to be removed off site as part of the remediation works to be undertaken at the Site. The excavation and removal of the Lead hotspot should be conducted as follows:

The identification and marking of the initial estimated remediation area will be determined; Removal of sampling point F1.TP5A and immediately surrounding soils as 5 m by 5 m area to a depth of approximately 0.5 m BGL; Stockpiling and subsequent classification of the materials; Stockpiling of the excavated soils from F1.TP5A should occur within the boundaries of the remediation area, either on a designated hardstand or area covered with plastic (2mm) to minimise the potential for contaminating soils beneath; Waste classification assessment of all stockpiled material should be undertaken by the Environmental Consultant; Disposal of the contaminated soils (once classified) to an appropriately licensed landfill facility, under the waste classification assigned by the Environmental Consultant; Validation of the resultant excavations through the process of on-site observations and soil sampling/testing, as discussed in Section 12; Expanding of the excavations under the direction of the Environmental Consultant, should the validation testing show that the adopted RAC have not been achieved, followed by additional waste classification of the excavated spoil and validation sampling of the expanded excavation; Continue the process until the RAC has been achieved.

10.9.1.2. AoC7 – ‘Bonded’ ACM Soils (> HSL D)

ACM was detected in three (3) sampling depths between 0.3 m and 2.0 m BGL at sampling point D1.TP23 (refer to Appendix I – Areas of Concern, Figure 6). The concentrations of detected asbestos were above the land-use criteria, and were not suitable for placement underneath the road network without placement on a Section 149 Certificate, with accompanying EMP. As a result, the soil materials are not suitable for the proposed land use and should be disposed at a licensed waste facility. The removal and excavation of the ACM containing soils surrounding D1.TP23 should be conducted as follows:

Removal of sampling point D1.TP23 and immediately surrounding soils to the nearest lateral sampling points less than HSL D to a depth of approximately 2.5 m BGL (refer to Appendix I – Areas of Concern – Figure 6). Note, further chasing of fill materials containing ACM may be required; As a result, approximately 900 m3 will be excavated and stockpiled separately on top of 2 mm plastic and covered with a layer of high visibility geofabric materials (or equivalent) to prevent airborne dispersion of asbestos fibres;


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All excavation and movement of previously identified ‘Bonded’ ACM soils are required to be supervised by a Class A or B Licensed Asbestos Removalist and experienced Environmental Consultant / Occupational Hygienist. A relevant Asbestos Management Plan (AMP) should be developed. The AMP will address the risks associated with ACM and controls to be implemented during works to mitigate the possibility of airborne asbestos exposure to contractors, clients and visitors on Site; A relevant Waste Analysis and Classification for off site disposal is available for these soil materials as per ADE (2017e).

10.9.1.1. AoC8 – ‘Bonded’ ACM Soils (< HSL D)

For human health, the primary route of exposure to asbestos dust and asbestos is identified to be through the inhalation of asbestos containing dust and asbestos fibres. Re-use of soil materials containing ACM below the landuse criteria for roads (i.e. HSL D) is the preferred remediation / management method. Implementation of the Site’s AMP ensures exposure to asbestos is not possible to potential receptors following remediation. Following the excavation and removal of the Lead and ‘Bonded’ ACM impacted soil materials (AoC6 and AoC7), the remaining fill materials within F1 and D1 are to be stripped in one (1) metre intervals until residual natural soils are encountered / all fill materials have been removed / required RL is achieved. This should be undertaken with the supervision of an experienced Environmental Consultant / Occupational Hygienist in order to, limit the extent of possible unexpected ACM contamination and prevent cross-contamination of soil materials. Fill materials containing ‘Bonded’ ACM with a SAC below HSL D will be immediately tipped at the prepared excavations within the road footprints. If necessary, temporary stockpiles will be created of similar material to account for the logistics and staging of the excavation works. Please see below for a comprehensive overview of the asbestos abatement methodology required for remediation of the ACM containing soils present in Fill Wedge 1 (F1) and Dam 1 (D1):

ACM soils identified less than HSL D should be stripped incrementally at 1 m intervals. The soil surface will be emu picked for any identifiable pieces of presumed asbestos containing fibre cement at each 1 m interval (including current ground level) prior to being transported to the designated road alignment areas; To be completed under bonded asbestos conditions with airborne asbestos monitoring at both the load-out and encapsulation areas and supervision by a experienced Occupational Hygienist and Licensed Class B or higher Asbestos Removalist; Prior to and during the load-out of the bonded soil materials dust suppression is required through saturation of the soil materials with water; Transport and disposal of asbestos waste material within the designated broad alignment areas; Once tipped, a 300 mm thick layer is to be evenly spread across the required area in 300 mm layers or a thickness advised by a qualified Geotechnical Engineer. A licensed asbestos removalist with inspect and emu pick the entire area before a visual confirmation is approved by the Occupational Hygienist prior to compaction with the roller; and This process is to be repeated following every 300 mm layer to reduce the potential for the compaction and deterioration of asbestos containing fibre cement pieces and possible release of airborne asbestos fibres; and


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Once the required RL is achieved within the encapsulation area beneath the road footprint, a visual Asbestos Materials Clearance Inspection will be undertaken to ensure no ACM remains on the soil surface; A marker layer of highly visible geogrid or geofabric material should be placed across the encapsulation area followed by the engineered subgrade, sub-base, sands and asphalt layer.

10.10. Additional Investigations

10.10.1. Data Gaps – Base of Dams Following dewatering of the dams across the Site, sampling of the surface soil materials on the base of the dams should be undertaken by an experienced Environmental Consultant:

Ramps or equivalent shall be constructed for the safe access to the base of the dams; Dumped or present materials at the base of dams will be assessed for the requirement of remediation; Sampling and analysis shall be conducted in accordance with the sampling guidelines for contaminated sites in NSW EPA (1995) with samples collected between 0.0 m to 0.3 m BGL below the base of the dam; and The surface soil results will be compared against the SAC for HIL-A / HSL-A to remain on-site.

10.10.2. Unexpected Finds – Soil and Groundwater Contamination Although the Site has been investigated in compliance with relevant NSW EPA endorsed guidelines, there remains a potential for unexpected soil and groundwater contamination to be present between sampled locations. In the event that further areas of potential contamination are found during the civil earthworks and remediation works, the following procedure ensues:

Upon discovery of further potential sources of contamination, the client will be notified and the area barricaded; Visual identification of the nature and likely extent of the potential contamination by the Environmental Consultant; Appropriate investigation with a view to identifying the nature and extent of the contamination to be conducted by the Environmental Consultant; If contamination is found and remediation action or management is considered necessary, an addendum or supplement to the RAP will be prepared by the Environmental Consultant; and The additional remediation will be implemented by the Remediation Contractor and validated by the Environmental Consultant.


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11. VALIDATION AND MONITORING

11.1. Validation

Upon the completion of the remediation works within the Site, a qualified Environmental Consultant should undertake validation sampling and inspection. As the remediation involves the excavation and movement of ACM and Lead impacted soils, a qualified Environmental Consultant is recommended to be involved during the remediation works to ensure compliance with the RAP and the appropriate controls are in place. A validation (Phase IV) assessment report shall be prepared in accordance with the NSW EPA Guidelines for Consultants Reporting on Contaminated Sites (2011) and other relevant and appropriate guidelines. The validation report shall confirm that the Site has been remediated to a suitable standard for the proposed land-use and that no related adverse human health and environmental effects have occurred or likely to occur as a result of the remediation works. The validation report shall also include details of the capping layers (i.e. design specifications and visual validation of the placed ACM fill layers, total volume of contaminated materials and soils removed off-site, disposal receipts once materials are transported to an EPA licensed landfill, any relevant information regarding future or on-going management requirements, notification mechanisms, Environmental Management Plans (if required) and Asbestos Clearance Inspection Reports for areas where asbestos handling have been undertaken. The validation program will involve validation sampling in order to provide quantitative analysis of the Site’s suitability for the proposed development. This will include sampling of the base and walls of any excavations.

11.2. Sample Collection and Holding

If applicable, ADE’s standard decontamination procedures shall be undertaken prior to sampling events to avoid the possibility of cross-contamination. The soil sampling equipment and items likely to come into contact with soil samples will be thoroughly washed followed by rinsing with phosphate-free detergent and deionised water before the collection of samples. Due care should be taken with the disposal of any washings and residues from such cleaning operations. A field observation log will be kept by sampling personnel. Details recorded in the log included:

Sample number; Soil profile notes; Sampling method; Sample identification; Sample description; and Sample point measurements.


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Telephone:

Internet:

ABN:



NSW: (02) 8541 7214 VIC: 1300 796 922


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A comprehensive master sample register will be maintained. As samples are received, they will be given a unique sequential number from the sample register into which details from the labels will be entered. Before packing and dispatch of samples for analysis, a Chain of Custody will be completed. This form recorded details of the individual samples being dispatched and the type of analysis required for each sample.

11.3. Quality Assurance Plan

Quality Assurance (QA) and Quality Control (QC) procedures will be adopted throughout the field sampling program. All samples shall be analysed by NATA Accredited Laboratories using tests in accordance with the NEPM (2013) Guidelines. If the QA/QC samples meet the assigned criteria of valid results for:

Laboratory duplicate samples 95% Laboratory blank samples 100% Laboratory spike samples 95% Laboratory control samples 95% Blind replicate samples 95% Rinsate samples 75% Spiked VOC trip samples 75% Trip blank samples 95% Field replicate measurements 75%.

With overall completeness of 95%, then the data collected in the course of the investigation will be considered valid and acceptable.

11.4. Data Quality Objectives

The validating report shall be conducted in accordance with the Data Quality Objectives (DQOs) and QA/QC procedures to ensure the repeatability and reliability of the results. A checklist of Data Quality Indicators (DQI) in accordance with the NSW Site Auditor Scheme (2nd Ed.) will be undertaken as part of the validation assessment. The validation assessment will be planned in accordance with the following DQOs:

State the Problem; Identify the Decision; Identify Inputs to the Decision; Define the Boundary of the Assessment; Develop a Decision Rule; Specify Acceptable limits on Decision Errors; and Optimise the Design for Obtaining Data.


Victoria Office:

Telephone:

Internet:

ABN:



NSW: (02) 8541 7214 VIC: 1300 796 922


14 617 358 808

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11.5. Soil Sampling and Visual Validation of AoC

11.5.1. Validation Sampling of Soils Potentially Impacted from ASTs (AoC1) The validation soil sampling program outlined should undertaken following the remediation of surface soils underlying the ASTs and / or hydrocarbon impacted soils:

The soil surface underlying the AST should be visually inspected for signs of potential contamination; If contamination is observed, the footprint of the previously overlying AST should be excavated to extents determined by the Environmental Consultant; A combination of visual and PID screening should be adopted to ensure that the potentially contaminated soils have been adequately removed; Upon removal of the AST, one (1) soil sample per 25 m2

should be collected from surface soils; Detailed record of observations including photographs taken throughout the removal and validation; Blind replicate samples should be collected at a rate of one (1) sample per 20 soil samples collected. Split samples should be collected at a rate of one (1) sample per 20 soil samples collected; A Trip Blank, VOC spike and rinsate sample should also be collected during sampling operations to ensure that sampling is undertaken in accordance with all relevant QA / QC requirements; All samples should be analysed for Volatile Organic Compounds (VOCs) by a NATA accredited laboratory; and Provided that all samples yield concentrations below the adopted remediation assessment criteria, a Phase IV Validation Report can be produced; and If unexpected USTs are encountered during the earthworks, the validation sampling rates outlined in NSW Government – Environment, Climate Change and Water UPSS Technical Note: Site Validation Reporting (January 2010) should be followed.

11.5.2. Validation Sampling for 44 Gallon Drum / Mauser Containers Removal (AoC2) Following surveying works and removal of the 44 gallon drums and mauser containers as outlined in Section 10.8.1 and Section 10.8.4.2, drums and containers noted with a damaged integrity or visually deemed to have leaked contents into the underlying soil materials will be further assessed through validation soil sampling. Validation soil sampling and screening should be undertaken at the following sampling rate:

A combination of visual and PID screening should be adopted to ensure that the potentially contaminated soils have been adequately removed; Upon removal of the surface drums, one (1) soil sample per 25 m2

should be collected from surface soils; Detailed record of observations including photographs taken throughout the removal and validation; Blind replicate samples should be collected at a rate of one (1) sample per 20 soil samples collected. Split samples should be collected at a rate of one (1) sample per 20 soil samples collected; A Trip Blank, VOC spike and rinsate sample should also be collected during sampling operations to ensure that sampling is undertaken in accordance with all relevant QA / QC requirements; All samples should be analysed for VOCs by a NATA accredited laboratory; and Provided that all samples yield concentrations below the adopted remediation assessment criteria, a Phase IV Validation Report can be produced.


Victoria Office:

Telephone:

Internet:

ABN:



NSW: (02) 8541 7214 VIC: 1300 796 922


14 617 358 808

of 60

11.5.3. Visual Clearance Inspection of ‘Bonded’ ACM on Soil Surface (AoC3 and AoC4) All observable ACM should be removed from the soil surface by a Licensed Asbestos Removalist under supervision by an experienced Occupational Hygienist with implemented controls outlined in the Site’s AMP. An Asbestos Materials Clearance Report will be issued to the remediation contractor confirming all ACM is removed from the soil surface. All ACM removed should be disposed a licensed disposal facility with tipping receipts retained for the purposes of Site validation and client records. If ACM is suspected of extending into the subsurface, further visual assessment and sampling are required for adequate removal of the impacted surface soils. Following a visual inspection, collection of 10 L/500ml soil samples will be conducted to ascertain that the residual soils are suitable for the proposed residential land use, or whether the materials are required to be removed offsite to a waste facility licensed to receive the materials.

11.5.4. Validation Sampling of Soils Potentially Impacted from USTs (AoC5) Validation sampling should be undertaken subject to the completion of remediation works (as outlined in Section 11.9.5.1) within AOC4. Validation sampling should be undertaken at the following sampling rate:

Prior to validation works, a soil sample should be collected from Site and analysed for Heavy Metals (M8), Faecal Coliforms, E.Coli and Salmonella as provision of background ranges for the microbiological nature of the soil. These values will be utilised as a comparison against the validation soil samples collected after the remvoval of the septic tank; A systematic sampling pattern should be applied to the area of remediation, with sampling points evenly spaced across the walls and the bottom of all excavated pits; A minimum of five (5) soil samples should be collected from the area of the removed Septic Tank, this comprises one (1) soil sample from each wall of the excavation and an additional sample to be collected from the floor of the excavation; Should the lateral distance of the walls of the remediated area exceed 8.5 linear metres additional validation samples will be required. Lateral validation samples are to be collected at a rate of 1 per 8.5 linear metres along each wall; Should the validation samples fail, further excavation works are required until the RAC is achieved; Additional samples may be required if the excavation exceeds 1 m BGL. Samples should be taken at a sampling rate each 1 m of strata on the walls of the excavation; Excavated soil materials should be characterised as outlined in Section 10.9.6. Blind replicate samples should be collected at a rate of one (1) sample per ten (10) soil samples collected; Split samples should be collected at a rate of one (1) sample per twenty (20) soil samples collected; A Trip Blank, VOC spike and rinsate sample should also be collected during sampling operations to ensure that sampling is undertaken in accordance with all relevant QA/QC requirements; All samples should be analysed for Heavy Metals (M8), Faecal Coliforms, E.Coli, Salmonella and Chlorine by a NATA accredited laboratory; and Provided that all samples yield concentrations below the adopted RAC criteria for the Site (HIL-A), a Phase IV Validation Report can be produced.

remediation action plan - home - blacktown city · 2018. 1. 25. · 1210. env. roi nmental porectit...

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