FINAL REPORT EPAReference · FINAL REPORT EnvironmentalProtection Authority South Australia Stage3 Beverley Assessment Works. EPAReference: 05/22106. 26April 2016 51350_RP02_Rev2

FINAL REPORT

Environmental Protection Authority South Australia

Stage 3 Beverley Assessment Works

EPA Reference: 05/22106

26 April 2016

51350_RP02_Rev2

Table of Contents

Abbreviations ......................................................................................................................... vii

Executive Summary................................................................................................................. ix

1. Introduction...................................................................................................................1

1.1 Objectives ............................................................................................................1

2. Background....................................................................................................................3

2.1 Soil .......................................................................................................................3

2.2 Groundwater .......................................................................................................3

2.3 Soil Vapour ..........................................................................................................3

2.4 Crawlspace ..........................................................................................................4

2.5 Indoor Air.............................................................................................................4

2.6 Service Pits...........................................................................................................4

2.7 Outdoor Air..........................................................................................................4

2.8 Vapour Intrusion Assessment..............................................................................4

2.9 Human Health Risk Assessment ..........................................................................4

2.10 Conceptual Site Model ........................................................................................5

3. Environmental Setting ...................................................................................................6

3.1 Topography .........................................................................................................6

3.2 Geology................................................................................................................6

3.3 Regional and Local Hydrogeology .......................................................................6

3.3.1 Water Level of the Q1 Aquifer .............................................................6

3.3.2 Groundwater Flow Direction of the Q1 Aquifer ..................................6

3.3.3 Hydraulic Gradient of the Q1 Aquifer ..................................................7

3.3.4 Hydraulic Conductivity of the Q1 Aquifer ............................................7

3.3.5 Porosity of the Q1 Aquifer ...................................................................7

3.3.6 Recharge of the Q1 Aquifer .................................................................7

4. Chemicals of Interest .....................................................................................................8

5. Scope of Work ...............................................................................................................9

6. Soil Investigation..........................................................................................................10

6.1 Methodology .....................................................................................................10

6.2 Adopted Screening Levels .................................................................................12

6.3 Quality Assurance / Quality Control..................................................................12

6.4 Soil Results.........................................................................................................12

6.4.1 Field Observations .............................................................................12

6.4.2 Analytical Results ...............................................................................12

7. Groundwater Investigation..........................................................................................14

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 i

7.1 Methodology .....................................................................................................14

7.1.1 Groundwater Well Installation ..........................................................14

7.1.2 Groundwater Sampling ......................................................................17



7.4 Groundwater Results.........................................................................................18

7.4.1 Field Observations .............................................................................18

7.4.2 Standing Water Levels & Hydrogeology ............................................18

7.4.3 Water Quality Parameters .................................................................21


8. Soil Vapour Investigation.............................................................................................25

8.1 Methodology .....................................................................................................25

8.1.1 Soil Vapour Probe Installation ...........................................................25

8.1.2 Soil Vapour Sampling .........................................................................29


8.2.1 Australian Screening Levels ...............................................................31

8.2.2 United States Environment Protection Agency .................................31


8.4 Soil Vapour Results............................................................................................32

8.4.1 Field Measurements ..........................................................................32


9. Discussion ....................................................................................................................38

9.1 Temporal Trends ...............................................................................................38

9.1.1 Groundwater......................................................................................38

9.1.2 Soil Vapour .........................................................................................38

9.2 TCE Groundwater Vs Soil Vapour Plume Extent................................................38

10. Conceptual Site Model ................................................................................................40

10.1 Known and Potential Sources of Contamination ..............................................40

10.2 Extent of Environmental Impact .......................................................................41

10.2.1 Soil......................................................................................................41

10.2.2 Groundwater......................................................................................41

10.2.3 Soil Vapour .........................................................................................41

10.3 Preferential Pathways .......................................................................................42

10.4 Building Design ..................................................................................................42

10.5 Potential Human Receptors ..............................................................................42

10.6 Potential Ecological Receptors ..........................................................................43

10.7 Potential Human Exposure Pathways ...............................................................43

10.8 Diagrammatic Representation of the Site.........................................................43

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 ii

11. Soil Vapour Fate and Transport Modelling..................................................................45

11.1 Characterisation of Residential Zones within the Broadened Assessment Area Based on Soil Vapour Data ................................................................................45

11.2 Derivation of Preliminary Site Specific TCE Groundwater Concentration Response Ranges...............................................................................................48

11.2.1 Adopted Modelling Package ..............................................................48

11.2.2 Adopted Model Parameters ..............................................................48

11.2.3 Modelling Results...............................................................................50

11.2.4 Comparison to Golder (2015e) Attenuation Factor Classification Model .................................................................................................50

11.2.5 Uncertainty and Sensitivity Assessment ............................................51

11.2.6 Conclusion..........................................................................................52

12. Groundwater Fate and Transport Modelling Summary ..............................................53

13. Conclusions ..................................................................................................................56

14. Limitations ...................................................................................................................58

15. References ...................................................................................................................59

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 iii

List of Tables Table 2.1: Summary of Number of Properties Within Each Response Range .........................5

Table 3.1: Hydraulic Conductivity Data....................................................................................7

Table 4.1: Summary of the Properties of the Chemicals of Interest .......................................8

Table 6.1: Summary of Soil Sampling Methodology ..............................................................10

Table 6.2: Summary of Soil Analytical Schedule ....................................................................11

Table 6.3: Summary of Soil Moisture Results for 2 and 4 mbgl Samples ..............................13

Table 7.1: Groundwater Monitoring Well Construction Details ............................................15

Table 7.2: Reduced Water Levels – February 2016 ...............................................................19

Table 7.3: Groundwater Concentrations Exceeding Adopted Screening Levels....................22

Table 8.1: Soil Vapour Probe Construction Summary............................................................27

Table 8.2: Soil Vapour Concentrations Exceeding Adopted Screening Levels .......................33

Table 9.1: Summary of Groundwater TCE Concentrations in April /May 2015 and February 2016 for Available Groundwater Wells...........................................................38

Table 10.1: Summary of Likely TCE Source Areas ..................................................................41

Table 11.1: Attenuation Factors for Beverley Assessment Area (Golder, 2015e) .................45

Table 11.2: Summary of Response Range Classification for the Broadened Assessment Area (From Soil Vapour Data) .................................................................................46

Table 11.3: Summary of Adopted Building Parameters for Vapour Intrusion Modelling (From Groundwater Concentrations) .............................................................49

Table 11.4: Summary of Adopted Soil Parameters for Vapour Intrusion Modelling (From Groundwater Concentrations)........................................................................50

Table 11.5: Summary of Proposed Preliminary Site Specific TCE Groundwater Concentration Response Ranges ............................................................................................50

Table 11.6: Effects on the Preliminary Site Specific TCE Groundwater Concentration Response Ranges with Adjusted Model Parameter Values............................52

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 iv

List of Figures Figure 1 – Site Location Plan ....................................................................................................2

Figure 4 – Inferred Dissolved Phase TCE Groundwater Plume: February 2016.....................23

Figure 6 – Inferred TCE Soil Vapour Plume: February 2016...................................................35

Figure 9 – Preliminary Response Range Classification for Residential Zones Within the

Figure 2 – Groundwater Well Location Plan ..........................................................................16

Figure 3 – Inferred Groundwater Flow Direction: February 2016 .........................................20

Figure 5 – Soil Vapour Probe Locations .................................................................................28

Figure 7 – Conceptual Site Model ..........................................................................................44

Figure 8 – TCE Indoor Air Response Ranges (Government of South Australia, 2014)...........45

Assessment Area and Broadened Assessment Area ......................................47

Figure 10 – Proposed Groundwater Prohibition Area ...........................................................55

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 v

Appendices Summary Tables

Appendix A Piper Plot for Groundwater Well – February 2016

Appendix B Quality Assurance / Quality Control Review

Appendix C Soil Laboratory Certificates of Analysis and Chain of Custody Documentation

Appendix D Well Permits

Appendix E Groundwater Well Logs and Groundwater Well Construction Details

Appendix F Photographs of Available Groundwater Well and Soil Vapour Probe Soil Cores

Appendix G Disposal Receipts from Licenced Waste Contractor

Appendix H Groundwater Well Post Installation Development Field Sheets (MW08‐MW18)

Appendix I Survey Data

Appendix J Groundwater Sampling Field Sampling Sheets

Appendix K Groundwater Laboratory Certificates of Analysis and Chain of Custody Documentation

Appendix L Soil Vapour Probe Logs and Soil Vapour Probe Construction Details

Appendix M Summa Canister Soil Vapour Field Sampling Sheets

Appendix N Carbon Tube Soil Vapour Field Sampling Sheets

Appendix O Soil Vapour Laboratory Certificates of Analysis and Chain of Custody Documentation

Appendix P TCE Indoor Air Response Level Classification Calculations

Appendix Q Proposed Preliminary Site Specific TCE Groundwater Concentration Response Range Model Inputs and Outputs

Appendix R Theoretical Indoor Air Concentration Calculation from Groundwater Model and Attenuation Model, and Response Level Classifications

Appendix S Groundwater Fate and Transport Modelling

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 vi

Abbreviations

Term Definition

API American Petroleum Society

AS Australian Standards

ASTM American Society for Testing and Materials

BTEX Benzene, Toluene, Ethylbenzene, Xylenes

COC Chain of Custody

CRC CRC for Contamination Assessment and Remediation of the Environment

CSM Conceptual Site Model

DO Dissolved Oxygen

EC Electrical Conductivity

EPA Environment Protection Authority South Australia

GPA Groundwater Prohibition Area

GME Groundwater Monitoring Event

HHRA Human Health Risk Assessment

inHg Inches of Mercury

ITRC Interstate Technology & Regulatory Council

km Kilometres

LDPE Low Density Polyethylene

LOR Limit of Reporting

m Metres

mbgl Metres Below Ground Level

mg/kg Milligrams per Kilogram

MGT Eurofins MGT

ml Millilitres

mg/L Milligrams per Litre

NAPL Non‐Aqueous Phase Liquid

NATA National Association of Testing Authorities

NC Not Calculated

ND Not Detected

NEPC National Environmental Protection Council

NEPM National Environment Protection Measure

PID Photoionisation Detector

ppm Parts Per Million

ppb Parts Per Billion

QA/QC Quality Assurance/Quality Control

RPD Relative Percent Difference

RSLs Regional Screening Levels

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 vii

Term Definition

TDS Total Dissolved Solids

TPH Total Petroleum Hydrocarbons

TRH Total Recoverable Hydrocarbons

US EPA United States Environmental Protection Agency

VOCs Volatile Organic Compounds

µg/m3 Micrograms per cubic metre

‐ On tables is "not calculated", "no criteria" or "not applicable"

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 viii

Executive Summary

JBS&G Australia Pty Ltd (JBS&G) was engaged by the Environmental Protection Authority South Australia (EPA) to undertake the ‘Beverley Stage 3 Assessment Works’ for the Assessment Area and Broadened Assessment Area in Beverley, South Australia (the site).

The EPA has been undertaking environmental assessment works relating to chlorinated hydrocarbons in the Assessment Area since 2015 – it is noted works within the Broadened Assessment Area have not been undertaken previously. The assessment works previously commissioned by EPA have comprised of groundwater, soil vapour, crawl space, sub‐slab and indoor air vapour sampling. Following completion of these works and receipt of results, the EPA considered that further works (Stage 3) were necessary to characterise the lateral extent of the chlorinated hydrocarbon contamination in groundwater and soil vapour.

The objectives of the Beverley Stage 3 Assessment Works were as follows:

Characterise the lateral and vertical extent of the chlorinated hydrocarbon soil vapour contamination.

Characterise and determine any confounding sources of contaminating activities and associated chemicals of interest.

Delineate the chlorinated hydrocarbon groundwater contamination for the purpose of establishing a groundwater prohibition area (GPA).

Determine (and identify) potential source contribution locations, including locations of former (or existing) contaminating activities contributing to the widespread chlorinated hydrocarbon contamination in groundwater and soil vapour.

The works undertaken were completed in order to address the above objectives and included the installation of 11 additional groundwater wells and installation of soil vapour probes at 15 additional locations, with nested probes to multiple depths installed at 10 of these locations. Groundwater monitoring from a total of 20 groundwater wells and soil vapour monitoring from a total of 24 locations (many locations with multiple depths) was completed following the installation works. Following the receipt of the laboratory results, an update of the Conceptual Site Model (CSM), soil vapour fate and transport modelling and 3D groundwater fate and transport modelling were undertaken. The purpose of the soil vapour fate and transport modelling was to determine theoretical trichloroethene (TCE) Indoor Air Response Range classifications (Government of South Australia, 2014) for residential properties within the Broadened Assessment Area, and also to determine preliminary site specific TCE groundwater concentrations for each of the TCE Indoor Air Response Range classifications (Government of South Australia, 2014). The 3D groundwater fate and transport modelling was undertaken in order to define a boundary for the purpose of establishing a groundwater prohibition area (GPA).

Subject to the limitations in Section 14 of this report, the following was concluded:

No evidence of soil contamination was noted in the field, and all soil results were below the laboratory report limits for the chemicals of interest. The pH and moisture content results were similar to those reported previously by Golder (2015a‐c).

The groundwater flow direction was inferred to be in a north‐westerly direction based on the February 2016 data. This compares with the westerly direction previously reported by Golder (2015a).

Tetrachloroethene (PCE), TCE, cis‐1,2‐dichloroethene (cis‐1,2‐DCE), 1,1‐dichloroethene (1,1‐DCE), vinyl chloride (VC), 1,1‐dichloroethane (1,1‐DCA), 1,2‐dichloroethane (1,2‐DCA), 1,1,2‐

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 ix

trichloroethane (1,1,2‐DCA), bromodichloromethane, chlorodibromomethane, chloroform, toluene and total recoverable hydrocarbon (TRH) fraction C6‐C10 (as consistent with the concentrations of the volatile organic compounds [VOCs]) were reported at concentrations above the laboratory limits of reporting (LOR) in groundwater. TCE, 1,1‐DCE, VC and TRH C6‐C10 were reported at concentrations above the adopted groundwater screening levels, as follows:

o TCE exceeded the World Health Organisation (WHO) (2011) drinking water criteria, the Australia and New Zealand Environment and Conservation Council (ANZECC) (2000) freshwater criteria and the ANZECC (2000) marine water criteria;

o 1,1‐DCE exceeded the WHO (2011) drinking water criteria; o VC exceeded the WHO (2011) drinking water criteria; and o TRH C6‐C10 exceeded the National Environment Protection (Assessment of Site

Contamination) Measure (NEPM) (National Environment Protection Council [NEPC], 1999 as amended 2013) groundwater health screening levels (HSLs) for vapour intrusion for residential landuse.

Where present, historic results were similar to those reported in the February 2016 groundwater monitoring event and there was no general increasing or decreasing trend present across all locations. The extent of groundwater TCE plume has not been laterally delineated to the adopted groundwater drinking criteria of 20 µg/L at this time in the majority of directions.

PCE, TCE, cis‐1,2‐DCE and 1,1‐DCE were reported at concentrations above the LOR in soil vapour. TCE and cis‐1,2‐DCE were reported at concentrations above the NEPM (NEPC, 1999 as amended 2013) interim soil vapour health investigation levels (HILs) for residential and commercial landuse. Where present, historic results were generally similar to those reported in the February 2016 soil vapour monitoring event with the exception of one location (SV06‐6.5m) where a significantly higher TCE concentration was reported in February 2016 (3,300 µg/m3) compared to that reported in April 2015 (33 µg/m3). In general, concentrations reported in the February 2016 monitoring event were slightly higher than those previously reported, however, it is noted that higher vapour concentrations are expected in summer due to higher temperatures and lower soil moisture contents in shallow soils.

The soil vapour TCE distribution is generally consistent with the groundwater TCE distribution with the possible exception of the elevated soil vapour concentration reported at SV115‐2m. It is noted there is no groundwater well in close proximity to SV115.

Three likely source areas have been identified, occurring at the following locations:

o In vicinity of the intersection of Lancelot Street and Charles Road, and Lancelot Street and William Street;

o In vicinity of (and potentially to the east of) the southern end of Howards Road (south of Woolgina Street); and

o In vicinity of the intersection of Main Street with West Street / Willis Street (and potentially east of Port Road).

An additional three potential source areas have been identified, however, further assessment is required in order to assess the likelihood of these areas being source areas.

Theoretical indoor air concentrations calculated using the Golder (2015e) attenuation factors and the February 2016 soil vapour data were consistent with those previously

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 x

http:SV06-6.5m

calculated by Golder (2015f) and the theoretical TCE Indoor Air Response Range classifications previously applied. Classification of residential properties within the Broadened Assessment Area (based on the Golder [2015e] attenuation factors and the February 2016 soil vapour data) indicated areas of ‘Validation’, ‘Investigation’ and ‘Intervention’ were present.

3D fate and transport modelling was completed for the groundwater TCE plume. A GPA was proposed for the area, as based on the likely migration of the groundwater TCE plume over 100 years and an acceptable TCE groundwater concentration of less than 10 µg/L.

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 xi

1. Introduction

JBS&G Australia Pty Ltd (JBS&G) was engaged by the Environmental Protection Authority South Australia (EPA) to undertake the ‘Beverley Stage 3 Assessment Works’ for the Assessment Area and Broadened Assessment Area in Beverley, South Australia (the site).

The Assessment Area and Broadened Assessment Area is shown in Figure 1.

The EPA has been undertaking environmental assessment works relating to chlorinated hydrocarbons in the Assessment Area since 2015 – it is noted works within the Broadened Assessment Area have not been undertaken previously. The assessment works previously commissioned by EPA have comprised of groundwater, soil vapour, crawl space, sub‐slab and indoor air vapour sampling. Following completion of these works and receipt of results, the EPA considered that further works were necessary to characterise the lateral extent of the chlorinated hydrocarbon contamination in groundwater and soil vapour.

The Beverley area has an extensive history of industrial activity with numerous potentially contaminating activities that may have contributed to the known contamination. Due to the widespread nature of the activities undertaken and land redevelopment over time, the exact locations of potential source areas have not been identified within the EPA Assessment Area to date. The determination of source locations and delineation of the contamination plume is the focus of this scope of works.

This report presents the background, methodology and results of the Stage 3 Assessment Works.

1.1 Objectives

The objectives of the Stage 3 Assessment Works were as follows:

Characterise the lateral and vertical extent of the chlorinated hydrocarbon soil vapour contamination.

Characterise and determine any confounding sources of contaminating activities and associated chemicals of interest.

Delineate the chlorinated hydrocarbon groundwater contamination for the purpose of establishing a groundwater prohibition area (GPA).

Determine (and identify) potential source contribution locations, including locations of former (or existing) contaminating activities contributing to the widespread chlorinated hydrocarbon contamination in groundwater and soil vapour.

©JBS&G Australia Pty Ltd | 51350_RP02_Rev2 1

Z

Legend:

Job No: 51350 Client: SA EPA Version: FINAL Date: 18-Apr-2016 Drawn By: TB Checked By: KC Scale at A4

Coor. Sys. GDA 1994 MGA Zone 54 Stage 3 Beverley Broadened EPAAssessment Area, Beverley, South Australia SITE LOCATION

FIGURE 1

! Site Location ( EPA Assessment Area Broadened EPA Assessment Area

1:25,000

0 500 1,000 metres

Document Path: W:\Projects JBSG Australia\Adelaide\51350_SA EPA_ Beverley_Stage 3\ArcGIS\Maps\Site Location.mxd Image Reference: www.nearmap.com© - Imagery Date: 6 February 2016 and Google Maps © 2016

http:www.nearmap.com

2. Background

As discussed above, EPA commissioned a number of environmental investigations for the Assessment Area in 2015. The following reports pertain to these works:

Golder Associates Pty Ltd (2015a) Groundwater and Soil Vapour Data Report – Beverley Assessment Area, South Australia. Reference: 1418522‐003‐R‐Rev1, dated 27 May 2015.

Golder Associates Pty Ltd (2015b) Beverley Assessment Area, South Australia – Stage 2 Vapour Monitoring Data Report (June 2015). Reference: 1418522‐010‐R‐Rev0, dated 7 July 2015.

Golder Associates Pty Ltd (2015c) Beverley Assessment Area, South Australia – Stage 3 Vapour Monitoring Data Report (July‐August 2015). Reference: 1418522‐012‐R‐Rev0, dated October 2015.

Golder Associates Pty Ltd (2015d) Beverley Assessment Area, South Australia – Stage 4 Indoor Air Data Report (August‐September 2015). Reference: 1418522‐020‐R‐Rev0, dated October 2015.

Golder Associates Pty Ltd (2015e) Beverley Assessment Area, South Australia – Preliminary Vapour Intrusion Assessment. Reference: 1418522‐021‐R‐Rev0, dated October 2015.

Golder Associates Pty Ltd (2015f) Beverley Assessment Area, South Australia – Preliminary Human Health Risk Assessment. Reference: 1418522‐022‐R‐Rev0, dated October 2015.

Golder Associates Pty Ltd (2015g) Beverley Assessment Area, South Australia – Conceptual Site Model. Reference: 1418522‐002‐R‐Rev0, dated October 2015.

The key findings of the above reports are outlined below in Section 2.1 to 2.10.

2.1 Soil

Soil sampling was completed as part of the groundwater well and soil vapour probe installation, with the major focus of analysis being geotechnical and moisture content rather than the chemicals of interest. The geotechnical parameters and moisture content data was incorporated into the vapour fate and transport modelling. Where the chemicals of interest were analysed, all concentrations were below the laboratory limit of reporting (LOR).

2.2 Groundwater

The major chemical of interest identified at the site is trichloroethene (TCE). The highest TCE concentration reported in groundwater in the above investigations was 2,700 µg/L at MW03. Other chlorinated hydrocarbons have also been reported in groundwater, including tetrachloroethene (PCE), cis‐1,2‐dichloroethene (cis‐1,2‐DCE), trans‐1,2‐dichloroethene (trans‐1,2‐DCE), 1,1‐dichloroethene (1,1‐DCE) and vinyl chloride (VC). Cis‐1,2‐DCE, trans‐1,2‐DCE, 1,1‐DCE and VC are breakdown products of TCE.

In addition to the above, other volatile organic compounds (VOCs) including 1,1,2‐trichloroethane, 1,2‐dichloroethane, 1,2‐dichloropropane and chloroform have been reported in groundwater.

2.3 Soil Vapour

As TCE and its breakdown products are volatile chemicals, soil vapour investigations have also been completed. Of the above chemicals reported at elevated concentrations in groundwater, PCE, TCE, cis‐1,2‐DCE and chloroform were also reported at elevated concentrations within soil vapour. The maximum TCE concentration reported in soil vapour in the above investigations was 120,000 µg/m3

at SV01‐M, which is installed to a depth of 3.85 mbgl. The elevated TCE concentrations in soil


vapour are expected to drive the vapour risks associated with the site, and hence TCE is the only chemical discussed below in Sections 2.4 to 2.9.

2.4 Crawlspace

Elevated TCE concentrations have been reported in the crawlspaces of residential dwellings. The maximum TCE concentration reported within a crawlspace to date is 45 µg/m3 at Property 10‐Location 1.

2.5 Indoor Air

Elevated TCE concentrations have been reported within residential dwellings. The maximum TCE concentration reported within a residential dwelling to date is 41 µg/m3 at Property 7‐Location 4.

2.6 Service Pits

Elevated TCE concentrations have been reported within some service pits within the Assessment Area. The maximum TCE concentration reported within a service pit to date is 19 µg/m3 at P3 (electrical service pit).

2.7 Outdoor Air

PCE, TCE and chloroform were reported at concentrations above the LOR in outdoor air samples within the Assessment Area. Cis‐1,2‐DCE, trans‐1,2‐DCE and VC were reported at concentrations below the LOR.

2.8 Vapour Intrusion Assessment

The Golder (2015e) vapour intrusion assessment was competed using the Johnson and Ettinger (1991) model to determine a vapour attenuation factor (ie a factor by which the soil vapour concentration from a given depth decreases due to diffusion, degradation, mixing, dispersion, partitioning and upward migration through overlying soils / concrete [where present] and into the ambient / indoor air before being inhaled).

Vapour fate and transport modelling was completed to determine an attenuation factor for slab on grade and crawlspace residential dwelling types. The estimated attenuation factor from a depth of 0.85 m to indoor air for both slab on grade and crawlspace dwelling types was adjusted to be consistent with average values reported during sampling.

Model estimated (and adjusted model estimated) crawlspace and indoor air concentrations from depths of 0.85 m and subslab depths were compared to site data for the available properties. The model estimated concentrations were found to be higher than the site data, while the adjusted model estimated concentrations were found to be within the same order of magnitude as the site data.

2.9 Human Health Risk Assessment

The Golder (2015f) Human Health Risk Assessment (HHRA) was based on the outcomes of the above vapour intrusion assessment (Golder, 2015e). The HHRA characterised 11 properties as to their theoretical TCE Indoor Air Response Range (Government of South Australia, 2014) based on the following, where available, for each property. TCE Indoor Air Response Ranges (Government of South Australia, 2014) provide ranges of TCE indoor air concentrations that indicate that no action, validation, investigation, intervention or accelerated intervention is required for residential dwellings where these indoor air TCE concentrations are reported.


Least reliable Soil vapour data from depths greater than 0.85 mbgl (using the attenuation factors from source Golder, 2015f);

Soil vapour data from 0.85 mbgl (using the attenuation factors from Golder, 2015f);

Subslab vapour data (using the attenuation factors from Golder, 2015f);

Crawlspace data; and Most reliable

source Indoor air.

It is noted the reliance levels for the sources listed above are those provided by Golder (2015e).

The response levels based on the soil vapour data from 0.85 m and subslab vapour data with attenuation factors were found to be the same, or more conservative, than the response ranges based on the crawlspace and/or indoor air data.

Given no property specific data (ie crawlspace or indoor air sample results) was available for the majority of the properties within the Assessment Area, ‘residential zones’ were characterised as to their theoretical TCE Indoor Air Response Range based on soil vapour data from depths greater than 0.85 mbgl and depths of 0.85 mbgl. Table 2.1 summarises the number of properties estimated to be in each of the TCE Indoor Air Response Ranges (Government of South Australia, 2014).

Table 2.1: Summary of Number of Properties Within Each Response Range

Response Range Classification Response Range TCE Indoor Air Level (µg/m3) Estimated Number of Properties

No Action Nothing 43

Validation Less than 2 µg/m3 88

Investigation Between 2 and 20 µg/m3 16

Intervention Between 20 and 200 µg/m3 24

Accelerated Intervention Greater than 200 µg/m3 6

2.10 Conceptual Site Model

The Conceptual Site Model (CSM) report (Golder, 2015g) describes the setting, previous investigations, potential sources of TCE contamination, extent of contamination in groundwater and soil vapour, potential receptors and exposure pathways and data gaps. An updated CSM, which builds upon the Golder (2015g) CSM, is included within Section 10 of this report


3. Environmental Setting

3.1 Topography

The Assessment Area and Broadened Assessment Area is generally flat with an elevation of approximately 10 m relative to the Australian Height Datum (AHD) based on the Adelaide 1:25,000 Topographic Map.

The site is located approximately 2 km to the north of River Torrens, approximately 4 km south‐east of West Lakes, and approximately 4.95 km east of Gulf St Vincent.

3.2 Geology

The site is approximately 4 km west of the Para Fault. Review of the 1:250,000 ‘South Australia Geological Atlas Series – Adelaide, Sheet SI 54‐9, Zones 5 & 6’ geological map of the Adelaide Region indicates that the Assessment Area is underlain by the Pooraka Formation, which is underlain by Hindmarsh Clay. The Pooraka Formation consists of pale red‐brown sandy clay containing carbonate of the Loveday Soil. Lenses of coarser material are present within this formation. The Hindmarsh Clay consist of grey and red‐brown mottled sandy clay. Lenses of coarser material are also present within this formation.

Drilling works have identified generally shallow fill materials (gravelly or sandy clay) overlying silty / sandy clay. It is noted deeper fill materials (to a depth of approximately 6.1 mbgl) were encountered during the installation of one well.

There is evidence provided by EPA that some sites within the Assessment Area and Broadened Assessment Area may have been used as pugholes. It is noted that a groundwater well (MW17) was installed at a property identified previously as a potential pughole location. Fill materials were reported to extend to increased depth at this location (surface to approximately 6.1 mbgl), which supports the potential pughole location.

The aquifer of interest (the shallow aquifer) lies within a zone of Quaternary sediments which includes the Callabonna Clay, Pooraka Formations and Hindmarsh Clay. The Hindmarsh Clay contains up to six thin aquifers (classified as Q1‐Q6) comprised primarily of mottled clay and silt with thin interbedded layers of sand and gravel which form minor unconfined and semi confined systems. It is possible that all six Quaternary aquifer units are present beneath the EPA Assessment Area and Broadened Assessment Area.

3.3 Regional and Local Hydrogeology

The upper Quaternary Aquifer (Q1) was present in the form of a silty / sandy clay with trace sands at 6 ‐ 8.5 mbgl and a gravelly clay which ranged from 10 ‐ 15 mbgl. The Q1 and Q2 aquifer units are hydraulically separated by the Hindmarsh Clay aquitard which is comprised primarily of mottled red‐brown to orange clay and fluvial and alluvial red‐brown silty sandstone.

3.3.1 Water Level of the Q1 Aquifer

As part of the latest groundwater investigation works completed by JBSG in 2016, a total of 20 groundwater monitoring wells were gauged and sampled across the EPA Assessment Area and Broadened Assessment Area. Based on level data from the February 2016 gauging event, the shallow aquifer occurs at a depth between 7.0 m (MW14) and 9.0 mbgl (MW18). The shallow aquifer lithology is generally comprised of silty sandy clays with fine to coarse grained sand. The shallow Q1 aquifer is considered to be unconfined.

3.3.2 Groundwater Flow Direction of the Q1 Aquifer

Previous groundwater investigations carried out by URS in 2008 and Golder in 2015 have indicated that the groundwater flow direction is predominantly to the west towards the coast. Groundwater investigations carried out by JBS&G in February 2016 however indicated a more north‐westerly flow


direction. The discrepancy in flow directions is most likely due to hydrologic fluctuations such as seasonal and climatic variations affecting groundwater levels between gauging rounds. Historical reports have indicated variations in water level of up to 0.6 m observed in this area.

The westerly groundwater flow discharge is expected to occur at the coast which lies approximately 3 km from the Assessment Area. The north westerly groundwater flow discharge is expected to occur at West Lakes which occurs approximately 4 km north west of the Assessment Area. There are no other lakes or rivers in the vicinity of the site or between the site and the coast or West Lakes that could act as local groundwater sinks.

3.3.3 Hydraulic Gradient of the Q1 Aquifer

The westerly hydraulic gradient was calculated to be between 0.001 and 0.0003 m/m, with a slightly flatter gradient west of the site area (downhydraulic gradient) and a slightly steeper gradient to the east (uphydraulic gradient) of the site. The change in gradient is thought to be attributable to lithological changes in the aquifer that are reflected in the aquifer hydraulic conductivity.

3.3.4 Hydraulic Conductivity of the Q1 Aquifer

Rising head hydraulic conductivity testing (slug tests) were undertaken by Golder (2015a) in selected groundwater monitoring wells. The results of this testing are summarised in Table 3.1.

Table 3.1: Hydraulic Conductivity Data

Well Easting Northing Hydraulic Conductivity

m/day m/sec

MW02 275771.15 6136245.743 3.582 4.15 E‐05

MW05 275545.071 6136126.675 3.946 4.57 E‐05

MW06 275419.95 6136139.884 0.276 3.20 E‐06

MW07 275306.562 6136119.474 3.078 3.56 E‐05

XMW02 275771.15 6136245.743 0.501 5.80 E‐06

The maximum hydraulic conductivity value was estimated to be 3.9 m/day and the minimum was 0.3 m/day. Three of the five results were higher than 3 m /day and the remaining two results were around or less than 0.5 m/day. This range in values is expected to be due to the variation in lithologies existing within the aquifer which range from silty sands to sandy clays with variable gravel content. The mean of the results was 2.3 m/day and the geometric mean was 1.4 m/day.

3.3.5 Porosity of the Q1 Aquifer

The porosity and storage properties of the shallow aquifer have not been directly assessed at the site. The aquifer storage terms are not relevant for the steady state hydraulic model as the definition of steady state is that there is no change in the aquifer storage and so the storage terms can be ignored.

The effective porosity of the aquifer was estimated based on Domenico and Schwartz (1990). Domenico and Schwartz (1990) indicate a range for sandy clay materials from 0.03 to 0.2. The total porosity of a clayey material ranges from 0.34 to 0.6.

3.3.6 Recharge of the Q1 Aquifer

Groundwater recharge is expected to occur as a result of infiltration. The area is extensively developed with urban housing and associated infrastructure and so the potential for aquifer recharge in this setting may be relatively low.


‐ ‐ ‐ ‐ ‐

4. Chemicals of Interest

The chemicals of interest at the site are TCE and its breakdown products (ie cis‐1,2‐DCE, trans‐1,2‐DCE, 1,1‐DCE and VC). PCE is also a chemical of interest as it is often used as a solvent at sites where TCE is used.

The properties of the chemicals of interest (RAIS, 2016) are summarised in Table 4.1.

Table 4.1: Summary of the Properties of the Chemicals of Interest

Chemical Properties PCE TCE Cis 1,2 DCE Trans 1,2 DCE 1,1 DCE VC

Henry’s Law Constant at 25°C (‐) 0.724 0.403 0.67 0.383 1.07 1.14

Diffusivity in Air (cm2/s) 5.05*10‐2 6.87*10‐2 8.84*10‐2 8.76*10‐2 8.63*10‐2 0.107

Diffusivity in Water (cm2/s) 9.46*10‐6 1.02*10‐5 1.13*10‐5 1.12*10‐5 1.10*10‐5 1.20*10‐5

Water Solubility (mg/L) 206 1,280 6,410 4,520 2,420 8,800

Organic Carbon Partitioning Coefficient (L/kg)

94.9 60.7 39.6 39.6 31.8 21.7


5. Scope of Work

The following scope of work was undertaken in order to meet the objectives of the investigation:

Installation of 11 groundwater wells (MW08‐MW18) to a depth of 12 mbgl in January and February 2016;

Sampling of a total of 20 groundwater wells, including the 11 newly installed wells (MW08‐MW18) and 9 existing groundwater wells (XMW02, XMW03 and MW01‐07) in February 2016;

Installation of soil vapour probes at 15 locations in January and February 2016, including 10 nested locations where the probes were installed to depths of 2 and 4 mbgl (SV101‐SV106, SV108‐SV110 and SV112) and five single depth probes (SV107, SV111 and SV113‐SV115) which were installed to 2 mbgl;

Sampling of vapour at a total of 24 locations in February 2016, including the following:

‐ 10 newly installed nested locations to 2 and 4 mbgl (SV101‐SV106, SV108‐SV110 and SV112);

‐ Five newly installed single depth probes to 2 mbgl (SVP01‐SVP03);

‐ Four selected existing multi depth locations to depths between 1 and 6.5mbgl (SV06‐2m, SV06‐4m, SV06‐6.5m, SV07‐2m, SV07‐4m, SV19‐1m, SV19‐2m, SV19‐4m, SV20‐1m, SV20‐2m, SV20‐4m); and

‐ Five selected single depth locations to depths of 1 or 4 mbgl (SV05‐4m, SV11‐1m, SV16‐1m, SV17‐1m, SV18‐1m).

Laboratory analysis of each groundwater and soil vapour sample collected for the chemicals of interest, including chlorinated hydrocarbons;

Survey of each newly installed groundwater well (MW08‐MW18) and soil vapour probe (SV101‐SV115);

Update of the CSM;

Soil vapour fate and transport modelling to determine:

‐ Theoretical TCE Indoor Air Response Ranges for residential properties within the Broadened Assessment Area; and

‐ Site specific TCE groundwater concentrations for each of the TCE Indoor Air Response Range classifications; and

3D groundwater fate and transport modelling for the purpose of informing a potential groundwater prohibition area (GPA).


http:SV06-6.5m

6. Soil Investigation

6.1 Methodology

The following guidance documents were referenced as part of the soil assessment:

National Environmental Protection Council (1999 as amended 2013) National Environmental Protection (Assessment of Site Contamination) Measure (NEPM).

Standards Australia (2005) Guide to the Sampling and Investigation of Potentially Contaminated Soil Part 1: Non‐Volatile and Semi‐Volatile Compounds. AS4482.1‐2005.

Standards Australia (2005) Guide to the Sampling and Investigation of Potentially Contaminated Soil Part 2: Volatile Compounds. AS4482.2‐1999.

Soil sampling was undertaken during the installation of the groundwater wells and soil vapour probes, rather than as a standalone task. To this end, a detailed description of the groundwater well and soil vapour probe drilling program and associated QA/QC is included in Sections 7 and 8, while this section focuses primarily upon the soil sampling process. The soil sampling methodology undertaken during the installation of groundwater wells and soil vapour probes is summarised below in Table 6.1.

Table 6.1: Summary of Soil Sampling Methodology

Soil Samples Collected During Groundwater wells were drilled using a combination of hand auger (to clear Groundwater Well Installation the surface 1.5 m for services) and solid auger techniques. Samples were (27 January 2016 to 3 February 2016) initially collected at 1 m intervals, however, following discussion with the

EPA on 2 February 2016, samples were collected from the base of each groundwater well only.

Soil samples were placed directly into Teflon sealed glass jars provided by the laboratory, and then placed within a cool box containing ice. All samples had no headspace. Replicate soil samples were used to collect a Photo Ionisation Detector (PID) measurement.

Soil Samples Collected During Soil Vapour Probe Installation (20 to 27 January 2016)

Soil vapour probes were drilled using a combination of hand auger (to clear the surface 1.5 m for services) and pushtube techniques. Samples were initially collected throughout the soil profile at all soil vapour probe locations.

Soil samples were placed directly into Teflon sealed glass jars provided by the laboratory, and then placed within a cool box containing ice. All samples had no headspace. Replicate soil samples were used to collect a PID measurement.

Following review of the logs and field data, and discussion with the EPA, selected samples were analysed. The laboratory analytical schedule is summarised below in Table 6.2.


Table 6.2: Summary of Soil Analytical Schedule Location ID Soil Sample Depth (m) Moisture VOCs TRH pH

SV101 1.8‐2.0

3.8‐4.0

X

X X X

SV102 1.8‐2.0

3.8‐4.0

X

X

SV103 1.8‐2.0

3.8‐4.0

X

X

SV104 1.8‐2.0

3.8‐4.0

X

X

SV105 3.8‐4.0

1.8‐2.0

X

X

SV106 1.8‐2.0

3.8‐4.0

X

X

SV107 1.8‐2.0 X

SV108 3.8‐4.0

1.8‐2.0

X

X

SV109 1.9‐2.1

3.8‐4.0

X

X

SV110 1.8‐2.0

3.8‐4.0

X

X

SV111 1.9‐2.0 X

SV112 1.9‐2.1

3.8‐4.0

X

X

SV113 1.8‐2.0 X

SV114 1.8‐2.0 X X X

SV115 1.8‐2.0 X X X

MW08 11.8‐12.0 X X X X

MW09 11.8‐12.0 X X X X

MW10 11.8‐12.0 X X X X

MW11 11.8‐12.0 X X X X

MW12 11.8‐12.0 X X X X

MW13 12.0‐12.2 X X X X

MW14 11.8‐12.0 X X X X

MW15 11.8‐12.0 X X X X

MW16 11.8‐12.0 X X X X

MW17 12.8‐13.0 X X X X

MW18 12.8‐13.0 X X X X


6.2 Adopted Screening Levels

As stated above, soil sampling was undertaken during the installation of the groundwater wells and soil vapour probes as best practice, rather than as a standalone task for the purpose of assessing soils for the presence of the chemicals of interest.

Soil results were compared against the NEPM (NEPC, 1999 as amended 2013) groundwater Health Screening Levels (HSLs) for vapour intrusion. NEPM ‘A’ / ‘B’ for residential landuse, and also NEPM ‘D’ for commercial / industrial landuse. The HSLs also require soil type and sample depth – a soil type of ‘sand’ and NEPM sample depth categories 1m to

6.4.2.2 pH and Moisture

pH results ranged between 7.7 and 9.1 pH units, indicating the soils are neutral to slightly alkaline.

The soil moisture results for 2 and 4 mbgl (collected during the soil vapour probe installation) are summarised below in Table 6.3.

Table 6.3: Summary of Soil Moisture Results for 2 and 4 mbgl Samples

Sample Depth (mbgl) Soil Moisture Content (%)

Minimum Maximum Mean

2 mbgl 11 21 15.67

4 mbgl 14 20 16.5


7. Groundwater Investigation

7.1 Methodology

All groundwater works were undertaken in accordance with the methodologies outlined in the following guidance documents:

National Environmental Protection Council (1999 as amended 2013) NEPM.

Environment Protection Authority South Australia (2007) Regulatory monitoring and testing ‐Groundwater sampling.

Australian / New Zealand Standard (1998a) Water quality – Sampling, Part 1: Guidance on the design of sampling programs, sampling techniques and the preservation and handling of samples. AS/NZS 5667.1.

Australian / New Zealand Standard (1998b) Water quality – Sampling, Part 11: Guidance on sampling of groundwaters. AS/NZS 5667.11.

7.1.1 Groundwater Well Installation

11 groundwater wells (MW08‐MW18) targeting the shallow aquifer were installed between 27 January 2016 and 3 February 2016. The following installation methodology was undertaken:

Well permits were obtained from obtained from the Department of Environment, Water and Natural Resources (DEWNR). Well permits are included in Appendix D.

The locations of the groundwater monitoring wells were marked and cleared by a professional underground service locator following review of dial before you dig plans.

Downhole drilling equipment was decontaminated prior to the commencement of drilling at each investigation location to minimise the potential for cross contamination. Rinsate samples were collected to validate decontamination techniques on all days of drilling.

Ten groundwater wells (MW08‐MW16 and MW18) were installed to a depth of approximately 12 mbgl, while one groundwater well (MW17) was installed to a depth of approximately 13 mbgl (this location was slightly elevated compared to the broader area). All groundwater wells were installed using solid auger methods (after surface clearance using a hand auger) by a licensed driller.

The soils encountered were logged in accordance with the Unified Soil Classification System (USCS) by an experienced environmental scientist. Soil logs are included in Appendix E. Photographs of the soils encountered are included in Appendix F. Soil samples were collected throughout the soil profile at 0.5 m intervals for groundwater wells installed between 27 January 2016 and 1 February 2016. Following a discussion with the EPA on 2 February 2016, soil samples were collected from the base of each groundwater well only. Replicate soil samples were screened in the field for potential volatile contaminants using a PID. The PID was calibrated using isobutylene to 100 ppm prior to use. The PID detects all chemicals with an ionization energy less than or equal to the lamp output (10.6 eV in this case). It is noted all chemicals of interest have ionization energy less than 10.6 eV. The PID calibration records are retained on the JBS&G calibration register.

Excess soil cuttings were placed in drums on portable bunds on the designated storage site, and classified for offsite disposal. All drums were disposed at completion of the drilling program. Receipts from the licenced contractor are provided in Appendix G.

The groundwater wells were constructed using 50 mm Class 18 uPVC screen and casing (pressure rated to conform to AS1477). The National Water Commission’s ‘Minimum Construction Requirements for Water Bores in Australia’ (February 2012) recommends Class


12 is used for most bore construction applications, with Class 9 suitable for some shallow bores. Class 18 as used in construction of wells at the site is considered suitable. The uPVC screen and casing pipe had machine cut threads with rubber o‐rings to ensure a tight seal between casing lengths and to avoid the use of glues / lubricants in constructing the well. The uPVC is inert and compatible with the chemicals of interest. A screen length of 6 m was installed in each groundwater well.

A graded sand pack was installed from the bottom of the drilled borehole to approximately 0.5 m above the screened interval. A bentonite seal of a minimum of 0.5 m was installed above the sand layer. The well was completed to the surface with cement / bentonite grout and was finished at the surface with a flush mounted gatic cover concreted into the surface. A lockable end cap was fitted over the top of the well (beneath the gatic cover) to prevent any ingress of water to the well.

All newly installed groundwater wells were developed following installation to ensure adequate hydraulic connection with the aquifer using low density polyethylene (LDPE) tubing and a high flow pump. The development of the wells will consist of purging the wells dry at least four times, or purging eight casing volumes, with greater volumes purged if fine sand / silt / clay is still evident or field parameters have not stabilised (three consecutive bore volumes) within the ranges presented within the SA EPA ‘Regulatory Monitoring and Testing: Groundwater Sampling’ guideline (2007). Development sheets for all newly installed groundwater wells are included in Appendix H.

All newly installed groundwater wells were surveyed by a professional and licensed surveyor. The survey data is included in Appendix I.

Well construction details and the log of the soils encountered are included in Appendix E. The construction details are summarised below in Table 7.1.

Table 7.1: Groundwater Monitoring Well Construction Details

Well ID Date Installed Installed depth Screened Interval SWL

Mbgl mbgl mTOC

MW08 2‐Feb‐16 12.0 6.0 to 12.0 8.792

MW09 2‐Feb‐16 12.0 6.0 to 12.0 8.464

MW10 28‐Jan‐16 12.0 6.0 to 12.0 7.706

MW11 2‐Feb‐16 12.0 6.0 to 12.0 7.553

MW12 29‐Jan‐16 12.0 6.0 to 12.0 6.909

MW13 27‐Jan‐16 12.5 6.5 to 12.5 7.057

MW14 29‐Jan‐16 12.0 6.0 to 12.0 6.776

MW15 28‐Jan‐16 12.0 6.0 to 12.0 7.016

MW16 3‐Feb‐16 12.0 6.0 to 12.0 7.788

MW17 1‐Feb‐16 13.0 7.0 to 13.0 8.878

MW18 3‐Feb‐16 12.0 6.0 to 12.0 9.035

The locations of the groundwater wells are shown in Figure 2.


&

&

EPA Assessment Area Legend:

Broadened EPA Assessment Area Groundwater Monitoring Well < Existing < Installed February 2016

Job No: 51350 Client: SA EPA Version: FINAL Date: 18-Apr-2016 Drawn By: AS Checked By: KC

ZScale at A4 1:5,500 0 75 150

metres

Coor. Sys. GDA 1994 MGA Zone 54 Stage 3 Beverley Broadened EPAAssessment Area, Beverley, South Australia GROUNDWATER WELL LOCATION PLAN

FIGURE 2 Document Path: W:\Projects JBSG Australia\Adelaide\51350_SA EPA_ Beverley_Stage 3\ArcGIS\Maps\Groundwater Investigation Location Plan.mxd Image Reference: www.nearmap.com© - Imagery Date: 6 February 2016

&<

&<

&<

&< &<

&<

&<

&<

&<

&< &<

&< &<

&<

&<

&<

&<

&<

&<

&<

MW07 MW06 MW05

MW04 MW03 MW02 MW01

XMW03

XMW02 MW18 MW17

MW16

MW15 MW14

MW13

MW12

MW11 MW10 MW09 MW08

http:www.nearmap.com

7.1.2 Groundwater Sampling

Documents

FINAL REPORT EPAReference · FINAL REPORT EnvironmentalProtection Authority South Australia Stage3 Beverley Assessment Works. EPAReference: 05/22106. 26April 2016 51350_RP02_Rev2