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GLENELG EAST EPA ASSESSMENT AREA STAGE 3 ENVIRONMENTAL ASSESSMENT

FINAL REPORT | EPA REF 05/21777

ENVIRONMENT PROTECTION AUTHORITY, SOUTH AUSTRALIA

8 APRIL 2016

VOLUME 1: REPORT AND VOLUME 2 APPENDICES

GLENELG EAST EPA ASSESSMENT AREA

STAGE 3 ENVIRONMENTAL ASSESSMENT

FINAL REPORT

EPA REF 05/21777

PREPARED FOR Environment Protection Authority, South Australia

PREPARED BY Fyfe Pty Ltd

ABN 57 008 116 130

ADDRESS L3, 80 Flinders Street, Adelaide SA 5000

CONTACT Mr Marc Andrews, Division Manager - Environment

TELEPHONE direct 08 8201 9794 mobile 0408 805 264

FACSIMILE 61 8 8201 9650

EMAIL [email protected]

DATE 8/04/2016

REFERENCE 80445-1 REV1

Fyfe Pty Ltd, 2016

Proprietary Information Statement

The information contained in this document produced by Fyfe Pty Ltd is solely for the use of the Client identified on the cover sheet for the purpose for which it has been prepared and Fyfe Pty Ltd undertakes no duty to or accepts any responsibility to any third party who may rely upon this document.

All rights reserved. No section or element of this document may be removed from this document, reproduced, electronically stored or transmitted in any form without the written permission of Fyfe Pty Ltd.

Document Information

Report prepared by: Dr Ruth Keogh Principal Environmental Scientist, Fyfe Pty Ltd Date: 8 April 2016

VIRA prepared by: Dr Sim Ooi Principal, Salcor Consulting Date: 23 March 2016

Report reviewed and approved by: Marc Andrews

Division Manager - Environment, Fyfe Pty Ltd Date: 8 April 2016

Client receipt by: Dale McGill Advisor, Site Contamination, SA EPA Date: 8 April 2016

Revision History

Revision Revision Status

REV 0 Draft

REV 1 Final

Date

24 March 2016

8 April 2016

Prepared

RK

RK

Reviewed

MJA

MJA

Approved

MJA

MJA

EPA REF 05/21777 FINAL REPORT

STAGE 3 ENVIRONMENTAL ASSESSMENT GLENELG EAST EPA ASSESSMENT AREA

CONTENTS

Page

VOLUME 1: REPORT

LIST OF ACRONYMS vi

EXECUTIVE SUMMARY ix

1. INTRODUCTION 1

1.1 Purpose 1

1.2 General background information 1

1.3 Definition of the assessment area 2

1.4 Identification of contaminants of potential concern 2

1.5 Objectives 2

2. CHARACTERISATION OF THE ASSESSMENT AREA 3

2.1 Site identification 3

2.2 Regional geology and hydrogeology 3

2.3 Data quality objectives 5

3. SCOPE OF WORK 8

3.1 Preliminary work 8

3.2 Field investigation and laboratory analysis program 8

3.3 Data interpretation 11

4. METHODOLOGY 12

4.1 Laboratory analysis 16

5. QUALITY ASSURANCE AND QUALITY CONTROL 17

5.1 Field QA/QC 17

5.2 Laboratory QA/QC 21

5.3 QA/QC summary 22

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6. RESULTS 23

6.1 Surface and sub surface soil conditions 23

6.2 Soil field results 23

6.3 Soil moisture results 23

6.4 Soil geotechnical testing results 24

6.5 Soil vapour analytical results 25

6.6 Air sampling results 26

6.7 Subsurface utility access point survey results 27

6.8 Groundwater field measurements 27

6.9 Groundwater analytical results 29

7. RESIDENTIAL SURVEY 36

8. GROUNDWATER FATE AND TRANSPORT MODELLING 37

9. VAPOUR INTRUSION RISK ASSESSMENT 39

9.1 Objective 39

9.2 Areas of interest 39

9.3 Risk assessment approach 39

9.4 Tier 1 assessment 40

9.5 Tier 2 assessment 43

10. CONCEPTUAL SITE MODEL 53

11. CONCLUSIONS 59

12. RECOMMENDATIONS 62

13. REFERENCES 63

14. STATEMENT OF LIMITATIONS 67

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LIST OF TABLES

Table 2.1 Information regarding registered groundwater bores located within the GE EPA Assessment

Area 4

Table 2.2 Data Quality Objectives 6

Table 3.1 Scope of field investigation program 8

Table 3.2 Scope of laboratory testing program 10

Table 4.1 Summary of field methodologies 12

Table 5.1 Field QA/QC procedures - Soil 18

Table 5.2 Field QA/QC procedures - Groundwater 19

Table 5.3 Field QA/QC procedures Soil vapour 20 Table 5.4 Field QA/QC procedures Crawl space, indoor and outdoor air sampling 21 Table 5.5 Laboratory QA/QC procedures 22

Table 6.1 Laboratory soil moisture results 24

Table 6.2 Highest soil vapour bore CHC results for GE EPA Assessment Area 25

Table 6.3 Hydraulic conductivities (rising head tests) 29

Table 6.4 Assessment of groundwater beneficial uses 31

Table 6.5 Sources of adopted groundwater assessment criteria 31

Table 6.6 AS2159-2009 groundwater exposure classifications for concrete and steel piles 32

Table 8.1 Aquifer hydrogeological properties 37

Table 9.1 Soil parameters adopted for vapour intrusion modelling 45

Table 9.2 Vapour intrusion model assumptions of a residential building with slab-on-ground 46

Table 9.3 Vapour intrusion model assumptions of a residential building with crawl space 47

Table 10.1 Summary of existing information for the GE EPA Assessment Area 53

LIST OF FIGURES (in text)

Figure 6.1 Piper Diagram 34

Figure 9.1 TCE indoor air screening criteria and the corresponding site-specific response levels 44

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FIGURES (following page 67)

Figure 1: Site Location and Assessment Area

Figure 2: Assessment Point Locations

Figure 2A: Assessment Point Locations Zoom

Figure 3: Groundwater Elevation Contour Plan

Figure 4: Groundwater PCE Concentration Plan

Figure 5: Groundwater TCE Concentration Plan

Figure 6: Soil Vapour PCE Concentration Plan 1.5 m

Figure 7: Soil Vapour TCE Concentration Plan 1.5 m

Figure 8: Predicted TCE Indoor Air Concentrations (Modelled)

Figure 9: Geological Cross Section Assessment Area

VOLUME 2: APPENDICES

APPENDICES

Appendix A Historical Report Summary

Appendix B DEWNR Registered Groundwater Database Search Results

Appendix C Groundwater well Permits

Appendix D Anemometer Data

Appendix E Survey Data

Appendix F Field Sampling Sheets Soil Vapour Appendix G Field Sampling Sheets - Groundwater

Appendix H Soil Vapour Borehole Log Reports

Appendix I Groundwater Well Log Reports

Appendix J Drill Core Photographs

Appendix K Tabulated Results Soil Vapour, Geotechnical, Air and Groundwater Appendix L Equipment Calibration Records

Appendix M Certified Laboratory Certificates and Chain of Custody Documentation

Appendix N Subsurface Utility Assessment Results

Appendix O Aquifer Permeability (Slug) Test Results

Appendix P Arcadis Groundwater Fate and Transport Modelling Report

Appendix Q Assessment of Crawl Space Attenuation Factor

Appendix R Tier 1 Assessment Soil Vapour, Source Site (Commercial/Industrial) Appendix S Tier 1 Assessment Soil Vapour, Residential Zone Appendix T Tier 1 Assessment Crawl Space and Indoor Air, Residential Zone Appendix U Vapour Intrusion Model Soil Moisture and Geotechnical Data Appendix V Vapour Intrusion Model Soil Vapour, Residential Slab-on-Ground Appendix W Vapour Intrusion Model Soil Vapour, Residential Crawl Space Appendix X Vapour Intrusion Model Soil Vapour, Commercial/Industrial Slab-on-Ground Appendix Y Comparison of Attenuation Factors (Slab-on-Ground versus Crawl Space)

Appendix Z Tier 2 Assessment Soil Vapour, Residential Slab-on-Ground

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Appendix AA Tier 2 Assessment Soil Vapour, Source Site (Commercial/Industrial) Slab-on-Ground Appendix BB Vapour Intrusion Model Groundwater, Residential Slab-on-Ground Appendix CC Vapour Intrusion Model Groundwater, Residential Basement Appendix DD Vapour Intrusion Model Groundwater, Commercial/Industrial Slab-on-Ground Appendix EE Tier 2 Assessment Groundwater, Residential Slab-on-Ground Appendix FF Tier 2 Assessment Groundwater, Residential Basement Appendix GG Tier 2 Assessment Groundwater, Source Site (Commercial/Industrial) Slab-on-Ground Appendix HH Tier 2 Assessment Soil Vapour, Residential Basement

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LIST OF ACRONYMS

ACH Air Exchange per Hour

AHD Australian Height Datum

ALS Australian Laboratory Services

ANZECC Australian and New Zealand Environment and Conservation Council

ARMCANZ Agriculture and Resource Management Council of Australia and New Zealand

AST Aboveground Storage Tank

ASTM American Standard Testing Material

BGL Below Ground Level

BTEX Benzene, Toluene, Ethylbenzene, Xylenes

BTOC Below Top of Casing

BUA Beneficial Use Assessment

CCME Canadian Council of Ministers of the Environment

CHC Chlorinated Hydrocarbon Compound

COC Chain of Custody

COPC Contaminants of Potential Concern

CSM Conceptual Site Model

1,1-DCA 1,1-dichloroethane

1,1-DCE 1,1-dichloroethene

1,2-DCE 1,2-dichloroethene

DCE Dichloroethene

DEWNR Department of Environment, Water and Natural Resources

DNAPL Dense Non-Aqueous Phase Liquid

DO Dissolved Oxygen

DQO Data Quality Objective

EC Electrical Conductivity

EIL Ecological Investigation Level

EPA Environment Protection Authority

ESA Environmental Site Assessment

GDA Geocentric Datum of Australia

GE Glenelg East

GIL Groundwater Investigation Level

GME Groundwater Monitoring Event

GPA Groundwater Prohibition Area

GPR Ground Penetrating Radar

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HIL Health Investigation Level

HSP Health and safety Plan

IPA Isopropyl Alcohol (isopropanol or 2-propanol)

ITRC Interstate Technology and Regulatory Council

J&E Johnson and Ettinger

JHA Job Hazard Analysis

KGS Kansas Geological Survey

MEK Methyl Ethyl Ketone

MQO Measuring Quality Objectives

NAPL Non-Aqueous Phase Liquid

NATA National Association of Testing Authorities

ND Non Detect

NEPM National Environment Protection Measure

NHMRC National Health and Medical Research Council

NJDEP New Jersey Department of Environmental Protection

NRMMC National Resource Management Ministerial Council

PAH Polycyclic Aromatic Hydrocarbons

PCE Tetrachloroethene

PID Photoionisation Detector

PQL Practical Quantification Limit

PSD Particle Size Distribution

QA Quality Assurance

QC Quality Control

RAIS Risk Assessment Information System

RFQ Request for Quote

RPD Relative Percentage Difference

SA EPA South Australian Environment Protection Authority

SAQP Sampling and Analysis Quality Plan

SWL Standing Water Level

SWMS Safe Work Method Statement

TCE Trichloroethene

TDS Total Dissolved Solids

TRH Total Recoverable Hydrocarbons1

TRV Toxicity Reference Value

TRH = TPH (measurable amount of petroleum-based hydrocarbon = complex mixture of crude oil and natural gas (> 250 compounds), including aromatics, aliphatics, paraffins, unsaturated alkanes and naphthalenes) plus various other compounds, including fatty acids, esters, humic acids, phthalates and sterols.

80445-1 REV1 8/04/2016 PAGE VII

1



US EPA United Stated Environment Protection Agency

UST Underground Storage Tank

VC Vinyl Chloride

VIRA Vapour Intrusion Risk Assessment

VOC Volatile Organic Compound

WHO World Health Organisation

80445-1 REV1 8/04/2016 PAGE VIII



EXECUTIVE SUMMARY

Background information

An approximate 34 hectare mixed use area of Glenelg East has been designated by the South Australian

Environment Protection Authority (EPA) as the GE EPA Assessment Area.

Previous environmental assessment work undertaken since 2002 has identified the site located at 37-41 Cliff

Street as a source of dissolved phase groundwater chlorinated hydrocarbon (CHC) contamination. The

source site is reported to have been occupied by a dry cleaning facility (Glenelg Dry Cleaners) from the

1940s-1950s until about 2006 and to have hosted a factory building and spirit store as well as various

aboveground and underground tanks used for the storage of tetrachloroethene (PCE) and petroleum

hydrocarbons (i.e. petrol and diesel). Site assessment work identified the presence of PCE as well as its

break-down products, trichloroethene (TCE) and dichloroethene (DCE), within site soils and the uppermost

(shallow) groundwater aquifer beneath the site. Groundwater impacts were found to extend off-site in a

general west to north-westerly direction and to have resulted in the generation of soil vapour containing

elevated concentrations of CHC.

The boundaries of the GE EPA Assessment Area were established on the basis of the following:

the previous identification of soil, soil vapour and/or groundwater CHC contamination associated with

the site located at 37-41 Cliff Street in Glenelg East (i.e. the source site);

the identification of an inferred (general) north-westerly groundwater flow direction within the

uppermost aquifer; and

the previous identification of soil, soil vapour, groundwater and/or indoor air concentrations of CHC on

the site and/or extending off-site to the west and north-west that were considered to be of potential

concern with respect to human health.

Aim of Fyfe investigations

The results of the recent investigations have been used to assess potential vapour intrusion to indoor air

risks within residential and commercial/industrial properties within the GE EPA Assessment Area. The

specific aims detailed by the EPA were as follows:

to delineate the extent of the groundwater chlorinated hydrocarbon contamination;

to delineate the extent of the soil vapour chlorinated hydrocarbon contamination; and

to identify any potential vapour intrusion risks at properties within the GE EPA Assessment Area,

including consideration of slab, crawl space and sub-surface structures.

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Site conditions

Subsurface geological conditions are generally consistent across the GE EPA Soil Assessment Area and are dominated by the clays/silty clays and silty/clayey sands of

the Hindmarsh Clay formation. While there is some potential for structural defects and

sandier horizons to act as preferential pathways (lateral and vertical) for soil vapour

movement, no significant features were identified during the recent soil

drilling/logging work (i.e. with the exception of the silty/clayey sand layer at the depth

of the water table in some of the groundwater wells).

Groundwater within the uppermost (Quaternary) aquifer is located at a depth of Groundwater approximately 2.9 to 4.3 m BGL and flows in a general north-westerly direction the closest surface water receptor is the Gulf St Vincent, located approximately 1.65 km to

the west. A groundwater flow velocity of 26 m/year has been calculated and the

groundwater gradient beneath the GE EPA Assessment area is 0.0026 (i.e. relatively flat).

Beneficial uses for groundwater within the uppermost aquifer beneath the GE EPA

Assessment Area have been identified to include irrigation, primary contact

recreation/aesthetics, human health in non-use scenarios (i.e. vapour flux) and

possibly also contact with deep subsurface infrastructure.

Contaminants of Potential Concern (COPC)

Contaminants of potential concern, as identified by the EPA, include the following CHC: trichloroethene

(TCE), tetrachloroethene (PCE), 1,2-dichloroethene (1,2-DCE: cis- and trans-) and vinyl chloride (VC).

Concentrations of 1,1-dichloroetrhene (1,1-DCE) and 1, 1-dichloroethance (1,1-DCA) were also assessed.

These COPC were confirmed by the Fyfe investigations, with PCE identified as both the primary contaminant

(i.e. from the historical dry cleaning operations) and the main contaminant (in terms of concentration and

extent) in groundwater beneath the GE EPA Assessment Area. By comparison, TCE was identified as a break

down product of PCE and the main driver in terms of potential human health risks (i.e. based on its toxicity)

associated with vapour intrusion into indoor air and was therefore used as a surrogate chemical for the

remaining COPC.

Scope of work

A groundwater, soil vapour and air monitoring program was undertaken across the GE EPA Assessment Area

between November 2015 and January 2016. It involved the following scope of work:

drilling and installation of nine soil vapour bores to 1.5 m below ground level (BGL);

drilling and installation of eight groundwater wells to depths of between 5.5 and 6.5 m BGL;

sampling of the newly installed soil vapour bores, as well as 20 existing bores (installed to 1.5 m BGL

with the exception of seven nested bores installed to depths of either 0.5 and 2.0 m BGL or 1.5 and 2.5

m BGL), for COPC and/or general gas analysis;

gauging and sampling of the newly installed groundwater wells as well as 24 existing monitoring wells

and seven private bores for CHC, with selected wells also tested for natural attenuation parameters,

major cations/anions and selected metals;

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aquifer permeability (rising head slug) testing of the newly installed groundwater wells and two

existing monitoring wells;

crawl space and indoor air sampling of the residence located at 35 Cliff Street (i.e. to the immediate

west of the source site);

outdoor (ambient) air sampling at the source site;

collection of soil samples for geotechnical analysis;

survey of potential vapour accumulation within subsurface utility access points along Cliff Street; and

a door-knock/survey of residences within a portion of the GE EPA Assessment Area.

The soil vapour and groundwater data were used to undertake a Vapour Intrusion Risk Assessment (VIRA)

aimed at predicting indoor air concentrations of TCE under various land use and building construction

scenarios.

Groundwater fate and transport modelling was undertaken to provide a preliminary estimate of the future

extent of CHC impacted groundwater within the GE EPA Assessment Area and to provide information to

support the definition (extent and geometry) of a Groundwater Prohibition Area (GPA), including a buffer

zone, to be designated by the EPA in accordance with the provisions of Section S103S of the Environment

Protection Act 1993.

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Identified impacts

Contaminants identified in groundwater beneath parts of the GE EPA Assessment AreaGroundwater include PCE, TCE, 1,2-DCE and trace 1,1-DCE; VC was not detected in any of the

groundwater wells tested. Measured TCE and 1,2-DCE levels in some wells exceeded

the adopted assessment criteria for primary contact recreation, thereby indicating that

groundwater would be unsuitable for the filling of swimming pools. In addition, vapour

flux could also occur during the extraction of groundwater for domestic use and, in

terms of aesthetic considerations, the groundwater could be odorous.

The groundwater CHC plume is considered to have migrated in a north-westerly

direction from 37-41 Cliff Street (source site), in accordance with the predominant

flow direction associated with the uppermost aquifer. The plume has been traced as

far west as Williams Avenue within the GE EPA Assessment Area (i.e. the most

westerly of the newly installed Fyfe wells) but its western extent has not yet been

determined.

Additional analytes assessed during the recent groundwater monitoring program

(including metals and nutrients) indicate that the groundwater is also likely to be

generally unsuitable for irrigation purposes in some parts (at least) of the GE EPA

Assessment Area.

Contaminants identified in soil vapour beneath parts of the GE EPA Assessment AreaSoil vapour include PCE, TCE, 1,2-DCE, VC, 1,1-DCE and 1,1-DCA.

Whereas the CHC contamination at the source site is considered to be a product of

both groundwater and soil contamination, the off-site distribution of PCE and TCE in

soil vapour at both 1.5 m and 2.5 m BGL generally correlates with the north-westerly

groundwater flow direction and is therefore considered to be a product of

volatilisation from the groundwater CHC plume.

The current extent of the soil vapour CHC (PCE and TCE) impacts has been determined

to extend beneath residential properties as far as Williams Avenue (i.e. the most

westerly of the soil vapour bores located within the GE EPA Assessment Area). The

western extent of the soil vapour CHC impacts has not been delineated.

The survey of subsurface utility access points along Cliff Street did not identify the

presence of any significant concentrations of CHC vapours.

Crawl space, indoor air and outdoor air monitoring results obtained for the residence Air (crawl space, at 35 Cliff Street identified detectable (but low) concentrations of TCE and PCE. The indoor and measured indoor air results correlated with predicted indoor air concentrations outdoor) determined by the VIRA.

Assessment of risk:

Groundwater fate The presence of PCE daughter products, including TCE and 1,2-DCE (mainly cis-), within

and transport the uppermost aquifer beneath the GE EPA Assessment Area is considered to be modelling

indicative of PCE breakdown occurring through the process of reductive

dechlorination.

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Vapour intrusion

risks

Groundwater fate and transport modelling has indicated that, although the

groundwater dissolved phase PCE plume may extend beyond its currently mapped

distribution (i.e. possibly to, or just beyond, the western boundary of the GE EPA

Assessment Area), both the PCE and TCE plumes are considered to be contracting

spatially and decreasing in concentration at individual locations, and are likely to

continue to do so in the future.

Although PCE and TCE were also detected within private bores located in the vicinity of

a service station on the corner of Brighton Road and Diagonal Road (i.e. external to the

GE EPA Assessment Area), the concentrations of PCE are substantially greater than in

the westernmost well within the Assessment Area and are thereby considered

indicative of a separate source.

The VIRA involved a two-tier assessment approach. Whereas the Tier 1 screening risk

assessment compared the measured soil vapour TCE concentrations to an adopted

guideline value, the Tier 2 risk assessment involved the application of the US EPA

(2004) Johnson and Ettinger vapour intrusion model to predict indoor air TCE

concentrations for residences (of both slab-on-ground and crawl space construction)

across the GE EPA Assessment Area. Site-specific geophysical parameters and soil

vapour data collected from 1.5 and 2.5 m BGL throughout the GE EPA Assessment

Area were used in the modelling.

The results of the Tier 2 risk assessment were used to infer concentration contours

between the soil vapour sampling locations. The predicted indoor air TCE

concentrations were assessed against the adopted indoor air criteria or response

levels developed by the EPA and SA Health.

The results for predicted indoor air concentrations of TCE within the residential

portion of the GE EPA Assessment Area indicated that 45 residential properties

corresponded to the >non-detect (i.e. 0.1 g/m3) to



monitoring the behaviour of the PCE and TCE plumes;

confirming the results of the groundwater fate and transport modelling.

validation of the soil vapour concentrations that have resulted in 45 residential properties located

within the GE EPA Assessment Area to be currently estimated as having predicted indoor air TCE

concentrations that correspond to the EPA >non-detect to



1. INTRODUCTION

1.1 Purpose

Fyfe Pty Ltd (Fyfe) was commissioned by the South Australian Environment Protection Authority (SA EPA,

referred to herein as the EPA) to undertake Stage 3 groundwater, soil vapour and air (indoor, outdoor and

residential crawl space) assessment works, as well as human health vapour intrusion risk assessment and

groundwater fate and transport modelling, within an EPA designated assessment area located within Glenelg

East, South Australia (herein referred to as the GE EPA Assessment Area). The location and extent of the GE

EPA Assessment Area referenced within this document is identified on Figure 1.

1.2 General background information

Previous environmental assessment work undertaken within the GE EPA Assessment Area since 2002, as

summarised in Appendix A, identified the site located at 37-41 Cliff Street as a source of dissolved phase

groundwater chlorinated hydrocarbon (CHC) contamination2. The source site is reported to have been

occupied by a dry cleaning facility (Glenelg Dry Cleaners) from the 1940s-1950s until about 2006 and to have

hosted a factory building and spirit store as well as various aboveground and underground tanks used for the

storage of tetrachloroethene (PCE) and petroleum hydrocarbons (i.e. petrol and diesel). Site assessment

work identified the presence of PCE as well as its break-down products, trichloroethene (TCE) and

dichloroethene (DCE), within site soils and the uppermost (shallow) groundwater aquifer beneath the site.

Groundwater impacts3

were found to extend off-site in a general west to north-westerly direction and to

have resulted in the generation of soil vapour containing elevated concentrations of CHC.

This latest assessment work was initiated by the EPA since the extent of the groundwater plume and its

potential associated risks to human health and/or the environment had not yet been fully established. The

main objective of this work was to assess and better characterise the potential human health risk posed by

vapour intrusion emanating from the groundwater CHC impacts.

2 Site Contamination is defined by the Environment Protection Act 1993 as existing if chemical substances are present on or below the surface of a site in concentrations above background, the contaminants are there as a result of activity at the site, or elsewhere, and their presence has resulted in actual or potential harm (that is not trivial) to the health and safety of human beings, taking into account current and proposed land uses, or water or the environment.

3 Note that the term impact has been used by Fyfe to indicate identified concentrations of compounds (specifically chlorinated hydrocarbons) that are not naturally occurring (i.e. concentrations above background that have resulted from anthropogenic activities). The use of this term does not denote that the presence of these compounds represents a risk to either human health or the environment and the term impact is therefore not directly interchangeable with the term Site ontamination, the latter defined under the Environment Protection Act 1993 to include actual or potential harm to human health and/or the environment.

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1.3 Definition of the assessment area

As detailed on Figure 1, the current EPA Assessment Area covers an area of approximately 34 ha within the

Glenelg East area.

The boundaries of the GE EPA Assessment Area were established by the EPA on the basis of the following:

the previous identification of soil, soil vapour and/or groundwater CHC contamination associated with

the site located at 37-41 Cliff Street in Glenelg East (i.e. the source site);

the identification of an inferred (general) north-westerly groundwater flow direction within the

uppermost aquifer; and

the previous identification of soil, soil vapour, groundwater and/or indoor air concentrations of CHC on

the site and/or extending off-site to the west and north-west that were considered to be of potential

concern with respect to human health.

1.4 Identification of contaminants of potential concern

The contaminants of potential concern (COPC) for the Assessment Area comprise a number of chlorinated

hydrocarbon compounds (CHC). The main COPC identified to date are tetrachloroethene (PCE) and

trichloroethene (TCE), both of which were used as solvents in dry cleaning businesses although TCE can also

occur as a break-down product of PCE. Additional COPC identified for the assessment area include the

breakdown products of PCE and TCE, namely 1,2-dichloroethene (1,2-DCE: cis- and trans-) and vinyl chloride (VC).

1.5 Objectives

The key objectives of the recent Stage 3 environmental assessment program are as follows:

to delineate the extent of the groundwater chlorinated hydrocarbon contamination;

to delineate the extent of the soil vapour chlorinated hydrocarbon contamination; and

to identify any potential vapour intrusion risks at properties within the GE EPA Assessment Area (refer

to Figure 1), including consideration of slab, crawl space and sub-surface structures.

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2. CHARACTERISATION OF THE ASSESSMENT AREA

2.1 Site identification

For the purpose of this investigation program, the GE EPA Assessment Area (as delineated in Figure 1) has

been defined by the following roadways:

North: portions of Rugless Terrace, Farr Terrace and Allen Terrace;

South: portions of Kipling Avenue and Meredith Avenue;

East: portions of Watt Street, Buttrose Street and Marryat Street, with part of the eastern boundary

defined by a line that transects the residential areas between Wilson Terrace and Meredith Avenue; and

West: portions of Conrad Street, Diagonal Road and Brighton Road.

2.2 Regional geology and hydrogeology

Information regarding regional geological and hydrogeological conditions has been sourced from Selby and

Lindsay (1982), Belpario and Rice (1989), the South Australian Department of Mines and Energy (1969, 1992)

and Green et al. (2010).

2.2.1 Geology

The Glenelg East area lies within the Golden Grove - Adelaide Embayment area of the St. Vincent Basin, which

consists of a succession of Tertiary and Quaternary age sediments. The sediments were first deposited in

swamps and from streams draining from the highlands, followed by various cycles of marine deposition which

occurred as the ocean advanced and retreated over the land surface.

Tectonic activity during the late Tertiary and early Quaternary periods resulted in variations within the

thickness of the strata, with uplifting (mountain building) and subsequent erosion resulting in the deposition

of riverine sediments, including sands and gravels, which were subsequently overlain by a thick sequence of

alluvial clays with lenses of sand and gravel. These units deposited within the Tertiary and Quaternary times

have formed a series of aquifers and confining layers (aquitards). The recent geological evolution of the area

has largely been controlled by global sea level fluctuations.

The natural soils within the Glenelg East area are typified by the Quaternary age soils and sediments of the

Adelaide Plains, which may include Callabonna Clay, Keswick Clay, Pooraka Formation and Hindmarsh Clay. Of

these, the dominant unit has been interpreted to comprise Hindmarsh Clay. This represents the basal unit of

the Adelaide Plains soils and sediments and has a maximum general thickness of more than 100 m. It

generally comprises a basal gravel layer, a middle layer of mottled red-brown to orange clay and an upper

layer of fluvial and alluvial red-brown silty sand. With the Glenelg East area, the Adelaide Plains sediments

may be overlain by grey fluviatile silts, sands and gravels of modern drainage channels.

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The Quaternary age sediments of the Adelaide Plains are underlain, in sequence, by a succession of Tertiary

age sediments, including the Hallett Cove Sandstone, Port Willunga Formation and South Maslin Sands. These

sedimentary units are in turn underlain by metamorphosed basement rock of the Proterozoic Umberatana

Group.

The Eden Burnside Fault, located to the east of the GE EPA Assessment Area, represents a threshold between

the fractured Precambrian basement rocks of the Mount Lofty Ranges and the Tertiary/Quaternary

sedimentary deposits of the Adelaide Plains.

2.2.2 Hydrogeology

The aquifers identified within the Quaternary age sediments of the Adelaide Plains are typically found within

the coarser interbedded silt, sand and gravel layers of the Hindmarsh Clay formation and vary greatly in

thickness (typically from 1 to 18 m), lithology and hydraulic conductivity. Confining beds between the

Quaternary aquifers consist of clay and silt layers and range in thickness from 1 to 20 m. These confining beds

vary in terms of the amount of coarser grained material they contain, their bulk hydraulic conductivity and/or

the presence and density of fractures. In addition, their absence in some areas allows direct hydraulic

connection between the aquifers.

In total, six Quaternary aquifers have been identified within the Adelaide region and are numbered Q1 to Q6.

The uppermost (Q1) aquifer, assessed as part of the current investigations, is typically located at depths of

between 3 and 10 m below ground level (BGL), with an average thickness of 2 m. Generally, the Q1 aquifer

contains water of low salinity, believed to be due to active recharge from surface drainage and from lateral

inflow from the fractured rock aquifer within the Mount Lofty Ranges to the east. The gradient of the Q1

aquifer is generally flat and flow direction is typically towards the north-west.

A search of the registered bore database maintained by the Department of Environment, Water and Natural

Resources (DEWNR, 2016) identified 46 bores across the general area4. Of these, 10 are located within the GE

EPA Assessment Area, as detailed in Table 2.1. Bore search information is included in Appendix B.

Table 2.1 Information regarding registered groundwater bores located within the GE EPA Assessment Area

Bore ID Location Purpose Status SWL (m BGL)

Salinity (mg/L TDS)

Yield (L/sec)

Aquifer

6628-7869 Glenelg Oval Irrigation Operational 8.7 1,233 29.67 Tertiary (T1)

6628-7886 Cliff Street 7.62 2,085 1.01

6628-7887 Cliff Street 6.71 2,350 0.44

6628-11675 Short Ave Observation 2.38 2,126 0.88

6628-13910 Farr Terrace Drainage Operational 2.10 1.0

i.e. 500 m radius around property at 13 Short Ave (arbitrary location within the GE EPA Assessment Area)

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4



Bore ID Location Purpose Status SWL (m BGL)

Salinity (mg/L TDS)

Yield (L/sec)

Aquifer

6628-17362 Allen Terrace Domestic 2,323 1.0

6628-21507 Wilson Terrace Domestic 6.50 2,448 2.0

6628-21514 Williams Avenue Domestic 4.10 2,081 2.0

6628-21979 Allen Terrace Domestic 5.00 2,352 1.26

6628-27462 Wilson Terrace Backfilled 2,938

Notes:

Shading indicates that information was not recorded in the database.

Abbreviations: SWL = standing water level, TDS = total dissolved solids

2.3 Data quality objectives

The Data Quality Objective (DQO) process, as described in Australian Standard AS4482.1-2005 and the

National Environment Protection (Assessment of Site Contamination) Measure (ASC NEPM, 1999)5

Schedule B2 Guideline on Data Collection, Sample Design and Reporting, and more fully documented in the

NSW DEC (2006) Guidelines for the NSW Site Auditor Scheme, involves a seven-step iterative approach that

was initially developed by the United States Environment Protection Agency (US EPA) to facilitate the

systematic planning and verification of contaminated sites assessment projects.

As stated in ASC NEPM (1999) Schedule B2, the first six steps of the DQO process comprise the development

of qualitative and quantitative statements that define the objectives of the site assessment program and the

quantity and quality of data needed to inform risk-based decisions. These steps enable the project team to

communicate the goals, decisions, constraints (e.g. time, budget) and uncertainties associated with the

project and detail how they are to be addressed. The seventh step comprises the development of a Sampling

and Analysis Quality Plan (SAQP) to generate the data required to adequately characterise site contamination

issues and assess their associated potential environmental and human health risks under the proposed land

use scenario.

The DQOs defined for the GE EPA Assessment Area are summarised in Table 2.2.

All references to the ASC NEPM (1999) refer to the version amended on 16 May 2013.

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5



Table 2.2 Data Quality Objectives

Objective Comment

Step 1 Statement of the Problem The problem is that the site identified as 37-41 Cliff Street Glenelg East hosted a dry cleaning facility for over 50 years and operations on the site during that period involved the storage and use of CHC (predominantly PCE). Previous environmental investigations undertaken on the site, as summarised in Appendix A, have identified soil, groundwater and soil vapour CHC impacts and a groundwater plume of dissolved phase CHC contamination has been found to extend in a hydraulically down-gradient direction (i.e. predominantly north-west). These off-site impacts extend beneath adjoining residential areas of Glenelg East and have the potential to generate soil vapours that could penetrate into houses and present a health risk to local residents. The extent of the groundwater plume, and associated potential soil vapour impacts, was not determined during previous assessment works.

Step 2 The Decision that Needs The assessment works commissioned by the EPA were necessitated to to Result from the Investigation investigate the extent and magnitude of the groundwater CHC contamination

hydraulically down-gradient of the source site and to understand the possible risk to public health from potential soil vapour generation. Fyfe have therefore undertaken soil vapour modelling and vapour intrusion risk assessment works aimed at evaluating whether concentrations of identified groundwater or vapour contaminants pose an unacceptable risk to human health. In addition, groundwater fate and transport modelling has been undertaken to assist the EPA to determine an area where groundwater extraction (i.e. for any purpose other than investigation/monitoring) is precluded to be defined as a Groundwater Prohibition Area (GPA) in accordance with the provisions of Section S103S of the Environment Protection Act 1993.

Step 3 Inputs to the Decision The information that was required to resolve the decision statement includes the collection of physical and chemical data from across the GE EPA Assessment Area. The collected data, as well as physical observations regarding the geology of the area and possible preferential contaminant pathways, was used to determine potential risks to human health via groundwater fate and transport and vapour intrusion modelling.

Step 4 Boundaries of the Investigation

The lateral boundaries of the GE EPA Assessment Area are as defined in Sections 1.3 and 2.1, as depicted on Figure 1. Vertically, the investigations extended as far as the maximum drilled depth (6.5 m BGL).

Step 5 Decision Rules The decision rule will be based upon the identification of predicted indoor air concentrations of CHC compounds, associated with groundwater and soil vapour impacts, which exceed adopted response levels.

Step 6 Decision Error Tolerances The purpose of establishing decision error tolerance is to control the acceptable degree of uncertainty upon which decisions are made, in order to avoid the making of an incorrect decision and to enable identification of additional investigation, monitoring or remediation activities required, on the basis of accurate data, for protection of human health.

The Measuring Quality Objectives (MQO) include the quality assurance (QA) activities that were conducted during the assessment and the quality control (QC) acceptance criteria applicable to the assessment.

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Objective Comment

Step 7 Optimisation of the Sample Collection Design

Data collection was undertaken in general accordance with the methodologies outlined in the ASC NEPM (1999) as well as AS4482.1-2005, AS4482.2-1999, AS/NZS 5667.1:1998, AS/NZS 5667.11:1998, SA EPA (2007) and CRC CARE (2013).

As determined by the EPA, the data collection design included targeted sampling to investigate, and delineate, areas of potential groundwater and soil vapour contamination and to assess potential associated human health risks.

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3. SCOPE OF WORK

The scope of work undertaken by Fyfe was generally consistent with that requested within the original EPA

request for quote (RFQ), dated 7 September 2015. Some modifications to the original workscope occurred

based on site findings and additional site information was collected, where required and as agreed with the

EPA, in order to achieve project objectives.

3.1 Preliminary work

Preliminary work involved the following:

review and summation of all available historical reports (as supplied by the EPA) refer to Appendix A;

development of a preliminary CSM based on a review of the historical data;

preparation of a detailed health and safety plan covering all aspects and stages of the work; and

detailed planning with key stakeholders prior to the execution of the field investigation program.

3.2 Field investigation and laboratory analysis program

The scope of the field investigation program undertaken by Fyfe between 10 November 2015 and 19 January

2016 is summarised in Table 3.1 whereas the scope of the laboratory testing program is summarised in Table

3.2.

Plans showing the various sampling locations are included as Figures 2 and 2A.

Table 3.1 Scope of field investigation program

Scope Item Description of works Date of works

Soil vapour bore drilling and installation

Soil vapour bores (SVP1 to SVP9) were installed to a depth of 1.5 m BGL at nine locations across the GE EPA Assessment Area.

10 and 12 November

Soil vapour sampling

Sampling of soil vapour bores was undertaken using summa canister (TO-15) sample collection methods. Vapour and general gas samples were extracted from a total of 29 locations, including:

nine newly installed bores (SVP1 to SVP9); and

20 existing bores (SGP01 and SGP03 to SGP21)*, seven of which were nested (i.e. installed to depths of either 0.5 and 2.0 m BGL (SGP01) or 1.5 and 2.5 m BGL (SGP05, SGP11, SGP13 and SGP18 to SGP20)) whereas the remainder had been installed to 1.5 m BGL.

17 to 20 November

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Monitoring well drilling and installation

Individual groundwater well permits were obtained from DEWNR prior to well installation copies of the well permits are included in Appendix C.

Groundwater monitoring wells (MW24 to MW31) were installed to depths of between 5.5 and 6.5 m BGL at eight locations across the GE EPA Assessment Area. Wells were developed following installation.

17 to 19 November

Groundwater gauging

All eight newly installed monitoring wells (MW24 to MW31), as well as 24 existing wells (GW01 to GW23 and DC01), were gauged to assess total well depth, standing water level (SWL) and the presence/absence of non aqueous phase liquid (NAPL). This was undertaken as a discrete event prior to the commencement of groundwater sampling.

25 November

Groundwater sampling

Groundwater sampling, undertaken as two distinct events, involved a total of 39 wells, including:

eight newly installed wells (MW24 to MW31)

24 wells (GW01 to GW23 and DC01) installed across the GE EPA Assessment Area during previous investigations; and

seven private bores (PB1 to PB7), located both within, and to the west of, the GE EPA Assessment Area.

Note that one well (MW29) was sampled during both the November 2015 and January 2016 events to confirm results.

25 to 28 November and 18 to 19 January

Outdoor air sampling Passive outdoor (ambient) air sampling was undertaken using Radiello samplers deployed over a seven day period at three locations (AA 1 to AA 3) around the outside of the building at 37-41 Cliff Street (i.e. the source site).

17 to 24 November

Survey of subsurface utility access points

A survey of potential vapour accumulation within 33 subsurface utility access points (SP1 to SP33) at various locations on Cliff Street was undertaken using a hand-held photoionisation detector (PID) unit.

24 November

Crawl space sampling Sampling of the crawl space beneath the residence at 35 Cliff Street was undertaken using TO-15 sample collection methods, with summa canisters deployed over a 24 hour period. The selected sampling locations were beneath the spare room, kitchen and bedroom of the residence samples were labelled accordingly (i.e. with the prefix CS).

Anemometers were also deployed at three locations within the crawl space at 35 Cliff Street as well as within the garage. Anemometer data are included in Appendix D and their applicability was considered with respect to the VIRA.

25 to 26 November

Indoor air sampling Sampling of indoor air within the residence at 35 Cliff Street was undertaken using TO-15 sample collection methods, with summa canisters deployed over a 24 hour period. The selected sampling locations were within the spare room, kitchen and bedroom of the residence samples were labelled accordingly (i.e. with the prefix AA).

25 to 26 November

Sampling of indoor air within the residence at 35 Cliff Street was also undertaken using Radiello samplers, deployed over an eight day period. The selected sampling locations were within the spare room, kitchen, bedroom and garage of the residence samples were labelled accordingly (i.e. with the prefix AA, apart from the garage).

26 November to 4 December

Surveying The locations of the newly installed soil vapour bores and groundwater wells were surveyed by a licensed Fyfe surveyor relative to Geocentric Datum of Australia (GDA) 1994 and the top of each bore was surveyed relative to Australian Height Datum (AHD). The survey data are included in Appendix E.

8 December

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Aquifer testing Aquifer permeability testing was undertaken on all eight newly installed wells (MW24 to MW31) and two existing wells (GW3 and GW13). Data was subsequently evaluated by Arcadis Pty Ltd (Arcadis) to estimate the hydraulic conductivity of the aquifer beneath the GE EPA Assessment Area (refer to Section 6.8.3).

27 November and 10 December 2015

Residential survey A door-knock/survey of residences within a portion#

of the GE EPA Assessment Area was undertaken by EPA and Fyfe representatives refer to Section 7 for further details (although the full results have been reported separately to the EPA for privacy purposes).

27 November

Notes:

*Soil vapour bore SGP02 was blocked and could not be sampled. #as determined by the EPA

Table 3.2 Scope of laboratory testing program

Scope Item Description of works

Soil Three core samples collected during the drilling of groundwater wells MW24, MW25 and MW30 testing were analysed for:

dry density;

specific gravity/soil particle density;

moisture content; and

particle size distribution (PSD).

Moisture content was also analysed in 20 soil samples collected from various depths during the drilling of the groundwater monitoring wells.

Groundwater testing Groundwater samples from 39 existing and newly installed monitoring wells, as well as a repeat sample collected from MW29, were analysed for CHC.

Groundwater samples from selected wells (GW02, GW12, GW20, GW22, MW25, MW26, MW29 and MW31) were also analysed for the following:

major cations and anions (calcium, magnesium, sodium, potassium, chloride and alkalinity);

natural attenuation parameters (carbon dioxide, sulfate, ferrous iron, manganese, nitrate); and

additional components (aluminium, iron, nitrite).

Soil vapour testing All soil vapour samples were analysed for CHC and general gases.

Crawl space, indoor and outdoor air testing

Crawl space, indoor air and outdoor air samples collected using summa canisters and/or Radiello samplers were analysed for CHC.

Notes:

CHC included trichloroethene (TCE), tetrachloroethene (PCE), cis-1,2-dichloroethene (cis-1,2-DCE), trans-1,2dichloroethene (trans-1,2-DCE), vinyl chloride (VC), 1,1-dichloroethane (1,1-DCA) and 1,1-dichloroethene (1,1-DCE).

General gases included helium, hydrogen, oxygen, nitrogen, methane, carbon dioxide, ethane, argon, carbon monoxide and ethylene.

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3.3 Data interpretation

Following the receipt and collation of the field and laboratory data, hydrogeological (fate and transport) and

vapour intrusion risk assessment (VIRA) modelling (refer to Sections 8 and 9, respectively) was undertaken to

enable an assessment of risk and to refine the CSM (Section 10).

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4. METHODOLOGY

Field methodologies employed by Fyfe during the installation/construction of the soil vapour bores and

groundwater wells, as well as during the sampling of various media, are detailed in Table 4.1. Relevant field

sampling sheets are included in Appendices F (soil vapour) and G (groundwater) and borehole/groundwater

well log reports are presented in Appendices H and I.

Prior to the commencement of the field investigations, a site specific Health and Safety Plan (HSP), including

Safe Work Method Statements (SWMS) and a Job Hazard Analysis (JHA), was prepared all personnel

working at the site were required to read, understand, sign and conform to the HSP.

Also prior to the commencement of intrusive investigation works, both Fyfe and EPA personnel walked over

the GE EPA Assessment Area to consider and discuss the practicability and accessibility of each proposed

sampling location. Once agreed, each proposed drilling location was cleared of underground services by a

professional service location company (BRP) using conventional (electronic) service detection methods as

well as Ground Penetrating Radar (GPR). Where underground or overhead services were present and/or

deemed to be a potential safety risk during drilling activities, the drill location was moved to an area

considered by the Fyfe representative and service locator to be safe. All changes to drilling locations were

recorded on a site plan for future reference. Any subsequent work undertaken by Fyfe (i.e. additional to the

requirements of the EPA RFQ) was subjected to similar controls (where relevant).

Given that works were undertaken within suburban streets, Fyfe employed the services of a qualified traffic

management company (Workzone) in order to ensure safety for pedestrians and road users, minimal

disruption to traffic flow and the provision of a safe working environment.

Table 4.1 Summary of field methodologies

Activity Details

Soil vapour bore Soil vapour bores were drilled by Aussie Probe using a combination of hand augering and installation mechanical pushtube techniques.

Within each soil vapour bore, teflon tubing attached to a soil vapour probe was inserted to the base of the hole, which had been prefilled with approximately 0.05 to 0.1 m of clean filter pack sand. An additional 0.4 to 0.45 m of sand (i.e. approximately 0.5 m in total) was then added to the hole and topped by a bentonite plug seal of approximately 0.3 to 0.5 m thickness. The installation was completed with grout to surface, topped with a standard flush-mounted gatic cover.

Groundwater well Groundwater wells were drilled by A&S Drilling using a combination of hand augering, installation mechanical pushtube and auger (hollow or solid) techniques.

Following the completion of drilling, each borehole was fitted with 50 mm class 18 uPVC casing with a basal 3 m long section of slotted well screen. A filter pack, comprising clean graded sands of suitable size to provide sufficient inflow of groundwater, was installed within the annular space between the borehole and the well casing and extended from the base of the screened interval to approximately 0.5 m above the termination of the slotted casing.

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Activity Details

A minimum 0.5 m long bentonite collar, comprising pelleted or granulated bentonite, was placed above the filter pack to prevent water seepage downward along the well casing or borehole from ground surface. Each well was grouted up to surface level and fitted with a ground flush-mounted (lockable) steel gatic cover. Care was taken to ensure that the gatic was flush mounted to prevent tripping and/or lawn mowing hazards.

Soil logging and sampling Drill cores from hand augers, push tubes and/or augers were discharged into clean core trays and gloved hands were used to recover samples (into laboratory supplied sample jars) for moisture content analysis. Disposable nitrile gloves worn by field personnel were changed prior to the collection of each sample. Samples were chilled during transport to the analytical laboratory.

Soil logging was undertaken in accordance with the ASC NEPM (1999), which endorses AS1726-1993 Geotechnical Site Investigations. In addition to the requirements of AS17261993, particular attention was paid during logging to any lithological variations such as sand/gravel lenses or secondary porosity (such as clay fracturing) which may act as potential preferential pathways for contaminant vapour/groundwater migration through the sub-surface. Any identified olfactory or visual evidence of contamination was clearly identified on the borehole log sheet, along with the presence of any fill material and/or any other evidence of contamination.

Cores for geotechnical analysis were collected using push tube sampling methodologies to obtain undisturbed samples. Within each core tray forwarded to the geotechnical laboratory, those section(s) of core to be tested were wrapped in plastic cling wrap as soon as possible after removal from the core barrel in order to retain moisture content.

Core photography Following completion of drilling at each location, each core box was photographed under natural light conditions, prior to the collection of samples. Care was taken to ensure that the natural soil conditions (including in situ colour, weathering condition, void filling etc.) were clearly evident and that any structural features were clearly exposed. Drill core photographs are included in Appendix J.

Field screening of soils Field screening of individual soil layers was undertaken at all drilling locations and involved the use of a PID unit fitted with an 11.7 eV lamp (i.e. as considered suitable for the detection of CHC). The PID unit was calibrated by the hire company prior to delivery and was checked on a daily basis against an isobutylene calibration gas of known concentration.

Field screen samples were collected with care to ensure the sample was representative of the soil stratum from which it was collected and experienced minimal loss of volatile compounds. The soil material was placed immediately into a zip lock bag and sealed, ensuring the bag was half filled (i.e. such that the volume ratio of soil to air was equal). Soil clumps within the bag were manually broken up and the bag was left to rest for a minimum of five minutes but no longer than 20 minutes. Prior to testing, the bag was shaken vigorously to release any vapours within the soil. To test, the tip of the PID probe was inserted into the bag and the maximum volatile organic compound (VOC) reading recorded after a nominal 10 second period or when the reading had peaked. Results were recorded on the appropriate bore log sheets.

Groundwater well development

Following installation, the wells were developed by purging approximately four to five well volumes (generally about 20 litres) from the casing with a steel bailer to ensure hydraulic connectivity with the aquifer formation.

Groundwater gauging Groundwater levels in the newly installed and existing monitoring wells located across the GE EPA Assessment Area were gauged using an interface probe prior to the commencement of the groundwater sampling program. All monitoring wells were gauged for SWL, the potential presence of NAPL and the total well depth.

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Activity Details

Groundwater sampling The majority of the wells were sampled using low flow (micropurge) techniques. Where the highly turbid groundwater encountered in some wells resulted in continual blockage of the pump, HydraSleeve

TM (grab sampling) methodology was used instead. A single well

(MW29), originally sampled using a HydraSleeveTM

(i.e. due to high turbidity) was later re-sampled using a disposable bailer. Private bores were sampled using a combination of the above methods as well as point of discharge sampling (i.e. from a tap or sprinkler where no other method was possible).

Groundwater samples were collected in laboratory-supplied screw top bottles, containing appropriate preservative (if required) with no headspace allowed. Samples were chilled during storage and transport to the analytical laboratory.

Disposable nitrile gloves worn by field personnel were changed prior to the collection of each sample.

Samples for metals analysis were not filtered in the field due to high sediment load. These samples were collected in sample jars that had been washed clean of preservative (acid) using potable (tap) water. A sample of potable water was also analysed for metals (manganese, ferrous iron) to assess the potential for any significant cross-contamination.

Low Flow Methodology:

The low flow sampling technique involved the following:

the flow rate (0.2 to 1 L/min) was regulated to maintain an acceptable level of drawdown, with minimal fluctuation of the dynamic water level during pumping and sampling

groundwater drawdown was monitored constantly during purging and sampling using an interface probe

water quality parameters were considered to have stabilised when the following ranges were recorded over three consecutive readings:

electrical conductivity: 5%

pH: 0.1

temperature: 0.2 C

dissolved oxygen: 10%

redox potential: 10 mV the stabilisation parameters were recorded on field logging sheets after every one litre

of groundwater purged, using a calibrated meter water quality meter and a flow cell suspended in a bucket with litre intervals marked; and

samples were collected once three consecutive stabilisation parameters were recorded and a volume of between three and seven litres was purged prior to sampling.

HydrasleeveTM

Methodology:

The HydraSleeveTM

(grab) sampling technique involved attaching a stainless steel weight to the bottom, and a wire tether clip to the throat, of the HydraSleeve

TM before lowering it

into the water column to the desired depth and allowing it to fill with groundwater. After a period of approximately 30 minutes, the HydraSleeve

TM was quickly and smoothly

withdrawn from the well and the contents were transferred into the sample containers. Water quality parameters were not measured during sampling due to insufficient water volume remaining in the Hydrasleeve

TM after the samples were decanted.

Bailing Method

Bailing methodology was only used for a single well (MW29) in January 2016 due the low volume of water encountered during attempted re-sampling (i.e. which rendered the Hydrasleeve methodology impractical). This involved the use of a disposable bailer,

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Activity Details

whereby care was taken during purging and sampling to ensure minimal agitation of the water column whilst lowering and raising the bailer. During purging, water quality parameters were recorded at set intervals which were dependant on the volume of water required for removal and/or the recharge rate.

Once water quality parameters had stabilised over three consecutive readings (as per low flow methodology), the bailer was reinserted to sample the well and the sample was decanted into the sample jars by inserting a device into the bottom of the bailer, ensuring minimising exposure to the atmosphere.

Hydraulic testing Rising head permeability (slug) tests were undertaken to estimate the hydraulic conductivity (K) of the aquifer within various parts of the GE EPA Assessment Area. The tests involved removing a slug of water from each well using a disposable bailer, following which recovery of the groundwater level was recorded using an electronic data-logging pressure transducer set to record water levels at approximate pre-planned intervals (as required for computer analysis).

Soil vapour sampling All soil vapour sampling works were undertaken by SGS Leeder using suitably trained and experienced personnel SGS holds National Association of Testing Authorities (NATA) accreditation for all soil vapour sampling and laboratory analytical works.

Soil vapour samples were collected using summa canisters and analysed using the US EPA TO-15 method. Sampling involved the connection of a passivated 1 L stainless steel canister to the teflon tubing extending from the soil vapour probe and the use of a soil gas sampling train to restrict flow to a maximum rate of 200 mL/min. Canister vacuum pressure was monitored during sampling to enable calculation of the volume of sample drawn into the canister the small amount of vacuum left in the canister at the end of the sampling procedure was measured in the laboratory to check if any leaks occurred during transit. A shroud was set up around the sampling point and tracer chemicals were introduced at high concentrations by flooding the shroud with helium and placing a cloth soaked in isopropyl alcohol (IPA) into the shroud.

Each canister was cleaned and certified by SGS Leeder prior to use (refer to Appendix M) and back-up coconut shell carbon sorbent tube samples were also collected.

Summa canisters did not require chilling during transport to the analytical laboratory.

Crawl space, indoor air Radiello samplers: and outdoor air sampling Radiello samplers were placed in nominated locations inside the residence at 35 Cliff

Street as well as within selected outdoor locations at 37-41 Cliff Street (source site).

Nitrile gloves were worn during deployment and collection of the samplers and particular care was taken to ensure that the adsorbing cartridge was not touched. Care was also taken to ensure that each label was completed correctly (with start and end time and dates) and that the label accompanied the adsorbing cartridge at all times.

Deployment heights varied depending on the location but were generally aimed to coincide with headspace at indoor and outdoor air sampling locations. After a period of between seven and eight days (refer to Table 3.1), the samplers were removed from their locations and submitted for laboratory TO-17 analysis.

Radiello samplers did not require chilling during transport to the analytical laboratory.

Summa canisters:

Summa canisters were placed in nominated locations inside, and within the crawl spaces of, the residence at 35 Cliff Street (refer to Table 3.1). The canisters were left in place for a period of 24 hours, following which they were retrieved and forwarded to the laboratory for TO-15 analysis.

Summa canisters did not require chilling during transport to the analytical laboratory.

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Activity Details

Waste water disposal Waste water was stored within 205 litre drums on the property at 35 Cliff Street prior to removal/disposal by a licensed waste removal company.

Waste soil disposal All surplus soil cores and cuttings were stored within 205 litre drums on the property at 35 Cliff Street prior to disposal. Analytical results pertaining to the soils were forwarded to the licensed receiving facility and all of the soil has been classified as Waste Fill, in accordance with the Environment Protection Regulations 2009.

Survey of subsurface utility access points

Subsurface utility access points along Cliff Street were assessed for the presence of VOCs via the use of a PID unit fitted with an 11.7 eV lamp (i.e. as considered suitable for the detection of chlorinated compounds). The unit was calibrated against an isobutylene calibration gas of known concentration prior to use.

4.1 Laboratory analysis

The following laboratories were used for the analysis of the environmental samples:

complete soil cores for geotechnical sample analysis were forwarded to SMS Geotechnical;

primary groundwater and soil (for moisture content analysis) samples collected by Fyfe were analysed at

the SGS Leeder laboratory;

primary soil vapour and air (crawl space, indoor and outdoor) samples collected by SGS Leeder, were

analysed at their laboratory; and

secondary groundwater, soil vapour and air samples collected by Fyfe and SGS Leeder were forwarded

to Australian Laboratory Services (ALS).

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5. QUALITY ASSURANCE AND QUALITY CONTROL

Data quality is typically discussed in terms of accuracy, precision and representativeness. In order to assess

the quality of the data collected during the Fyfe investigation program, specific QA/QC procedures were

implemented during both the field sampling and laboratory analysis programs, as detailed in the following

sections.

5.1 Field QA/QC

Field QA procedures undertaken during the recent investigations included the collection of the following QC

samples, aimed at assessing possible errors associated with cross contamination as well as inconsistencies in

sampling and/or laboratory analytical techniques:

intra-laboratory duplicate (duplicate) samples: submitted to the same (primary laboratory) to assess

variation in analyte concentrations between samples collected from the same sampling point and/or the

repeatability (precision) of the analytical procedures;

inter-laboratory duplicate (split or triplicate) samples: submitted to a second laboratory to check on the

analytical proficiency (accuracy) of the results produced by the primary laboratory;

equipment rinsate blank samples: collected during groundwater sampling only and used to assess cross-

contamination that may have occurred from sampling equipment during sampling; and

trip blank samples: used to assess whether cross-contamination may have occurred between samples

during transport.

Whereas analyte concentrations within the trip blank samples should be below the laboratory practical

quantification limit (PQL), the inter- and intra-laboratory duplicate sample results are assessed via the

calculation of a relative percentage difference (RPD), as follows:

2/)21(

100)21(

ionConcentrationConcentrat

xionConcentrationConcentratRPD

A maximum RPD within the range of 30% to 50% is generally considered acceptable, with higher RPD values

often recorded for organic compounds and where low concentrations of an analyte are recorded.

Unless stated otherwise, QC sample results are included in the summary data tables in Appendix K.

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5.1.1 Soil

Table 5.1 presents conformance to field QA/QC procedures undertaken as part of the (limited) soil

investigations.

Table 5.1 Field QA/QC procedures - Soil

QA/QC Item Detail

Field procedures Field procedures were undertaken in accordance with ASC NEPM (1999), Australian Standards AS4482.1-2005 and AS4482.2-1999 and Fyfe standard field operating procedures. Details are provided in Table 4.1.

Calibration of field equipment

Documentation regarding the calibration of field equipment is included in Appendix L.

Decontamination of equipment

All equipment that was in contact with soil cores prior to sampling (core trays and drill core barrels) were decontaminated between sampling locations using potable water and Decon 90 phosphate free detergent.

Sample tracking Chain of Custody (COC) documentation was used for the transport of all samples to the laboratory and is included in Appendix M.

Sample preservation and storage

Samples for moisture content and potential COPC analysis were kept in laboratory supplied containers in a portable chilled insulated box (esky) prior to, and during, transport to the laboratory.

Soil cores for geotechnical analysis were provided whole (i.e. in core trays) to the analytical laboratory, with those sections to be analysed wrapped in plastic cling wrap.

Duplicate samples It was considered that the analysis of soil moisture content did not warrant duplicate sample analysis.

Rinsate blank samples Two equipment rinsate blank samples were collected from decontaminated core barrels on each of two days of drilling and analysed for CHC to confirm the effectiveness of the decontamination procedures.

The analytical results obtained for the rinsate blank samples were all below the laboratory PQL, thereby indicating that decontamination practices during the soil drilling program were acceptable.

Trip blank samples A trip blank sample was included within each of two containers (eskies) of sample jars provided by the analytical laboratory and returned to the analytical laboratory. Trip blank samples were analysed for CHC.

The analytical results obtained for the trip blank samples were all below the laboratory PQL, thereby indicating that there was no impact on sample quality during storage or transport to the analytical laboratory.

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5.1.2 Groundwater

Table 5.2 presents conformance to field QA/QC procedures undertaken as part of the groundwater

investigations.

Table 5.2 Field QA/QC procedures - Groundwater

QA/QC Item Detail

Field procedures Field procedures were undertaken in accordance with ASC NEPM (1999), Australian/New Zealand standards AS/NZS 5667.1:1998 and AS/NZS 5667.11:1998, SA EPA (2007) and Fyfe standard field operating procedures. Details are provided in Table 4.1.

Calibration of field equipment

Documentation regarding the calibration of field equipment is included in Appendix L.

Decontamination of

equipment

All disposable equipment (tubing, pump bladders, plastic bailers, bailer cord and Hydrasleeve

TM units) were replaced between wells. Re-usable equipment (micropurge

pump) was decontaminated between sampling locations using potable water and Decon 90 phosphate free detergent.

Sample tracking COC documentation was used for the transport of all samples to the laboratory and is included in Appendix M.


Samples were kept in laboratory supplied containers in a portable chilled insulated box (esky) prior to, and during, transport to the laboratory.

Duplicate samples Nine intra-laboratory and one inter-laboratory duplicate samples were analysed, with respect to 40 primary groundwater samples*, for CHC thereby constituting a ratio of approximately one duplicate per four primary samples (or 25%).

One intra-laboratory duplicate sample was analysed, with respect to eight primary groundwater samples, for the remaining parameters thereby constituting a ratio of approximately 12.5%.

Intra- and inter-laboratory duplicate sample RPDs were calculated where both data sets had a reported concentration above the specific analyte laboratory PQL. All calculated RPDs for CHC were within the acceptable range whereas higher RPDs were obtained for aluminium (149%) and iron (131%) in the intra-laboratory duplicate sample pair.

Rinsate blank samples Five equipment rinsate blank samples collected from the internal surface of a bladder (prior to use) and/or the pump housing over the two groundwater sampling periods were analysed for CHC to confirm the effectiveness of the decontamination procedures.

The analytical results obtained for the rinsate blank samples were all below the laboratory PQL, thereby indicating that decontamination practices during the groundwater sampling program were acceptable.

Trip blank samples A trip blank sample was included within four containers (eskies) of sample bottles provided by the analytical laboratory and returned to the analytical laboratory. Trip blank samples were analysed for CHC.

The analytical results obtained for the trip blank samples were all below the laboratory PQL, thereby indicating that there was no impact on sample quality during storage or transport of the samples to the analytical laboratory.

Notes:

No duplicate samples were collected during the deployment of HydrasleeveTM

and bailing methodologies.

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5.1.3 Soil vapour

Tables 5.3 presents conformance to field QA/QC procedures undertaken as part of the soil vapour

investigations.

Table 5.3 Field QA/QC procedures Soil vapour

QA/QC Item Detail

Field procedures Field procedures were undertaken in accordance with ASC NEPM (1999) as well as ASTM (2001, 2006), IRTC (2007) and CRC CARE (2013) guidance. Details are included in Table 4.1.



Summa canisters were stored in specially constructed cases during transport to the analytical laboratory at ambient temperature.

Duplicate samples Three intra-laboratory and four inter-laboratory duplicate samples were analysed for CHC and general gases, with respect to 36 primary soil vapour samples, thereby constituting a ratio of approximately one duplicate per five primary samples (or 19%).

Intra- and inter-laboratory duplicate RPDs were calculated where both samples had a reported concentration above the laboratory PQL. Although the majority of the RPD results were considered acceptable (i.e. 50% for field duplicates, as advised by SGS Leeder, based on California EPA (2012)), inter-laboratory duplicate sample pair SVP5/SVP5 had a high RPD (86%) for helium. SGS Leeder personnel have advised that such RPD exceedances are not unusual and no concerns have been raised regarding the overall quality of the data.

Leak testing The elevated IPA concentration (1,700,000 g/m3) and the presence of 20% helium in

soil vapour sample SGP11 2.5 is considered indicative of a significant leak and the sample data have not been used in the VIRA modelling.

A small leak, or ambient drawdown, may also have occurred with respect to SGP01 (short) which contained 4.7% helium according to ITRC (2007) and NJDEP (2013), the presence of 5% helium in samples is indicative of a significant leak or ambient drawdown. It was noted by SGS Leeder that this bore had been poorly installed, (i.e. contains a bentonite seal but no grout or concrete seal inside the gatic cover). Given that the leak was relatively small, the data from this bore were still considered to be valid.

Shroud samples The analytical results obtained for the helium shroud (Tedlar bags), helium blank and IPA shroud (carbon tube) samples were all considered to be satisfactory.

Note:

The American Society for Testing and Materials (ASTM) is an internationally recognised source of testing methods.

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5.1.4 Indoor, outdoor and crawl space air

Table 5.4 presents conformance to field QA/QC procedures undertaken as part of the crawl space, indoor air

and outdoor air sampling programs.

Table 5.4 Field QA/QC procedures Crawl space, indoor and outdoor air sampling

QA/QC Item Detail

Field procedures Field procedures were undertaken in accordance with ASC NEPM (1999) as well as ASTM (2001, 2006), IRTC (2007), CRC CARE (2013) guidance and the Radiello sampler manual produced by the supplier. Details are included in Table 4.1.



Radiello samplers were kept in glass vials (when not deployed) and were transported to the laboratory in a portable insulated box (esky), but at ambient temperature.

Summa canisters were stored and transported in specially constructed cases during transport, also at ambient temperature.

Duplicate samples Two intra-laboratory Radiello duplicate (indoor and outdoor air), two intra-laboratory summa canister (indoor air and crawl space) and one inter-laboratory summa canister (indoor air) duplicate samples were collected.

The RPD results were considered acceptable (i.e. less than 50%, as advised by SGS Leeder, based on California EPA (2012)).

Trip blank samples Trip blank samples, included within containers of Radiello samplers provided by the manufacturer and forwarded to the analytical laboratory, were analysed for CHC. The analytical results obtained for the two trip blank samples were all below the laboratory PQL, thereby indicating that there was no impact on sample quality during storage or transport to the analytical laboratory.

5.2 Laboratory QA/QC

Laboratory QA procedures generally include the performance of a number of internal checks of data precision

and accuracy that are aimed at assessing possible errors associated with sample preparation and analytical

techniques. Specific types of QC samples analysed by laboratories, and the relevant acceptance criteria are as

follows:

internal laboratory replicate samples: maximum RPD values of 20% to 50%;

spike recoveries: results between 70% and 130%, although this varies depending on laboratory PQL; and

laboratory control blanks: results below the laboratory PQL.

Table 5.5 presents conformance to laboratory QA/QC procedures undertaken as part of the overall

investigation program.

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Table 5.5 Laboratory QA/QC procedures

QA/QC Item Detail

Samples analysed and extracted within relevant holding times

All samples were analysed within specified holding times.

Laboratories used and NATA accreditation

The laboratories used (SGS Leeder, ALS and SMS Geotechnical) were NATA accredited for the analyses undertaken.

Appropriate analytical methodologies used*

Refer to the laboratory reports in Appendix M.

Laboratory PQL The laboratory PQL is the minimum concentration of an analyte (substance) that can be measured with a high degree of confidence that the analyte is present at, or above, that concentration. The PQL are presented in the laboratory certificates of analysis (Appendix M) and are considered to be generally appropriate notable exceptions include the following:

CHC in soil vapour samples collected from existing bores SGP01 (short and long), SGP03, SGP05 (short and long), SGP07, SGP11 (2.5) and SGP19 (short and long); and

CHC in the inter-laboratory duplicate soil vapour samples analysed by ALS.

As elevated laboratory PQL did not apply to the main contaminants of concern (i.e. PCE and TCE), this is not considered to be of concern with respect to the assessment of soil vapour, and its associated potential human health risks, across the GE EPA Assessment Area.

Laboratory internal QC analyses

Results obtained for the laboratory internal QC samples were within the acceptable limits of repeatability, chemical extraction and detection. Within SGS Leeder report M152657, it was stated that some analyte concentrations (i.e. sodium, magnesium, calcium) could not be determined in the spike samples due to high levels of compounds interfering with analysis.

Full details regarding laboratory QA/QC procedures and results are presented in the certified laboratory certificates contained in Appendix M.

Note:

*i.e. in accordance with Schedule B3 of ASC NEPM (1999)

5.3 QA/QC summary

In summary, it is considered that:

the field QA/QC programs were generally undertaken with regard to relevant legislation, standards

and/or guidelines and were sufficient for obtaining samples that are representative of site conditions;

and

the overall laboratory QA/QC procedures and results were adequate, such that the laboratory analytical

results obtained are of acceptable quality for addressing the key objectives outlined in Section 1.5.

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6. RESULTS

6.1 Surface and sub surface soil conditions

Soil vapour borehole and groundwater well log reports are included in Appendices H and I, respectively, and

provide details of the soil profile encountered at each sampling location. Photographs of drill cores obtained

as a part of the intrusive investigation works are included as Appendix J.

Where encountered, fill materials extended to depths of between 0.05 and 0.45 m BGL and included a range

of different soil types (gravels, sands and clays), with only minimal waste inclusions (i.e. plastic or bitumen

fragments) identified at some locations.

Underlying natural soils (encountered to the maximum drill depth of 6.5 m BGL) generally comprised

interspersed layers of the following:

low to medium plasticity brown to grey silty or sandy clay with calcareous gravel/inclusions;

low to high plasticity brown, orange-brown or red-brown silty clay often containing gravel (ironstone,

siltstone) and/or calcareous inclusions;

medium to high plasticity brown to dark brown clay with trace sand and/or calcareous gravel; and

fine to medium-grained red-b

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