National Environment Protection (Assessment of Site Contamination) Amendment Measure 2013 (No. 1) (Cth)
National Environment Protection (Assessment of Site Contamination) Amendment Measure 2013 (No. 1)
The NATIONAL ENVIRONMENT PROTECTION COUNCIL makes the following National Environment Protection Measure under subsection 20(1) of the National Environment Protection Council Act 1994 of the Commonwealth, the National Environment Protection Council (New South Wales) Act 1995 of New South Wales, the National Environment Protection Council (Victoria) Act 1995 of Victoria, the National Environment Protection Council (Queensland) Act 1994 of Queensland, the National Environment Protection Council (Western Australia) Act 1996 of Western Australia, the National Environment Protection Council (South Australia) Act 1995 of South Australia, the National Environment Protection Council (Tasmania) Act 1995 of Tasmania, the National Environment Protection Council (Northern Territory) Act 1994 of the Northern Territory, and the National Environment Protection Council Act 1994 of the Australian Capital Territory.
Dated: 11 April 2013
Mr Theo Hooy
National Environment Protection Council Executive Officer on behalf of the
National Environment Protection Council
Contents
1 Name of measure 1
2 Commencement 1
3 Authority 1
4 Schedule(s) 1
Schedule 1—Amendments 2
National Environment Protection (Assessment of Site Contamination) Measure 1999 2
1 Name of measure
This measure may be cited as the National Environment Protection (Assessment of Site Contamination) Amendment Measure 2013 (No. 1).
2 Commencement
This measure commences on the day after it is registered.
3 Authority
This measure is made under the National Environment Protection Council Act 1994 and the equivalent provision of the corresponding Act of each participating State and Territory.
4 Schedule(s)
Each instrument that is specified in a Schedule to this instrument is amended or repealed as set out in the applicable items in the Schedule concerned, and any other item in a Schedule to this instrument has effect according to its terms.
Schedule 1—Amendments
National Environment Protection (Assessment of Site Contamination) Measure 1999
1 Introductory note
Omit “NEPC”, substitute “National Environment Protection Council”.
2 Section 3 (definition of Contamination)
After “added”, insert “as a direct or indirect result of human activity”.
3 Section 3 (definition of Health Risk Management)
Omit “alternative actions and selecting options in response to”, substitute “and implementing appropriate options to address risks identified from”.
4 Section 3 (definitions of Investigation level and Response Level)
Repeal the definitions.
5 Section 3
Insert:
Investigation or Screening Level means the concentration of a contaminant above which further appropriate investigation and evaluation will be required.
6 Section 3 (definition of Risk)
Omit “hazardous agent” (wherever occurring), substitute “chemical substance”.
7 Section 6 (principle 3)
Omit “Levels or Response”, substitute “or Screening”.
8 Section 6 (principle 5)
Repeal the principle, substitute:
(5) Planning and development
Authorities of participating jurisdictions (at local and State government level) that consent to developments, or changes in land use, should ensure a site that is being considered for development or a change in land use, and that the authorities ought reasonably know if it has a history of use that is indicative of potential contamination, is suitable for its intended use.
(5A) Decommissioning of industrial activities
Industries, including mining and mineral processing industries, are responsible for ensuring that, when equipment on a site is dismantled or a site is otherwise decommissioned, appropriate measures are taken to leave the site in a safe and stable condition in order to prevent or, as far as practical, minimise adverse long‑term environmental (physical, social and economic) impacts.
9 Section 6 (principle 7)
Repeal the principle, substitute:
(7) Community engagement
If a community could reasonably have an interest in the potential site contamination, community engagement should start at an early stage of, and continue throughout, the process of assessment of site contamination.
10 Section 6 (principle 10)
Repeal the principle, substitute:
(10) Site assessment process
The recommended general process for the assessment of site contamination is shown in Schedule A. The assessment should be conducted by professionals who have the relevant qualifications, competencies and experience.
11 Section 6 (principle 11)
Omit “a contaminant”, substitute “contamination”.
12 Section 6 (principle 12)
Repeal the principle, substitute:
(11A) Work health and safety
There should be appropriate work health and safety measures (including training) in place for any personnel involved in the assessment of site contamination, in accordance with the applicable work health and safety legislation.
(12) Environmental impact
The assessment of site contamination should include a consideration of risks to water resources and other ecological risks.
During the assessment, the on‑site and off‑site impacts of contaminants should be appropriately managed to prevent adverse impacts, particularly impacts relating to air emissions, surface water and groundwater.
13 Section 6 (principle 13)
Omit “implement data quality objectives, and”, substitute “develop data quality objectives and implement”.
14 Section 6 (principle 13)
Omit “equivalent organisation”, substitute “organisation recognised under NATA’s Mutual Recognition Agreement (MRA) Network”.
15 Section 6 (principle 14)
Repeal the principle, substitute:
(14) Risk assessment
The initial assessment of human health risks and ecological risks may be undertaken by comparing levels of contaminants on the site with appropriate investigation or screening levels or, if necessary, by undertaking a site‑specific risk assessment. The initial assessment may be followed by a more detailed assessment of human health risks and ecological risks.
An assessment of human health risks and ecological risks should, if practicable, take into account any additive, synergistic and antagonistic effects of mixing chemical substances.
16 Section 6 (principle 15)
Omit “the need to adequately protect”, substitute “adequately protecting”.
17 Section 6 (principle 15)
After “wherever they live;”, insert:
• that the environmental values of water are maintained for future generations;
18 Section 6 (principle 16)
Omit “if practicable,”.
19 Section 6 (principle 16)
After “appropriate management strategy.”, insert:
When deciding which option to choose, the sustainability (environmental, economic and social) of each option should be considered, in terms of achieving an appropriate balance between the benefits and effects of undertaking the option.
20 Section 6 (principle 17)
Omit the first sentence, substitute:
In the assessment of site contamination the following sources are recognised as requiring specialised forms of assessment and initially, information should be sought from the relevant environmental protection agency for advice on assessing sites with:
(a) unexploded ordnance;
(b) radioactive substances;
(c) pathogenic materials and waste;
(d) contaminated sediments;
(e) explosive gas mixtures.
21 Section 6 (principle 18)
Omit “Aboriginal and Torres Strait Islander Commission, the Australian Heritage Commission”, substitute “National Congress of Australia’s First Peoples, the Australian Heritage Council”.
22 Subsection 7(1)
Omit “recommended”, substitute “general”.
23 Subsection 7(2)
Omit “that form part of this Measure”.
24 Section 8
Omit “which indicates”, substitute “indicating”.
25 Section 8
Omit the second sentence, substitute:
The preliminary investigation usually involves:
(a) establishing a site history to identify the characteristics of the site (such as the location and layout of the site, the building construction on the site, the geological setting, current and past activities at the site, current and past uses of the site, and heritage considerations); and
(b) inspecting the site; and
(c) interviewing representatives for the site.
26 Section 8
Omit “definition.”, substitute “evaluation.”.
27 Section 8
Omit “and staining”, substitute “or staining”.
28 Section 8
Omit “investigation levels in Schedule B(1)”, substitute “applicable investigation or screening levels”.
29 Section 8
Omit “incorporate the”, substitute “involve both”.
30 Subsection 9(2)
Omit “next following”, substitute “immediately after”.
31 Section 10
Omit “five years from the date of commencement”, substitute “every 10 years after the measure was last amended”.
32 Schedule A
Repeal the Schedule, substitute:
Schedule A—Recommended general process for assessment of site contamination
33 Schedule B
Repeal the Schedule, substitute:
Schedule B—General guidelines for the assessment of site contamination
The following general guidelines provide guidance on the possible ways of achieving the desired environmental outcome (PART 3 of the Measure) for the assessment of site contamination and should only be considered in relation to the assessment of site contamination.
Index of guidelines Schedule B1—Guideline on Investigation Levels for Soil and Groundwater Schedule B2—Guideline on Site Characterisation
Appendix A Possible analytes for soil contamination
Appendix B Data quality objective (DQO) process
Appendix C Assessment of data quality
Appendix D Example data presentation on scale drawings and borehole logs
Appendix E Dioxins and dioxin‑like compounds
Schedule B3—Guideline on Laboratory Analysis of Potentially Contaminated Soils
Appendix A Determination of total recoverable hydrocarbons (TRH) in soil
Schedule B4—Guideline on Site‑Specific Health Risk Assessment Methodology
Appendix A Structure of a risk assessment report
Schedule B5a—Guideline on Ecological Risk Assessment
Appendix A Summary of the EILs for fresh and aged contaminants in soil with various land uses
Appendix B Mixtures of chemicals
Schedule B5b—Guideline on Methodology to Derive Ecological Investigation Levels in Contaminated Soils
Appendix A Review and comparison of frameworks for deriving soil quality guidelines in other countries
Appendix B Method for deriving EILs that protect aquatic ecosystems
Schedule B5c—Guideline on Ecological Investigation Levels for Arsenic, Chromium (III), Copper, DDT, Lead, Naphthalene, Nickel and Zinc
Appendix A Raw toxicity for arsenic
Appendix B Raw toxicity for chromium (III)
Appendix C Raw toxicity for copper
Appendix D Explanation of the selection of the soil properties that control the added contaminant limits for copper
Appendix E Raw toxicity for DDT
Appendix F Raw toxicity for lead
Appendix G Raw toxicity for naphthalene
Appendix H Raw toxicity for nickel
Appendix I Raw toxicity for zinc
Schedule B6—Guideline on the Framework for Risk‑Based Assessment of Groundwater Contamination Schedule B7—Guideline on derivation of health‑based investigation levels
Appendix A1 Derivation of HILs for Metals and Inorganics
Appendix A2 Derivation of HILs for PAHs and Phenols
Appendix A3 Derivation of HILs for Organochlorine Pesticides
Appendix A4 Derivation of HILs for Herbicides and Other Pesticides
Appendix A5 Derivation of HILs for PCBs and PBDEs
Appendix A6 Derivation of HILs for Volatile Organic Carbon Compounds
Appendix B Equations for derivation of HILs and Interim HILs
Appendix C Derivation of HILs for Generic Land Uses
Appendix D Blood lead model assumptions
Schedule B8—Guideline on Community Engagement and Risk Communication Schedule B9—Guideline on Competencies and Acceptance of Environmental Auditors and Related Professionals
Page
1 Introduction 1
1.1Overview 1
1.2Prevention of site contamination 1
1.3Specialised assessments 1
1.4Acute hazards 1
1.5Mineralised areas 2
2 Derivation of investigation and screening levels 3
2.1Introduction 3
2.1.1Definitions 3
2.1.2Inappropriate use of investigation levels and screening levels 4
2.2Health investigation levels 4
2.3Interim HILs for volatile organic chlorinated compounds 5
2.4Health screening levels for petroleum hydrocarbon compounds 6
2.4.1Introduction 6
2.4.2HSL methodology 6
2.4.3Sub-slab to indoor air attenuation factor 7
2.4.4Petroleum fuel composition 8
2.4.5The Total Recoverable Hydrocarbons analytical method 8
2.4.6Petroleum hydrocarbon compounds and fractions 9
2.4.7Soil texture 9
2.4.8Land use 10
2.4.9Adjusting HSLs to site-specific circumstances 10
2.4.10Biodegradation 10
2.4.11Direct contact HSLs 11
2.4.12HSLs and multiple-lines-of-evidence approach 11
2.4.13Limitations of the HSLs 12
2.5Ecological investigation levels 13
2.5.1Introduction 13
2.5.2EIL methodology 13
2.5.3Land use 13
2.5.4Levels of protection 13
2.5.5Ecotoxicity data 13
2.5.6Depth of application 14
2.5.7Ambient background concentration 14
2.5.8Added contaminant limits 14
2.5.9Ageing of contamination and soil properties 15
2.5.10Determining site-specific EILs 15
2.6Ecological screening levels for petroleum hydrocarbon compounds 16
2.6.1Introduction 16
2.6.2ESL Methodology 16
2.6.3Depth of application 17
2.6.4Soil texture 17
2.6.5Fresh and aged contamination 17
2.7Sediment quality guidelines 17
2.8Groundwater investigation levels 17
2.9‘Management limits’ for petroleum hydrocarbon compounds 18
3 Application of investigation and screening levels 19
3.1Recommended process for assessment of site contamination 19
3.2Tier 1 assessment 19
3.2.1Comparison with investigation and screening levels 19
3.2.2Exceedence of Tier 1 investigation and screening levels 20
3.2.3Procedure if no generic investigation or screening levels are available 20
3.3Specific considerations for petroleum hydrocarbons 21
3.4Considerations for ecological assessment 22
3.4.1General 22
3.4.2Scope of ecological assessment 23
3.4.3Mobility of contaminants 23
3.5Considerations for groundwater assessment 24
3.6Aesthetic considerations 24
3.6.1Introduction 24
3.6.2Circumstances which would trigger an assessment of aesthetics 24
3.6.3Assessment process for aesthetic issues 25
4 Asbestos materials in soil 26
4.1Scope of the guidance 26
4.2Historical use of asbestos in Australia 26
4.3Work Health and Safety 26
4.4Terminology for asbestos contamination in soil 27
4.5Occurrence of asbestos contamination in soil 28
4.6Asbestos soil contamination and health risk 29
4.7Basis for health screening levels for asbestos in soil 29
4.8Health screening levels for asbestos in soil 29
4.9Process for assessment of asbestos contamination 30
4.10Determining asbestos in soil concentrations 30
4.11Assessment against asbestos screening levels and procedure for exceedences 33
5 Case Studies 35
6 Tabulated investigation and screening levels 47
7 Bibliography 75
8 Glossary 78
9 Shortened forms 81
1 Introduction
1.1 Overview
The purpose of site assessment is to determine the human health and ecological risks associated with the presence of site contamination and to inform any remediation or management plan to make the site fit for the current or proposed land use. The appropriate use of investigation levels is an integral component of the assessment process.
This Schedule provides a framework for the use of investigation and screening levels. The framework is based on a matrix of human health and ecological soil and groundwater investigation and screening levels and guidance for specific contaminants. The derivation of health-based investigation levels is outlined in Schedule B7, and the risk assessment methodologies are detailed in Schedule B4. Schedule B5a outlines a risk-based framework for site-specific ecological risk assessment. The derivation of ecological investigation levels is outlined in Schedule B5c and the methodology is detailed in Schedule B5b. Reference is also made to the derivation and use of health and ecological screening levels in site assessment.
The selection of the most appropriate investigation levels for use in a range of environmental settings and land use scenarios should consider factors including the protection of human health, ecosystems, groundwater resources and aesthetics. The development of a conceptual site model is an essential element of site assessment and should inform the selection of appropriate investigation and screening criteria. A balance between the use of generic soil, soil vapour and groundwater criteria and site-specific considerations is essential practice in site assessment.
1.2 Prevention of site contamination
The National Environment Protection (Assessment of Site Contamination) Measure 1999 (NEPM) does not provide guidance on prevention of site contamination. Owners and occupiers of sites on which potentially contaminating activities are occurring are subject to the environmental protection legislation applying in each jurisdiction. Legislation provides for appropriate controls on potentially contaminating sources, including licensing of industrial activities, to minimise emissions and its application is the principal strategy for prevention of soil and groundwater contamination.
1.3 Specialised assessments
Specialised forms of assessment are required for sites affected by the following types of contaminants:
· radioactive substances
· unexploded ordnance
· pathogenic materials and waste
· explosive gas mixtures.
In situations where these materials occur on a site under assessment, guidance should be sought from the relevant jurisdictional environmental or health authority for assessment requirements. While the general principles of site assessment are applicable to these contamination types, compliance with specialised safety protocols and assessment guidance is essential to ensure protection of human health and the environment.
1.4 Acute hazards
Risk of explosion or other acute exposure hazards should be addressed immediately and are not within the scope of this guidance document.
Health effects can be broadly separated into acute and chronic effects. The distinction between acute and chronic exposure relates to the duration of exposure and the timing of onset of any health effects. Acute health effects occur within minutes, hours or days of a relatively short period of exposure, while chronic health effects occur as a result of prolonged or repeated exposures over many days, months or years and symptoms may not be readily apparent.
Most contaminated land assessments will be focussed on chronic health effects; however, some sites may pose acute risks. Assessment of sites with petroleum hydrocarbon contamination will need to consider the potential for acute health risks and the risk of fire and explosion from the presence of light non aqueous phase liquids (LNAPLs).
Work health and safety issues should be considered for all sites and managed according to national and jurisdictional legislative requirements.
1.5 Mineralised areas
High levels of metals, metalloids and asbestos can be associated with ore bodies. Soils in mining areas may contain elevated levels of these materials due to natural mineralisation. Some urban areas may be affected by asbestos and various elements including lead, copper, zinc, cadmium and arsenic from the ore bodies, as well as activities associated with mining, smelting and metallurgical industries.
Due to the health concerns associated with asbestos, affected areas should be effectively managed in the short and long term. Naturally occuring asbestos is most likely encountered during exploration and mining operations. Management measures similar to those for free fibre usually apply.
These environments may require specific prevention measures and community awareness programs when human settlement has occurred, to enable appropriate precautions to be taken (for example, preventing the use of potentially contaminated soil or fill from a mining site for growing vegetables in the home garden, constructing driveways or filling private land and publicly accessible areas). Public information about preventing exposure to mineralised or contaminated soil is an essential component of public health programs to minimise community exposure to these contaminants.
Depending on the nature of the contaminants associated with the mining (or quarrying) activity, contaminated soil may be only one of a number of exposure pathways. Local health issues may be more effectively targeted by monitoring key community health parameters such as blood lead or by environmental monitoring of ambient air quality and dust.
2 Derivation of investigation and screening levels
2.1 Introduction
The purpose of this Schedule is to describe soil, soil vapour and groundwater criteria that can be used to evaluate potential risks to human health and ecosystems from site contamination. Investigation and screening levels are provided for commonly encountered contaminants which are applicable to generic land use scenarios and include consideration of, where possible, the soil type and the depth of contamination.
Investigation levels and screening levels are applicable to the first stage of site assessment. The selection and use of investigation and screening levels should be considered in the context of the iterative development of a conceptual site model (CSM) (refer Schedule B2 Section 4) to ensure appropriate evaluation of human health and ecosystem risks.
Site assessment should include consideration of all relevant human exposure pathways, ecological risks and risk to groundwater resources.
2.1.1 Definitions
Investigation levels and screening levels are the concentrations of a contaminant above which further appropriate investigation and evaluation will be required.
Investigation and screening levels provide the basis of Tier 1 risk assessment. A Tier 1 assessment is a risk-based analysis comparing site data with generic investigation and screening levels for various land uses to determine the need for further assessment or development of an appropriate management strategy. The application of investigation and screening levels is subject to a range of limitations.
Ecological investigation levels (EILs) have been developed for selected metals and organic substances and are applicable for assessing risk to terrestrial ecosystems. EILs depend on specific soil physicochemical properties and land use scenarios and generally apply to the top 2 m of soil. Further detail is provided in Section 2.5 and Schedule B5.
Ecological screening levels (ESLs) have been developed for selected petroleum hydrocarbon compounds and total petroleum hydrocarbon (TPH) fractions and are applicable for assessing risk to terrestrial ecosystems. ESLs broadly apply to coarse- and fine-grained soils and various land uses. They are generally applicable to the top 2 m of soil. Further detail on their use is provided in Section 2.6 and Warne (2010a, 2010b), available from the ASC NEPM Toolbox.
Groundwater investigation levels (GILs) are the concentrations of a contaminant in groundwater above which further investigation (point of extraction) or a response (point of use) is required. GILs are based on Australian water quality guidelines and drinking water guidelines and are applicable for assessing human health risk and ecological risk from direct contact (including consumption) with groundwater. Further information is provided in Section 2.8 and Schedule B6.
Health investigation levels (HILs) have been developed for a broad range of metals and organic substances. The HILs are applicable for assessing human health risk via all relevant pathways of exposure. The HILs are generic to all soil types and apply generally to a depth of 3 m below the surface for residential use. Site-specific conditions should determine the depth to which HILs apply for other land uses. Further detail is provided in Section 2.2 and Schedules B4 and B7.
Interim soil vapour health investigation levels (interim HILs) have been developed for selected volatile organic chlorinated compounds (VOCCs) and are applicable to assessing human health risk by the inhalational pathway. They have interim status pending further scientific work on volatile gas modelling from the sub-surface to building interiors for chlorinated compounds. Further detail on their use is provided in Section 2.3 and Schedule B4.
Health screening levels (HSLs) have been developed for selected petroleum compounds and fractions and are applicable to assessing human health risk via the inhalation and direct contact pathways. The HSLs depend on specific soil physicochemical properties, land use scenarios, and the characteristics of building structures. They apply to different soil types, and depths below surface to >4 m. Further detail on their use is provided in Section 2.4 and Friebel and Nadebaum (2011a, 2011b & 2011c).
‘Petroleum hydrocarbon management limits’ (‘management limits’) are applicable to petroleum hydrocarbon compounds only. They are applicable as screening levels following evaluation of human health and ecological risks and risks to groundwater resources. They are relevant for operating sites where significant sub-surface leakage of petroleum compounds has occurred and when decommissioning industrial and commercial sites. Further detail on their use is provided in Section 2.9, including factors to be considered in determining the depth to which they apply.
2.1.2 Inappropriate use of investigation levels and screening levels
Investigation and screening levels are not clean-up or response levels nor are they desirable soil quality criteria. Investigation and screening levels are intended for assessing existing contamination and to trigger consideration of an appropriate site-specific risk-based approach or appropriate risk management options when they are exceeded. The use of these levels in regulating emissions and application of wastes to soil is inappropriate.
The use of investigation and screening levels as default remediation criteria may result in unnecessary remediation and increased development costs, unnecessary disturbance to the site and local environment, and potential waste of valuable landfill space. Similarly, the inclusion of an investigation and screening level in this guidance should not be interpreted as condoning discharges of waste up to these levels.
2.2 Health investigation levels
The health risk assessment methodology that forms the basis for calculation of HILs is provided in Schedule B4. The derivation of the HILs is presented in Schedule B7 (and appendices) and uses the Australian exposure factor guidance (enHealth 2012). The derivation of the HILs is illustrated by two worked examples for cadmium and benzo(a)pyrene (refer Schedule B7 Appendix B). The spreadsheet for calculating HILs is included in the ASC NEPM Toolbox ( HILs are listed in Table 1A(1), found at the end of this Schedule.
HILs are scientifically based, generic assessment criteria designed to be used in the first stage (Tier 1 or ‘screening’) of an assessment of potential risks to human health from chronic exposure to contaminants. They are intentionally conservative and are based on a reasonable worst-case scenario for four generic land use settings:
· HIL A - residential with garden/accessible soil (home grown produce <10% fruit and vegetable intake, (no poultry), also includes children’s day care centres, preschools and primary schools
· HIL B - residential with minimal opportunities for soil access includes dwellings with fully and permanently paved yard space such as high-rise buildings and flats
· HIL C - public open space such as parks, playgrounds, playing fields (e.g. ovals), secondary schools and footpaths. It does not include undeveloped public open space (such as urban bushland and reserves) which should be subject to a site-specific assessment where appropriate
· HIL D - commercial/industrial such as shops, offices, factories and industrial sites.
The land use scenarios are described in detail in Section 3 of Schedule B7. To make generic estimates of potential human exposure to soil contaminants, scientifically based assumptions are made about the environment, human behaviour, the physicochemical characteristics of contaminants, and the fate and transport of contaminants in soil within each of these land use categories. The HILs are derived by integrating these exposure estimates with toxicity reference values, that is, tolerable daily intakes (TDI), acceptable daily intakes (ADI), and reference doses (RfD), to estimate the soil concentration of a substance that will prevent exceedence of the toxicity reference value under the defined scenario. The toxicity reference values are generally based on the known most sensitive significant toxicological effect. Where toxicity reference values come from multiple sources, their underlying assumptions, defaults and science policy should be compatible and generally similar.
HILs establish the concentration of a contaminant above which further appropriate health investigation and evaluation will be required. Levels slightly in excess of the HILs do not imply unacceptability or that a significant health risk is likely to be present. Exceeding a HIL means further investigation is required and not ‘risk is present, clean-up required’.
The HILs are referred to by regulators, auditors and consultants in the process of assessing soil contamination. HILs apply generally to the top 3 m of soil for residential use. Site-specific conditions should determine the depth to which HILs apply for other land uses.
HILs are not intended to be clean-up levels. The decision on whether clean-up is required, and to what extent, should be based on site-specific assessment triggered by an exceedence of the HIL. Health risk assessment is the primary driver for making site decisions. Other considerations such as practicality, timescale, effectiveness, cost, sustainability and associated ecological risk assessment are also relevant.
2.3 Interim HILs for volatile organic chlorinated compounds
Interim HIL soil vapour levels for specific volatile organic chlorinated compounds (VOCCs) have been developed (see Table 1A(2) at the end of this Schedule) to assess the vapour inhalation pathway (also known as the ‘vapour intrusion’ pathway when referring to indoor exposure). The derivation of the interim HILs is presented in Schedule B7 and Appendix A6. The methodology employs a simple though conservative approach using an attenuation factor that relates the concentration of a volatile contaminant in indoor air to the concentration in soil gas immediately below a building foundation slab.
The interim HIL values derived for volatile compounds are driven by the vapour intrusion pathway (that contributes >99% of the total risk when all pathways are considered). However, it is noted that there are limitations and uncertainties associated with the assessment of volatile contaminants on the basis of soil concentrations. As these limitations are significant for volatile organic chlorinated compounds, interim HILs for soil have not been derived. Rather it is recognised that where indoor/ambient air data cannot be collected (or the data is adversely affected by background sources), the most relevant approach to the assessment of this pathway is through the collection of soil vapour data. On this basis, interim HILs have been developed for soil vapour.
The interim HILs provide Tier 1 guidance for health risks from soil contamination sources and groundwater plumes associated with this group of compounds. The values may be applied for general site assessment and sub-slab environments for evaluation of potential health risks for the 0-1 m sub-slab profile. The interim HILs broadly apply to the same generic land use categories as do the HILs, though the values for residential A and B are combined as they are based on the same exposure conditions (i.e. the same amount of time spent indoors) for the vapour inhalation pathway. In addition, secondary school buildings should be treated as residential for the purposes of evaluating risks from vapour intrusion.
Biodegradation of VOCCs has not been included in the development of the interim HILs. The biodegradation approach developed for petroleum hydrocarbons (refer Section 2.4.10) is not applicable to the degradation of VOCCs as the mechanism by which degradation occurs is different for most chlorinated hydrocarbons compared with petroleum hydrocarbons.
2.4 Health screening levels for petroleum hydrocarbon compounds
2.4.1 Introduction
Site contamination by petroleum hydrocarbon compounds is frequently encountered. The complex mixtures of aliphatic and aromatic compounds that comprise petroleum hydrocarbon products present human health concerns predominantly through inhalation of vapours from contaminant sources and by direct contact with affected soils and groundwater. Assessment of petroleum impacts should include evaluation of risks via the groundwater pathway (e.g. consumption of contaminated groundwater that is not considered in the HSLs), the risk to groundwater resources and appropriate consideration of aesthetics. The application of relevant ecological and ‘management’ criteria for petroleum compounds is discussed in Sections 2.6 and 2.9.
Health Screening Levels (HSLs) for various petroleum hydrocarbon compounds were developed by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE). The principal reference for the HSL methodology is Friebel and Nadebaum (2011a). In addition to the documentation of the methodology, a detailed application report (Friebel & Nadebaum 2011b) and a sensitivity analysis of the main parameter inputs ((Friebel & Nadebaum 2011c) are available.
Predictive modelling of sub-surface vapour movement in soil and penetration of building structures is a field of intensive data collection and research. The most recent research and derivation approaches adopted in developed international jurisdictions have been considered and adapted, as far as is practicable, for Australian conditions, to derive Tier 1 screening criteria for evaluating human health risk from petroleum hydrocarbons.
The HSLs’ development was guided by a project advisory group with health, environmental, assessment and remediation, petroleum industry and regulatory expertise. A specialised technical working group provided technical support and review throughout the development process. The HSL methodology was subject to international peer review during its development.
Copies of the technical reports can be found in the ASC NEPM Toolbox. Additional information on the development phases of the project, including responses to peer review comments, can be found on the CRC CARE website:
align="center">Assessment of vapour risks is a specialist area. It is the responsibility of contaminated land professionals to become familiar with the limitations of the HSLs and their correct application in site assessment (Friebel & Nadebaum 2011a, 2011b, 2011c).
2.4.2 HSL methodology
The HSLs were developed to be protective of human health by determining the reasonable maximum exposure from site sources for a range of situations commonly encountered on contaminated sites. As there are many parameter inputs to the methodology, very conservative assumptions have not been made for every parameter as this would result in an unrealistic result arising from the compounding of conservatism. Typically the parameter values selected correspond to the mean or median of the available information, with some parameters corresponding to the 95th percentile. For further information on the rationale for each parameter selected, refer to Friebel and Nadebaum (2011a).
The HSLs apply to the same land use settings as for the interim HILs for VOCCs and include additional consideration of soil texture and depth to source to determine the appropriate soil, groundwater and soil vapour criteria for the exposure scenario. As with all modelling approaches, the assumptions made regarding the exposure scenario limit the extent of their reasonable application. The main limitations for the HSLs are summarised in Section 2.4.13.
HSLs for soil (Table 1A(3)), groundwater (Table 1A(4)) and soil vapour (Table 1A(5)) apply to exposure to petroleum hydrocarbons through the dominant vapour inhalation exposure pathway only. Direct contact HSLs have been developed for the incidental soil ingestion, dermal and inhalation exposure pathways. The direct contact HSLs are generally not the risk drivers for further site assessment for the same contamination source as the HSLs for vapour intrusion. Direct contact exposure should be considered where relevant to the site-specific scenario e.g. an external source in near-surface soils in a residential or recreational setting. Further details can be found in Friebel and Nadebaum (2011a, 2011b, and 2011c).
There are many site-specific, soil-specific and building-specific variables that affect the level of the HSLs and these factors should be considered in the site assessment. Detailed information on the model inputs and assumptions (for example, soil properties, sub-slab attenuation factor, organic carbon content, chemical properties, building parameters) and overall limitations are provided in Friebel and Nadebaum (2011a). A sensitivity analysis was used to evaluate the effect that these parameters have on the derived HSLs (Friebel & Nadebaum 2011c).
A review of vapour models was undertaken by CSIRO as a precursor project to the development of the HSLs (Davis et al. 2009c). As a result of this review, a modified Johnson and Ettinger vapour exposure model (US EPA 2004) was selected to derive HSLs for the vapour inhalation pathway. The model has been used assuming a finite source for soils equivalent to a source thickness of 2 m which avoids the extreme conservatism associated with assuming an infinite source and reflects empirical field observations. For groundwater and soil vapour, an infinite source (i.e. steady state model) has been assumed as replenishment of vapours may occur by contaminated groundwater flowing beneath the site.
It is noted that the Johnson and Ettinger model and other similar vapour intrusion models do not adequately address vapour risk issues where there are preferential vapour migration pathways, where the building structure extends into a saturated contaminated zone (i.e. into the groundwater table) or where biodegradation is of significance (see section 2.4.10 for further information).
The soil and groundwater HSLs are based on three-phase equilibrium theory and soil vapour is limited by the maximum solubility limit of the chemical in the soil pore water phase or the groundwater. The soil saturation concentration of a particular contaminant is the condition where pore water is at its solubility limit and soil vapour is at the maximum vapour concentration. When a calculated HSL in soil or groundwater exceeds this limit, the vapour in the soil or above groundwater cannot result in an unacceptable vapour risk and is denoted as NL (not limiting) in the HSL tables (Tables 1 A(3) - 1A(5)). Soil vapour HSLs are based on the vapour pressures of individual chemicals. Calculated soil vapour HSLs that exceed the possible maximums are similarly denoted as NL.
The HSLs have been derived using accepted approaches to assessment for non threshold (cancer) risk and threshold (non-cancer) risk. Exposure factors for the individual carcinogenic and non-carcinogenic compounds of concern were derived from a near-final draft of enHealth (2012).
2.4.3 Sub-slab to indoor air attenuation factor
Unlike the derivation of the soil vapour interim HILs, the attenuation factor adopted for petroleum hydrocarbon compounds is not used directly to calculate indoor air concentrations from soil gas concentrations (or vice versa); rather it is used to calculate one of the many input parameters (advective air flow) in the Johnson & Ettinger model. For further information refer to section 7.3.2 of Friebel and Nadebaum (2011a).
As for other input parameters, the selected value for the attenuation factor is based on a reasonable assumption rather than the maximum possible exposure and is equivalent to the median of the US EPA 2008 attenuation factor database (US EPA 2008) and lies within the 75th to 95th percentiles of the updated database published in 2012 (US EPA 2012). The selected value of 0.005 was considered to represent the upper value not affected by indoor air sources, background air or other confounding factors.
2.4.4 Petroleum fuel composition
The soil saturation and water solubility limits used in the derivation of the HSLs assume a fixed fuel composition based on fresh petrol and diesel fuels typical of those available in Australia. The HSLs may be applied to other fuel types (e.g. kerosene, aviation fuel and fuel oil) providing that the aliphatic/aromatic speciation is similar to that assumed in the derivation of the HSLs (80:20). Further information on these fuel types can be found in TPHCWG (1998). There are a number of fuel additives, such as MTBE and ethanol, for which HSLs have not been derived. Where these are identified as potential contaminants of concern, then a site-specific risk assessment for these chemicals should be considered.
The HSLs apply to petroleum contamination sources and are not applicable to pure compound solvents, as solubility limits incorporated into the HSLs were derived based on typical petrol and diesel fuel mixtures. Equivalent values to the HSLs applicable to pure compounds (rather than fuel mixtures) are available in Friebel and Nadebaum (2011a Appendix C).
2.4.5 The Total Recoverable Hydrocarbons analytical method
The Total Recoverable Hydrocarbons (TRH) method is recommended for the analysis of petroleum hydrocarbon compounds in soil. Detailed information is provided in Schedule B3.
The term TRH is equivalent to the previously used total petroleum hydrocarbons (TPH) and represents extracted biogenic (biological) and petrogenic (petroleum) hydrocarbons by selected solvents. The TRH analysis is non-specific and will extract organic compounds such as ethanol, biodiesel compounds (esterised long chain fatty acids), organic acids, sterols and n-alkanes from plant waxes, as well as petroleum hydrocarbons. The sample extraction process may also extract other industrial organic chemicals. When used in the context of a screening assessment for petroleum hydrocarbon contamination, TRH analyses are likely to be conservative when non-petroleum compounds are present.
The potential for inclusion of non-petroleum compounds in the results may be relevant for site-specific assessment of petroleum hydrocarbon contamination. For example, the TRH analytical results may be overly conservative if soil organic matter is unusually high, for example from heavy applications of mulch, manure, compost or other natural organic material, or the presence of other synthetic organic compounds which are extractable in the analytical process. To assess potential false positive results, it is recommended that equivalent soil from the site, unaffected by petroleum hydrocarbon contamination, is analysed for comparison.
Where there is reasonable doubt as to the nature of the contamination, the sample may be subjected to a silica gel clean-up and analysed by gas chromatography mass spectrometry (GC-MS) (or other appropriate analytical method) to assist with the identification of contamination of petroleum origin. In these cases, an analyst report should be obtained with an interpretation of the chromatogram and the nature and extent of contamination present in the sample.
2.4.6 Petroleum hydrocarbon compounds and fractions
HSLs have been developed for BTEX and naphthalene plus four carbon chain fractions based on the fractions adopted in the Canada-wide standard for petroleum hydrocarbons (PHC) in soil (CCME 2008). The fractions are listed in Table 1 below:
Table 1. HSL fractions and corresponding equivalent carbon range
Fraction number Equivalent carbon number range F1 C6 – C10 F2 >C10 – C16 F3 >C16 – C34 F4 >C34 - C40 The HSLs are provided in Tables 1A(3) – 1A(5)).
BTEX results should be subtracted from the TRH C6 – C10 analytical results for comparison with the HSL for F1. Likewise, naphthalene should be subtracted from >C10 – C16 for comparison with the HSL for F2.
Chemicals in the >C16-C34 and >C34-C40 fractions are non-volatile and therefore not of concern for vapour intrusion, however, exposure can be via direct contact pathways (dermal contact and incidental ingestion and inhalation of soil particles). Direct contact HSLs for these fractions can be found in Friebel and Nadebaum (2011a).
2.4.7 Soil texture
HSLs for soil, groundwater and soil vapour have been developed for sand, silt and clay soils based on the US soil texture classification system (Friebel & Nadebaum 2011a). The HSLs assume a uniform soil profile and the soil texture making up the greatest proportion of the soil profile should be used in selecting the appropriate HSLs (Friebel & Nadebaum 2011a and 2011b).
For Tier 1 soil assessment, the HSL classifications of sand, silt and clay may be broadly applied to the soil texture classification in Table A1 of Standard AS 1726.
Table 2. HSL soil classification and equivalent soil classification in AS 1726
HSL soil classification AS 1726 Equivalent Sand Coarse-grained soil Silt Fine-grained soil - silts and clays (liquid limit <50%) Clay Fine-grained soil - silts and clays (liquid limit >50%) Where there is reasonable doubt as to the appropriate soil texture to select, either a conservative selection should be made (i.e. select coarsest applicable grain size such as sand) or laboratory analysis carried out to determine particle size and hence soil texture sub-class (refer Section 7.3.1 in Friebel and Nadebaum 2011b). If particle size analysis is undertaken then laboratory measurement of additional parameters used in site-specific risk assessment (such as soil moisture content, organic carbon content and saturation porosity - refer Friebel & Nadebaum 2011b for further information) could also be considered if further assessment is possible. If laboratory measurement is undertaken, sufficient samples should be obtained and analysed to determine a representative value for each soil unit of interest for the assessment.
2.4.8 Land use
The HSLs are derived for various depths to source and for the same generic land uses as for the HILs (described in detail in Schedule B7). The values for residential A and B are combined in the HSL tables as they are based on the same exposure conditions for the vapour inhalation pathway (i.e. the same amount of time spent indoors).
The HSLs are applicable to ground floor land use. If the vapour exposure is acceptable at ground level, it can be assumed that it is also acceptable for floors above ground level. For multistorey buildings where non-residential uses (e.g. car parking or commercial use) exist in a basement or at ground level, then land use category D (commercial/industrial) should be applied.
Any sensitive land uses e.g. childcare or day care centre will require application of HSL A irrespective of their planning zoning. Secondary school buildings (as opposed to secondary school grounds) should also be assessed using HSL A.
2.4.9 Adjusting HSLs to site-specific circumstances
The HSL methodology enables parameter inputs to be changed to more accurately reflect local soil, site or building conditions. Input parameters should be selected to be representative of long-term stable conditions and appropriate to the soil unit/aquifer of concern e.g. moisture content may vary seasonally and may also be different beneath buildings. Where insufficient data is available to establish a representative value, a conservative approach should be taken, for example, by assuming dry soil moisture conditions in sand. The HSL application and sensitivity documents (Friebel & Nadebaum 2011b, 2011c) provide further details. Jurisdictions may also adopt policies to vary the HSLs to account for local conditions.
For example, air exchange rates have been set at 0.6 building volumes/hr which may not be appropriate for buildings designed for tropical and cold climates. Similarly, soil moisture has a significant effect on penetration of volatiles into buildings.
The HSL derivation has assumed a slab-on-ground construction. Elevated buildings on concrete supports or timber poles with no direct floor contact with the soil and clear underfloor ventilation are at lower risk of penetration of volatiles and the risk decreases with the elevation of the floor above ground. The state of the slab will require consideration if it has deteriorated, as cracks can act as preferential pathways.
2.4.10 Biodegradation
Recent research on underslab biodegradation of petroleum hydrocarbon contamination is reported in Davis et al. (2009a and 2009b). This research identified that the following site conditions are conducive to biodegradation of petroleum hydrocarbon compounds in the sub-surface:
· the presence of oxygen at concentrations greater than 5% in soil vapour at a depth 1 m below the surface immediately adjacent to the concrete slab
and
· a maximum slab width of less than 15 m, with oxygen access on both sides of the slab for Tier 1 screening purposes. A distance of 7-8 m from the exposed soil at the slab boundary is considered the maximum lateral underslab penetration of oxygen.
It is noted that the measurement of oxygen in the soil profile can be difficult and care should be taken when using this data to support biodegradation.
If these conditions are fulfilled, biodegradation factors can be applied to the vapour intrusion HSLs as follows:
· factor of x10 for depths to source of 2 to <4 m and
· factor of x100 for depths to source of 4 m and greater where the vapour source strength is 100 mg/L (100,000 mg/m3) or less.
The biodegradation factors above are not applicable for depths of less than 2 m. For the purpose of this NEPM, assessment including biodegradation of petroleum hydrocarbons is considered a Tier 1 activity.
Application of the biodegradation factors described above may result in levels of TPH, BTEX and naphthalene that are acceptable for human health risk from the vapour exposure pathway for the specific land use but which may not be acceptable for protection of the environment or water resources or from an aesthetics perspective. Site results should be considered with reference to relevant ecological and ’management levels‘(refer Sections 2.5 and 2.9) which may become the predominant risk driver. Management levels should be applied after human health, ecological risks and risks to groundwater resources have been assessed.
2.4.11 Direct contact HSLs
Direct contact HSLs have been developed for exposure through dermal contact, incidental oral ingestion and dust inhalation and then combined as a single HSL for direct contact with soil (Friebel & Nadebaum, 2011a). For most site assessments, the direct contact HSLs are unlikely to become drivers for further investigation or site management as the values are significantly higher than most other soil screening levels and consequently have not been included here. There are situations where the combined vapour and direct contact pathways can make a difference to the outcome of the assessment. For further information on considering combined vapour and direct contact exposure, refer to Section 3.3 of Friebel and Nadebaum (2011b). The combined HSLs for direct contact can be found in Appendix A of Friebel & Nadebaum (2011a).
Contamination at the levels of the direct contact HSLs are likely to present unacceptable aesthetic considerations which should be addressed in accordance with the discussion in Section 3.6. Exposure to a contaminated surface (other than of short and temporary duration) at the levels of the direct contact HSLs may also cause an unacceptable short-term vapour exposure risk.
2.4.12 HSLs and multiple-lines-of-evidence approach
For an assessor to conclude that the vapour intrusion/emission pathways are unlikely to be active or to present a significant risk, the assessor should undertake a multiple-lines-of-evidence approach. This requires the assessor to present several reasoned lines of evidence as to why the pathway is considered inactive or is unlikely to present a significant risk.
The soil and groundwater HSLs provide the principal assessment criteria for open excavations (such as tank removal operations) while greater emphasis is placed on soil vapour HSLs in assessing potential vapour intrusion risks from hydrocarbon sources and groundwater plumes adjacent to or under buildings. In general, evaluating all contaminant phases will provide greater confidence in the outcomes of the site assessment.
Soil vapour measurements can provide a more accurate representation of vapour risks (compared with the soil and groundwater HSLs), depending on site-specific conditions e.g. where soil vapour can be measured directly under conditions that are relevant to the future or continuing use of the site. In high moisture conditions, however, such as occur within the capillary fringe or as a result of seasonal watertable fluctuations, it is not possible to obtain reliable soil vapour readings. In these conditions, consideration may be given to obtaining vapour headspace readings from appropriately constructed groundwater monitoring wells fitted with a soil vapour monitoring cap that seals the groundwater well from the atmosphere.
Soil vapour measurements are also preferred where contaminated groundwater is present at less than 2 m below the ground or basement foundation, though in fine-grained soils the ability to obtain soil vapour measurements may be constrained by moisture conditions, as the thickness of the capillary fringe increases as the soil texture decreases.
Where the watertable rises seasonally to intersect basements or building foundations, indoor air measurements will be required to assess vapour risk. The assessment approach may also include soil vapour measurements taken in the dry season as part of a multiple-lines-of-evidence approach.
Additional information on vapour assessment and the multiple-lines-of-evidence approach is provided in Section 9.2 of Schedule B2 and Friebel and Nadebaum (2011a, 2011b).
2.4.13 Limitations of the HSLs
As with all generic screening levels, actual site-specific conditions may mean that the assumptions underpinning the derivation of the screening levels are not valid for the site and consequently a site-specific assessment will be required. The principal limitations applicable to the HSLs are listed in Table 3 below, together with suggested alternative assessment approaches.
Immediate action should be taken where potentially explosive or acutely toxic gas concentrations are present in buildings or in-ground services (e.g. utility trenches, sumps or drains) connecting a vapour source to a building. Emergency management actions, such as relocation of building occupants, should be implemented as necessary.
Table 3. Site scenarios where the application of the HSLs is limited and possible alternative assessment approaches
Site scenario Alternative assessment approach The identified contamination has an atypical petroleum composition
Site-specific risk assessment including assessment of cumulative effects of chemical constituents Contaminated groundwater or LNAPL is entering or is in contact with a basement or building foundation Consider indoor air sampling Depth to groundwater impact is less than 2 m Consider soil vapour measurements for vapour intrusion The impacted soil source thickness is significantly greater than 2 m
HSLs may be conservative for thinner soil sources. For thicker soil sources, refer to Section 2.4.7 of the HSLs application document (Friebel & Nadebaum 2011b) A preferential migration pathway is present that could connect a vapour source to a building interior Site-specific assessment
Hydrocarbon odour present in buildings or in-ground services (not attributable to an indoor or ambient source) which indicates an active preferential migration pathway and potentially an immediate human health risk Consider indoor air sampling or immediate action in the case of strong hydrocarbon odours 2.5 Ecological investigation levels
2.5.1 Introduction
Ecological investigation levels (EILs) for the protection of terrestrial ecosystems have been derived for common contaminants in soil based on a species sensitivity distribution (SSD) model developed for Australian conditions. EILs have been derived for As, Cu, CrIII, DDT, naphthalene, Ni, Pb and Zn.
Schedule B5a provides detailed guidance on the framework for ecological risk assessment. The methodology for deriving EILs is described in Schedule B5b and the detailed derivations of EILs for As, Cu, CrIII, DDT, naphthalene, Ni, Pb and Zn are presented in Schedule B5c. A spreadsheet, which may be used for calculating site-specific EILs is included in the ASC NEPM Toolbox.
2.5.2 EIL methodology
The detailed methodology, incorporated in Schedule B5b, was developed by CSIRO using data from various Australasian databases, the Australian National Biosolids Research Program and supplemented by data from the US EPA ecotoxicology database where necessary. The methodology is based on an SSD approach, which considers the physicochemical properties of soil and contaminants and the capacity of the local ecosystem to accommodate increases in contaminant levels (referred to as the ‘added contaminant limit’ or ACL) above ambient background. Where insufficient data is available for the SSD method to be used, a more conservative method using an assessment factor approach may be adopted.
The EILs are derived for specified levels of percentage species protection depending on land use. The approach is analogous to the methodology used for derivation of the Australian water quality guidelines (ANZECC & ARMCANZ 2000).
2.5.3 Land use
EILs have been developed for three generic land use settings:
· areas of ecological significance
· urban residential areas and public open space
· commercial and industrial land uses.
An area of ecological significance is one where the planning provisions or land use designation is for the primary intention of conserving and protecting the natural environment. This would include national parks, state parks, wilderness areas and designated conservation areas.
Urban residential/public open space is broadly equivalent to the HIL A, HIL B and HIL C land use scenarios (see Section 2.2 and Schedule B7).
EILs are not applicable to agricultural soils, which need evaluation in relation to crop toxicity, plant contaminant uptake and detailed consideration of soil type.
2.5.4 Levels of protection
The protection levels for the generic land use settings are:
· 99% for areas of ecological significance
· 80% for urban residential areas and public open space
· 60% for commercial and industrial land uses.
These protection levels are increased by 5% when biomagnification may occur (refer Schedule B5b).
2.5.5 Ecotoxicity data
The NEPM has adopted lowest observed effect concentration (LOEC) or effective concentration 30% (EC30) data to derive EILs for the land use scenarios.
The LOEC is the lowest concentration used in a toxicity test that causes a toxic effect that is significantly different from the control. EC30 data is the concentrations of contaminants that cause an effect on 30% of the test group of an organism after a specified exposure time. The data is drawn from a range of species to derive individual EILs.
For further information see Schedule B5b.
2.5.6 Depth of application
EILs apply principally to contaminants in the top 2 m of soil at the finished surface/ground level which corresponds to the root zone and habitation zone of many species. In arid regions, where the predominant species may have greater root penetration, specific considerations may result in their application to 3 m depth.
2.5.7 Ambient background concentration
The methodology assumes that the ecosystem is adapted to the ambient background concentration (ABC) for the locality and that it is only adding contaminants over and above this background concentration which has an adverse effect on the environment.
The ABC of a contaminant is the soil concentration in a specified locality that is the sum of the naturally occurring background level and the contaminant levels that have been introduced from diffuse or non-point sources by general anthropogenic activity not attributed to industrial, commercial, or agricultural activities, for example, motor vehicle emissions. Methods to estimate background levels are provided in Schedule B5b.
Three methods for determining the ABC are presented in Schedule B5b. The preferred method is to measure the ABC at an appropriate reference site. This approach is essential in areas where there is a high naturally occurring background level such as will occur in mineralised areas.
In other situations where an appropriate reference site cannot be determined, the method based on urban metal levels in Olszowy et al. (1995) or the method from Hamon et al. (2004) may be used.
In the method of Hamon et al. (2004), the ABC varies (depending on the element) with the soil iron and/or manganese concentration; for example, the ABC for zinc varies from
3 to 62mg/kg in soils with soil iron concentrations between 0.1% and 20%. Alternatively, ABCs for old and new suburbs and high and low traffic areas for New South Wales, Queensland, South Australia and Victoria for Zn, Cu, Ni, Pb, and CrIII are included in Schedule B5b and are derived from Olszowy et al. (1995). Values for new suburbs would be appropriate to use for new suburbs or in areas with no known history of contamination for that metal. In old-established urban areas (i.e. suburbs more than 20 years old), it would be appropriate to use the 25th percentile of the ABC values from Olszowy et al. (1995).In some situations the ABC may be comparatively low and have a minor effect on the magnitude of the site EIL.
2.5.8 Added contaminant limits
An added contaminant limit (ACL) is the added concentration (above the ABC) of a contaminant above which further appropriate investigation and evaluation of the impact on ecological values is required. The EIL is derived by summing the ACL and the ABC.
ACLs are based on the soil characteristics of pH, CEC and clay content. Empirical relationships that can model the effect of these soil properties on toxicity are used to develop soil-specific values. These soil-specific values take into account the biological availability of the element in various soils. In this approach different soils will have different contaminant EILs rather than a single generic EIL for each contaminant.
ACLs apply to chromium III (CrIII), copper (Cu), nickel (Ni) and zinc (Zn) for site-specific EIL determination. The soil properties to be determined for each relevant soil type at the site, are shown in Table 4 below.
Table 4: Soil properties to be measured for site-specific derivation of ACLs for CrIII, Cu, Ni and Zn
Soil physicochemical property CrIII Cu Ni Zn pH P CEC P P P % clay P Insufficient data was available to derive ACLs for arsenic (As), DDT, lead (Pb) and naphthalene. As a result, the derived EILs are generic to all soils and are presented as total soil contaminant concentrations in Tables 1B(4) and 1B(5).
2.5.9 Ageing of contamination and soil properties
In general the toxicity of soil contaminants (both organic and inorganic) will reduce or age over time to a lower and more stable level by binding to various soil components and decreasing their biological availability. Hence, toxicity can be affected by the physicochemical or chemical properties of the soil including clay content, cation exchange capacity (CEC) measured in centi-mole charge/kg (cmolc/kg), pH, iron and organic carbon content.
For the purposes of EIL derivation, a contaminant incorporated in soil for at least two years is considered to be aged for the purpose of EIL derivation. The majority of contaminated sites are likely to be affected by aged contamination. Fresh contamination is usually associated with current industrial activity and chemical spills.
In some cases insufficient data on aged contamination was available to apply the EIL methodology, and where possible, ageing factors based on relevant studies have been applied to determine a soil value for aged contamination.
EIL determination for fresh contamination (that is, present for less than two years) for the relevant contaminants should be site-specifically determined by reference to the relevant tables in Schedule B5c.
2.5.10 Determining site-specific EILs
Detailed information on the derivation of the EILs is provided in Schedule B5c. The following section describes the steps that are taken to derive site-specific EILs. A spreadsheet is included in the ASC NEPM Toolbox which can also be used for calculating site-specific EILs.
A. EILs for Ni, Cr III, Cu, Zn and Pb aged contamination (>2 years)
Steps 1–4 below describe the process for deriving site-specific EILs for the above elements using Tables 1B(1) – 1B(4), which can be found at the end of this Schedule.
1. Measure or analyse the soil properties relevant to the potential contaminant of concern (see Table 4). Sufficient samples need to be taken for these determinations to obtain representative values for each soil type in which the contaminant occurs.
2. Establish the sample ACL for the appropriate land use and with consideration of the soil-specific pH, clay content or CEC. The ACL for Cu may be determined by pH or CEC and the lower of the determined values should be selected for EIL calculation. Note that the ACL for Pb is taken directly from Table 1(B)4.
3. Calculate the contaminant ABC in soil for the particular contaminant and location from a suitable reference site measurement or other appropriate method.
4. Calculate the EIL by summing the ACL and ABC:
EIL = ABC + ACL
B. EILs for As, DDT and naphthalene
EILs for aged contamination for DDT and naphthalene are not available and the adopted EIL is based on fresh contamination taken directly from Table 1B(5). The EILs for As, DDT and naphthalene are generic i.e. they are not dependent on soil type and are taken directly from Table 1B(5). Only EILs for fresh contamination are available for As, DDT and naphthalene due to the absence of suitable data for aged contaminants.
2.6 Ecological screening levels for petroleum hydrocarbon compounds
2.6.1 Introduction
Ecological screening levels (ESLs) are presented based on a review of Canadian guidance for petroleum hydrocarbons in soil and application of the Australian methodology (Schedule B5b) to derive Tier 1 ESLs for BTEX, benzo(a)pyrene and F1 and F2 (Warne 2010a, 2010b).
The Canadian Council of the Ministers of the Environment (CCME) has adopted risk-based TPH standards for human health and ecological aspects for various land uses in the Canada-wide standard for petroleum hydrocarbons (PHC) in soil (CCME 2008) (CWS PHC). The standards established soil values including ecologically based criteria for sites affected by TPH contamination for coarse- and fine-grained soil types.
The standard applies to the same four fractions (F1–F4) adopted for the HSLs (refer Section 2.4.5 of this Schedule).
2.6.2 ESL Methodology
The CWS PHC approach uses an SSD method and, when there is insufficient data for the SSD method, applies a weight-of-evidence approach to derive ecologically based ’Tier 1 eco soil contact‘ values for TPH fractions and specific compounds. The overall approach has similarities to the Australian EIL methodology by developing protective criteria based on EC25 toxicity for residential land use and EC50 for commercial/industrial land (cf. Australia EC30 and LOEC data).
The Australian EIL methodology was applied to the ecotoxicity data used to derive the Canadian F1 and F2 (eco soil contact) values (Warne 2010a) to produce comparable Tier 1 values for these fractions. Based on the data quality and applicability to the Australian environment, the derived values for F1 and F2 are adopted as moderate reliability ESLs (see Table 1B(6) at the end of this Schedule) and apply generically to fine- and coarse-grained soils.
Due to the limited ecotoxicity data for F3 and F4, the Australian methodology was not able to be applied. The data limitations were recognised in the Canadian guidance and an alternative weight-of-evidence approach was used to develop values for these fractions. Consequently, the adopted values for F3 and F4 (see Table 1B(6)) are considered low reliability ESLs for fine- and coarse-grained soils (Warne 2010a, 2010b).
A further review of Canadian soil quality guidelines was undertaken for BTEX and benzo(a)pyrene (Warne 2010b) and the Australian methodology applied to the ecotoxicological data as far as possible to derive equivalent ESLs. However, data limitations did not allow the full use of the EIL derivation methodology and the resulting values are adopted as low reliability ESLs in Table 1B(6). Values were derived using the Canadian data reduction methods, the Australian SSD method and employing the Australian levels of protection for various land uses.
ESLs for the adopted carbon fraction ranges are based on TRH analysis with F1 being obtained after subtraction of BTEX.
2.6.3 Depth of application
ESLs apply from the surface to 2 m depth below finished surface/ground level, which corresponds to the root zone and habitation zone of many species. In arid regions, where the predominant species may have greater root penetration, specific considerations may result in their application to 3 m depth.
2.6.4 Soil texture
The ESLs are applicable to coarse and fine textured soils equivalent to coarse-grained soils and fine-grained soils in Table A1 of Standard AS 1726:1993. Conservative Tier 1 values (i.e. values for coarse soils) should be applied where site-specific textural information is not available.
2.6.5 Fresh and aged contamination
ESLs were derived on the basis of fresh contamination. GC-MS analysis and examination of the gas chromatogram output can assist in differentiating between fresh and aged TPH contamination.
While aged contamination is generally of less human health and environmental concern, sub-surface conditions can preserve some petroleum hydrocarbons for extended periods of time. Consideration should be given to the realistic risk of material being excavated and causing an exposure risk.
2.7 Sediment quality guidelines
Investigation and screening levels developed for soils should not be applied directly to the assessment of sediments.
Interim sediment quality guidelines (ISQG) are available in the Australian and New Zealand guidelines for Fresh and Marine Water Quality (ANZECC & ARMCANZ 2000) for a number of common metal, metalloid and organometallic contaminants and organics, principally PAHs and organochlorine pesticides (OCPs). The ISQG have limitations relating to the availability of appropriate ecotoxicology data and the small number of species on which they are based.
Reference to these guidelines, balanced by consideration of their limitations, may have application in the site-specific assessment of sites where contamination may impact aquatic receptors. Guidance on the sampling of sediments can be found in AS/NZS 5667.12:1999 Guidance on sampling of bottom sediments and Simpson et al. (2005).
2.8 Groundwater investigation levels
Site assessment should consider the risks from contaminated groundwater to all potential receptors on and off the site of origin and potential effects on groundwater resources.
The Groundwater investigation levels (GILs) are based on the Australian Water Quality Guidelines 2000 (AWQG), Australian Drinking Water Guidelines 2011 (ADWG) and Guidelines for Managing Risk in Recreational Waters 2008 (GMRRW). The GILs are adopted in the NEPM as investigation levels in the context of the framework for risk-based assessment of groundwater contamination (refer Schedule B6) i.e. levels above which further assessment is required.
The AWQG provide tabulated values based on percentage species protection for various aquatic environments and water uses. The appropriate settings for current and potential uses of groundwater need to be identified for the aquifer undergoing assessment. The guideline documents should be consulted for appropriate interpretation of guideline values, in consultation with relevant regulatory authorities if necessary.
Table 5. Groundwater environmental values and guidelines for their protection
Environmental value to be protected Guidelines to apply Raw drinking water source ADWG Agricultural use – stock watering AWQG Agricultural use – irrigation AWQG Fresh water aquatic ecosystem AWQG Marine water aquatic ecosystem AWQG Recreational use GMRRW The GILs provided in Table 1C at the end of this Schedule, define acceptable water quality for various contaminants at the point of use. Table 1C provides frequently used values for drinking water and protection of fresh and marine ecosystems. Additional GILs applicable to industrial use (aquaculture), agricultural use (stock watering and irrigation) and recreational waters are provided in the referenced documents.
The GMRRW recommend applying a multiplication factor of 10 to 20 to the ADWG for assessment of the acceptability of recreational water quality. GILs for other receptors should be obtained directly from the ‘primary industries’ section of the AWQG where relevant. Note that the recreational and aesthetics sections of the AWQG have been superseded by the GMRRW.
2.9 ‘Management limits’ for petroleum hydrocarbon compounds
In addition to appropriate consideration and application of the HSLs and ESLs, there are a number of policy considerations which reflect the nature and properties of petroleum hydrocarbons:
· formation of observable light non-aqueous phase liquids (LNAPL),
· fire and explosive hazards and
· effects on buried infrastructure e.g. penetration of, or damage to, in-ground services by hydrocarbons.
The CWS PHC includes ‘management limits’ to avoid or minimise these potential effects and these values have been adopted as interim Tier 1 guidance. The values are included in Table 1B(7) at the end of this Schedule. A site-specific assessment (Tier 2 or 3) may be preferred where relevant site-specific information is available.
Application of the management limits will require consideration of site-specific factors such as the depth of building basements and services and depth to groundwater, to determine the maximum depth to which the limits should apply. The management limits may have less relevance at operating industrial sites (including mine sites) which have no or limited sensitive receptors in the area of potential impact. When the management limits are exceeded, further site-specific assessment and management may enable any identified risk to be addressed.
The presence of site TPH contamination at the levels of the management limits does not imply that there is no need for administrative notification or controls in accordance with jurisdiction requirements.
Further information on the consideration of aesthetics with respect to petroleum hydrocarbons is included in Section 3.6.
3 Application of investigation and screening levels
3.1 Recommended process for assessment of site contamination
The recommended site assessment process is shown in Schedule A of the NEPM. Refer to Schedule B2 for guidance on site characterisation.
Before comparing site data with investigation and screening levels, it is important that sufficient and appropriate characterisation of the site is carried out to ensure that the comparison is both meaningful and relevant for assessing potential risks to human health and the environment.
A number of cases studies which illustrate the application of the investigation and screening levels in site assessment are included in Section 5 of this Schedule.
3.2 Tier 1 assessment
A Tier 1 (or screening level) assessment comprises a comparison of representative site data with generic investigation levels and/or screening levels for protection of human health and the environment, together with an assessment of any limitations on their use in relation to site-specific conditions. A Tier 1 assessment provides an initial screening of the data to determine whether further assessment is required.
Contaminated sites may contain multiple contaminants in soil and groundwater and the risk posed is affected by site characteristics such as soil properties and the depth to the contamination. The selection of the appropriate investigation and screening levels to apply at a particular site should be determined using professional judgement and with reference to the CSM.
3.2.1 Comparison with investigation and screening levels
No single summary statistic will fully characterise a site and appropriate consideration of relevant statistical measurements should be used in the data evaluation process and iterative development of the CSM (refer to Schedule B2, Section 4).
The preferred approach is to examine a range of summary statistics including the contaminant range, median, arithmetic/geometric mean, standard deviation and 95% upper confidence limit (UCL). Further information is provided in Section 11 of Schedule B2.
At the very least, the maximum and the 95% UCL of the arithmetic mean contaminant concentration should be compared to the relevant Tier 1 screening criteria. However, where there is sufficient data available, and it is appropriate for the exposure being evaluated, the arithmetic mean (or geometric mean in cases where the data is log normally distributed) should also be compared to the relevant Tier 1 investigation or screening level. The implications of localised elevated values (hotspots) should also be considered. The results should also meet the following criteria:
· the standard deviation of the results should be less than 50% of the relevant investigation or screening level, and
· no single value should exceed 250% of the relevant investigation or screening level.
The maximum observed contaminant concentration generally provides a conservative assessment of exposure because if estimated risks from the maximum concentrations are not of concern, then the site should be suitable for use under the CSM considered. However, a maximum concentration may not be representative of the source as a whole and may result in an overestimation or underestimation of risk if the data is extremely limited.
The mean contaminant concentration can be a suitable metric provided that it can be shown that it adequately represents the source being considered. It is important that small areas of high concentrations or hot-spots are not ignored by averaging with lower values from other parts of the site. The mean value may be more representative of the source as a whole than the maximum, and may provide a better estimation of the actual concentration that a population would be exposed to over a period of time.
7 Bibliography
ANZECC 1996, Polychlorinated Biphenyls Management Plan, Australian and New Zealand Environment and Conservation Council.
ASTM 2006, Standard E2348, Standard Guide for Framework for a Consensus-based Environmental Decision Making Process, ASTM International, West Conshohocken, PA, E2348-06, S 1992, ‘Remediation: level of disclosure and right to know’, Contaminated Land Remediation Technology Seminar: An International Perspective.
Bord, RJ & O’Connor, RF 1990, ‘Risk communication, knowledge and attitudes: explaining reactions to a technology perceived as risky’, Risk Analysis, vol. 10, no. 4.
Chun, A (Cptn) 1993, Human health risk assessment for contaminated sites: workshop, US Environmental Protection Agency, 8-10 November.
Chun, A (Cptn) 1997, Managing community outrage - risk communication for development projects: resource kit, US EPA & MFP Development Corporation, Adelaide, Australia.
Chess, C, Hance, BJ & Sandman, P 1989, Planning dialogue with communities: a risk communication workbook, Centre for Environmental Communication (CEC), Cook College, Rutgers University.
CEC 1994, Communicating with the public: ten questions environmental managers should ask, Centre for Environmental Communication, Cook College, Rutgers University.
City of Altona 1993, ‘Altona’s three community consultative committees’, 4th national environmental expo, 1993 municipal environment achievement awards, City of Altona.
Corvello, VT, McCallum, DB & Pavlova, MT (eds) 1989, Effective risk communication, Plenum Press, New York, pp. 45-49.
enHealth 2006, Responding to environmental health incidents, community involvement handbook, enHealth Council, Melbourne NPHP.
Fischer, GW et al. 1991, ‘What risks are people concerned about?’ Risk Analysis, vol. II, no. 2.
Gardner, GT & Gould, LC 1989, ‘Public perceptions of the risks and benefits of technology’, Risk Analysis, vol. 9, no. 2, pp. 225.
Hadden, G 1991, ‘Institution Barriers to Risk Communications’ Risk Analysis, vol. II, no. 2, pp. 301.
Health Canada 2006, Improving Stakeholder Relationships: Public Involvement and the Federal Contaminated Sites Action Plan: A Guide for Site Managers, Minister of Public Works and Government Services Canada, Ottawa, Ontario.
Heath, L, Pollard, S, Hrudey, S & Smith, G 2010, Engaging the community: a handbook for professionals managing contaminated land, CRC for Contamination Assessment and Remediation of the Environment, Adelaide, Australia.
Harris, JS 1983, ‘Toxic uproar: a community history’, Journal of Public Health Policy, vol. 4, no. 2, pp. 189-190.
International Association for Public Participation (IAP2) (2000) Code of Ethics for Public Participation Practitioners.
International Association for Public Participation (IAP2) Website C, Hodgson, N & Reid, T (eds) 2003, Facilitation tool kit: a practical guide for working more effectively with people and groups, WA Department of Environmental Protection, Water and Rivers Commission and Department of Conservation and Land Management, Western Australia.
Kinke, A & Renn, O 2002, ‘A new approach to risk evaluation and management: risk based, precaution-based, and discourse-based strategies’, Risk Analysis vol. 22, no. 6, pp. 1070-1091.
Lundren, R & McMakin, A 2009, Risk communication: a handbook for communicating environmental, safety, and health risks, 4th edn, John Wiley & Sons, New Jersey.
McKersie, F, O’Brien, G & Royston, D 1992, ‘Siting a secure landfill: the community consultation factors’, Proceedings from 1st national hazardous and soil waste convention.
Meek, T (EPA) 1994, Effective community consultation, paper presented at the odour workshop, Clean Air Society of Australia & New Zealand, in cooperation with the Office of the South Australian Environment Protection Authority & the Institute of Public and Environmental Health Officers, August.
Meek, T 1996, Community right to know: community involvement in decision-making?, paper presented at the 13th International Clean Air Society of Australia & New Zealand conference, September.
Meek, T & Monahan, D (EPA) & Mival, K (Dames & Moore) 1994, Lead contamination on residential properties - assessment, clean-up and community aspects, paper presented at the 2nd National Hazardous & Solid Waste Convention & Trade Exhibition.
NAB & SWMG (2000), A Case Study of Problem Solving Through Effective Community Consultation, National Advisory Body (NAB) on Scheduled Wastes and Scheduled Wastes Management Group (SWMG), Canberra, Australia.
Otway, H & Wynne, B 1989, ‘Risk communication: paradigm and paradox’, Risk Analysis, vol. 9, no. 2, pp. 143.
PCB Consultation Panel 1995, Summary report of the PCB consultation panel on major outcomes from PCB public consultation, April.
Rust PPK Pty Ltd 1995, Community, industry and government partnerships: a review of consultation processes, June.
SA DHUD 1994, Human services planning kit, South Australian Urban Land Trust, Department of Housing and Urban Development, Adelaide, Australia.
SAHC 1991, The health risk assessment and management of contaminated sites, South Australian Health Commission, Adelaide, Australia.
Sandman, PM 1989, ‘Hazard versus outrage in the public perceptions of risk’, in Corvello, VT, DB McCallum, DB & Pavlova, MT (eds), Effective risk communication, Plenum Press, New York, pp. 45–49.
Scottish Environment Protection Agency 2010, Communicating Understanding of Contaminated Land Risks, Project UKLQ13, Scotland and Northern Ireland Forum for Environmental Research (SNIFFER), Edinburgh.
Starr, G, Langley, A & Taylor, A 2000, Environmental Health Risk Perception in Australia: A Research Report to the Commonwealth Department of Health and Aged Care, Adelaide: Centre for Population Studies in Epidemiology, Department of Human Services.
US EPA 1993, Ecological risk assessment for contaminated sites, workshop, 11 November.
US EPA 2007, Risk communication in action: the risk communication workbook, EPA/625/R-05/003, National Research Programs, United States Environmental Protection Agency, Washington, DC, USA.
US EPA 2007, Risk communication in action: the tools of message mapping, EPA/625/R-06/012, National Research Programs, United States Environmental Protection Agency, Washington, DC, USA.
VIC DSE 2005, Effective engagement: building relationships with community and other stakeholders, Book 1, An introduction to engagement, Department of Sustainability and Environment, Victoria, available online at DSE 2005, Effective engagement: building relationships with community and other stakeholders, Book 2, The engagement planning workbook, Department of Sustainability and Environment, Victoria, available online at DSE 2005, Effective engagement: building relationships with community and other stakeholders, Book 3, The engagement toolkit, Department of Sustainability and Environment, Victoria, available online at DEC 2006, Contaminated Sites Management Series: Community Consultation Guideline, Western Australia Department of Environment and Conservation, Perth, WA.
WA DoE 2003, Community involvement, framework, Western Australian Department of Environment, Perth, WA.
8 Glossary
Community engagement is the process of communicating and deliberating with the community and other stakeholders. It can include a variety of project-specific approaches:
Inform one-way communication or delivery of information Consult providing for ongoing public feedback Involve a two-way process to ensure community concerns are considered as part of the decision-making process Collaborate developing partnerships with the community to make recommendations Empower allowing the community to make decisions and to implement and manage change. Community means those individuals and/or groups residing in the locality where a site assessment is to be conducted and who may be affected by the assessment and/or possible site contamination physically (for example, through risks to health or the environment, loss of amenity) or non-physically (for example, via concern about possible contamination). Contamination means the condition of land or water where any chemical substance or waste has been added as a direct result or indirect result of human activity at above background level and represents, or potentially represents, an adverse health or environmental impact. EPA means the relevant environment protection authority or equivalent agency responsible for the regulation and management of contaminated land. Exposure occurs when a chemical, physical or biological agent makes contact with the human body through breathing, skin contact or ingestion; for example, contaminants in soil, water and air. Hazard is the intrinsic capacity of a chemical, biological, physical or social agent to produce a particular type of adverse health or ecological effect. Community engagement consultant means an appropriately skilled professional employed to develop and implement the community engagement and risk communication plan. Remediation means the clean-up or mitigation of pollution or of contamination of soil or water by various methods. Risk assessment means the process of estimating the potential impact of a chemical, physical, microbiological or social hazard on a specified human population or ecosystem under a specific set of conditions within a certain timeframe. Risk communication means an interactive process involving the exchange among individuals, groups and institutions of information and expert opinion about the nature, severity and acceptability of risks and the decisions to be taken to combat them. Risk communication is delivered most efficiently in the context of a well-structured community engagement process. Risk management means the decision-making process to analyse and compare the range of options for site management and select the appropriate response to a potential health or environmental hazard. It may involve considerations of political, social, economic, environmental and engineering factors. Risk means the probability in a certain timeframe that an adverse outcome will occur in a person, group, or ecological system that is exposed to a particular dose or concentration of a hazardous agent; that is, it depends on both the level of toxicity of hazardous agent and the level of exposure. Risk perception is the subjective judgment that people make about the characteristics and severity of a risk. Site managers are those responsible for environmental site assessment, risk assessment and risk management and may include landowners, contaminated land consultants, contractors or environmental auditors. Site means the parcel of land being assessed for contamination. Stakeholder means one who has an interest in a project or who may be affected by it. Sustainable development means development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Wider community means individuals and/or groups, not necessarily residing in the locality of a site assessment, who may have an interest in the assessment.
Page
1 Introduction 1
2 Purpose 2
3 Use of these guidelines 3
4 Professional roles in the assessment of site contamination 4
4.1Auditors and third-party reviewers 4
4.2Environmental consultants 4
5 Application for acceptance 6
6 Assessment Criteria 7
6.1Technical basis of application 7
6.2Legislative and guideline knowledge and understanding 8
6.3National framework 8
6.4Experience and expertise 8
6.5Qualifications 8
6.6Professional societies 9
6.7Professional experience 9
6.8Principles of audits 9
6.9Literature 9
6.10Professional development 10
7 Acceptance processes and general conditions 11
7.1General acceptance processes 11
7.2Ongoing practice 11
1 Introduction
The assessment of contaminated sites is a specialised professional area involving a number of disciplines. Practitioners must have a range of competencies and be able to recognise the need for supporting professional advice beyond their own expertise when assessing contamination and its effects on land use and the environment.
The extent to which these competencies are required varies with the level and nature of work being carried out by the professional. For example, the professional may be operating as an accredited auditor, a third-party reviewer, a specialist professional certifying work under statute or an environmental consultant involved in carrying out contaminated site assessments. The complexity of contamination issues will vary on individual sites from a single known contaminant with limited site distribution to sites with multiple contaminants of unknown vertical and lateral spread, off-site impacts and obvious human health and environmental risks.
Professional assessments of site contamination deal with health and environmental issues of concern to landowners, occupiers, regulators, local government, planning authorities and the public. These assessments are required by regulatory and planning authorities for the management of contaminated land and in development approval processes.
This Schedule should assist the development of arrangements to provide consistency in the recognition of competent professionals for contaminated site assessment across Australia.
2 Purpose
The purpose of this Schedule is to:
· describe the competencies and experience that are essential for professionals involved in contaminated site assessment including auditors, third-party reviewers and professionals who are certifying assessments of complex contaminated sites
· provide a general framework for the appointment or acceptance by regulatory authorities of contaminated land professionals who are required under statute to certify site assessments.
3 Use of these guidelines
This Schedule is primarily intended for use by regulatory authorities within the scope of their environmental and planning legislation. Its application in individual states and territories will assist in establishing a consistent minimum level of knowledge, experience and technical competencies for environmental professionals carrying out contaminated site assessment within Australia, and the mutual recognition of these professionals.
Individual states and territories may have specific legislative requirements relating to the appointment or acceptance of:
· auditors appointed or accredited for the independent third-party auditing of site contamination
· third-party reviewers accepted to conduct independent third-party reviews for the certification of assessment and remediation
· specialised professionals who are required under statute to demonstrate relevant qualifications and experience when presenting contamination assessment reports to regulatory authorities and to certify assessment work under statutory declarations.
To be recognised in these roles individuals must be professionals with significant technical expertise and experience in the assessment of site contamination. The application of a high level of technical competency assessment is to be applied to the appointment of accredited auditors and to third-party reviewers and the acceptance of professionals who are certifying assessments of contaminated sites.
While regulatory authorities in individual states and territories may require specific knowledge and understanding of legislation and guidelines relevant to their jurisdiction, it is intended the broad assessment process and minimum criteria described in this Schedule be used to establish the professional competencies required and to then determine the technical skills, experience and proficiency of these individuals.
Relevant aspects of this Schedule provide advice on appropriate qualifications, experience and competencies of environmental consultants involved in the assessment and/or remediation of contaminated sites. These considerations may also be applied to assess the abilities of environmental professionals and their companies not otherwise subject to specific legislative requirements for appointment or accreditation, in order to assess their capability to carry out specific assessments of site contamination.
To improve the quality of site contamination assessment work and encourage professional specialisation in this area, regulatory authorities may use this Schedule as the basis of advice for stakeholders, including professional associations, on the competence of practitioners.
This Schedule may also assist members of the community in decision-making regarding the employment of environmental professionals for contaminated site assessment work, by informing them of the broad range of competencies, knowledge and experience that should be held by environmental professionals in designing and carrying out contaminated site assessments.
4 Professional roles in the assessment of site contamination
Professionals involved in the assessment of site contamination need to demonstrate appropriate competence, knowledge and experience relative to their role and the complexity of site contamination.
4.1 Auditors and third-party reviewers
Auditors and third-party reviewers appointed under legislative requirements typically only act in the capacity of that role when they are carrying out an audit or a third-party review in accordance with those legislative requirements. In other situations, for example, when that person is involved in any other site assessment and/or remediation, that individual is acting as an environmental consultant.
The role of an auditor or third-party reviewer acting under statute is to carry out reviews of the assessment and/or remediation work carried out by environmental consultants and to provide independent expert opinion regarding any potential impacts to human health and/or the environment relating to site contamination, and the suitability of land for its intended use.
Auditors and third-party reviewers must be able to demonstrate that:
· they have exercised their own professional judgment
· they have taken appropriate specialised advice when the contamination issue is outside their expertise
· their opinions have been reached independently
· in forming those opinions, they have not been unduly influenced by the views or actions of others who may have an interest in the outcome of the review.
Legislative requirements may include provisions in relation to conflicts of interest and ethical codes of conduct and integrity. Individuals may be subject to penalties for any breaches of those requirements.
There is a clear distinction between the roles of an auditor or third-party reviewer acting under statute, and an environmental consultant. Jurisdictions typically have legislation regarding the provision of false and misleading information relating to statutory decisions.
Individuals applying to regulatory authorities for the purpose of appointment or acceptance of certification in these roles need to demonstrate significant knowledge and extensive experience in site contamination assessments. This should include the ability to meet all of the assessment criteria described in Section 6 of this Schedule.
The multidisciplinary nature of site contamination assessment requires that auditors and third-party reviewers are able to identify when there is an issue that is not within their own expertise and to obtain the additional professional advice required. In considering applications, it should be recognised by regulatory authorities that it is unlikely an individual could demonstrate all technical competencies relevant to site contamination.
4.2 Environmental consultants
An environmental consultant is usually a company that employs a range of professional and technical staff, or it can be an individual person. An environmental consultant can be engaged to carry out site contamination assessments for a variety of reasons. Engagement of a consultant is undertaken in accordance with the terms and conditions of that company or, in some cases, to complete an agreed scope of works. Their role is to design, prepare and carry out the assessment and/or remediation work in accordance with the scope of works.
Although not necessarily subject to specific legislative requirements, environmental consultants responsible for the assessment of contaminated sites and the preparation of assessment reports should demonstrate relevant qualifications and experience to a level appropriate to the contamination issues relevant to the site under investigation.
While not having to demonstrate meeting all assessment criteria identified in Section 6.1 of this Schedule for auditors and third-party reviewers under statute, environmental consultants should be able to demonstrate:
· qualifications consistent with this Schedule
· competencies relevant to the work to be undertaken
· demonstrated relevant experience in site assessment
· comprehensive knowledge of relevant legislation and guidelines
· knowledge of relevant scientific literature for assessment of the impacts of site contamination on human health and the environment
· a demonstrated commitment to training and professional development
· relevant memberships and/or accreditation with professional societies.
Further information about qualifications and experience is provided in Section 6 of this Schedule.
Consultants should provide evidence that addresses these factors when it is requested. Individual jurisdictions may accredit consultants for certain activities or provide guidance on selection criteria and should be contacted for further advice as appropriate.
5 Application for acceptance
The application requirements described in this section relate to individuals applying to regulatory authorities for the appointment or acceptance of certification in the role of an environmental auditor or third-party reviewer under statute.
Subject to the specific legislative, policy and guideline frameworks applying in each state and territory, regulatory authorities reviewing applications from professionals for acceptance of their qualifications and experience should require the following information to be supplied for assessment.
1. A detailed current curriculum vitae that identifies relevant qualifications and the number of years’ relevant experience held by the applicant in the assessment of contaminated sites.
2. A detailed statement of the applicant’s knowledge, experience and expertise in relation to the assessment of contaminated sites and environmental issues, addressing the required technical competencies.
3. A statement demonstrating the applicant’s understanding of the relevant provisions of environmental legislation in the particular state or territory and knowledge of policy, regulations and procedures.
4. A statement demonstrating the applicant’s knowledge and understanding of the relevant provisions of guidelines issued or approved in the particular state or territory.
5. Nomination of people or companies who will provide support to the applicant in the competencies in which the applicant is not an expert.
6. Information that demonstrates the applicant’s experience in forming and managing appropriate multidisciplinary teams for complex assessments.
7. A commitment that a professional liability insurance policy is, or will be, held by the applicant or on the applicant’s behalf by the company employing the applicant, that demonstrates an appropriate level of coverage. Policies should cover the person for the activities to be undertaken and should not contain any exclusion that may have the effect of limiting cover for work carried out.
8. Examples of two or more relevant reports or studies on site contamination, which were authored or substantially prepared by the applicant and prepared no more than two years prior to the date of application. The reports should demonstrate the applicant’s expertise in the assessment of contamination and their written communication skills. The report should clearly support the statements made by the applicant under items 2, 3 and 4 above. The role of the applicant in conducting the study (consultancy) and in preparing the report must be clearly indicated. Individual regulatory authorities may have specific requirements relating to requiring consent to be obtained from the client(s) for the reports to be submitted with the application, and may decide to return the reports to the applicant.
9. Summary information about additional reports and studies in which the applicant has made a major contribution may be presented, indicating the title of the project, the date of the report, the role of the applicant and the purpose of the project.
10. Nomination of referees. Referees should include people not directly associated with the applicant or the company employing the applicant, who have direct and recent knowledge of the applicant and can confirm the applicant’s experience and expertise as stated under items 2, 3 and 4.
6 Assessment Criteria
This section details appropriate minimum criteria that should be considered by regulatory authorities in the assessment of individual applicants seeking acceptance for certification of contaminated site assessment work. Individual regulatory authorities may have further specific requirements for the criteria.
The ability of environmental consultants not otherwise subject to legislative requirements to demonstrate these criteria may also be used to assist in the decision-making process regarding the use of environmental consultants to carry out the assessment of site contamination.
6.1 Technical basis of application
The applicant should be able to demonstrate extensive experience and a high level of expertise in the core competencies required in each state and territory. In general, this will comprise such experience and expertise in all or a majority of the following:
· assessment of contaminant exposure pathways
· contaminated site assessment and management
· evaluation and interpretation of chemical and analytical data
· soil sampling design and methodology
· soil gas sampling design and methodology
· groundwater sampling design and methodology
· identification of potential human health and environmental risks
· quality control/quality assurance procedures
· risk communication.
The applicant should have basic proficiency in and be able to demonstrate experience and expertise relating to site contamination in the following areas, or otherwise have access to such expertise, to the level required by individual regulatory authorities:
· air quality (volatile emissions and dust) assessment relating to contamination
· assessment of impacts on groundwater from contaminated sites
· contaminant fate and transport
· environmental chemistry
· environmental sampling
· environmental toxicology
· geology
· human health and ecological risk assessment relating to contamination
· human toxicology
· hydrogeology
· identification of contaminants of concern from past industrial land uses
· work health and safety relating to contamination
· remediation technologies and geo-technology
· soil science
· statutory and environmental planning.
6.2 Legislative and guideline knowledge and understanding
The applicant should be able to demonstrate knowledge and an understanding of relevant legislation, regulations and policies relating to site contamination in each state or territory for which acceptance is sought.
The applicant should be able to demonstrate knowledge and an understanding of relevant guidelines issued or approved in each individual state and territory for which acceptance is sought.
The applicant should also be able to demonstrate consistency with relevant legislation and guidelines, in their carrying out and reporting of contaminated site assessments.
6.3 National framework
The applicant should be able to demonstrate an understanding of the National Environment Protection (Assessment of Site Contamination) Measure 1999 and other national guidance documents relevant to contamination.
The applicant should also be able to demonstrate consistency with the National Environment Protection (Assessment of Site Contamination) Measure 1999, in their carrying out and reporting of contaminated site assessments.
6.4 Experience and expertise
The applicant should demonstrate his/her expertise in the competencies identified in Section 6.1, to the level required by individual states and territories.
Where a competency, other than a core competency, is not able to be demonstrated by the applicant to the level required, the applicant should demonstrate access to relevant expertise in that competency.
All applicants should be required to nominate an expert support team of specialised professionals on whom they would rely for site issues beyond their areas of expertise.
Regulatory authorities in individual states and territories may have specific requirements relating to the qualifications, experience and expertise of expert support team members, and their use by applicants. However, an individual nominated as an expert in an auditor’s support team should:
· be able to demonstrate a high level expertise or knowledge in the competencies where the applicant does not personally possess such expertise or knowledge to the level required
· hold qualifications relevant to and supporting the nominated competencies
· have at least eight years’ relevant experience
· be actively working in the field of the nominated competencies
· be a current member of professional organisations/associations relevant to the field of the nominated competencies
· be able to demonstrate an ongoing commitment to professional training and development.
The applicant should demonstrate a sound ability and experience in forming and managing a multidisciplinary team for complex site assessment which contains the appropriate balance of expertise.
6.5 Qualifications
The applicant should hold qualifications as required by the regulatory authorities in individual states and territories (for example, a relevant bachelor’s degree from a recognised institution).
6.6 Professional societies
The applicant should be required to demonstrate individual membership of and/or accreditation from one or more relevant professional societies, for example, Engineers Australia, the Royal Australian Chemical Institute, the Australian Institute of Geoscientists, the Environment Institute of Australia and New Zealand. In addition, applicants should also be able to demonstrate membership and/or accreditation of professional associations where relevant to nominated technical competencies (identified in section 6.1).
When considering professional societies that may be acceptable, regulatory authorities should consider the following criteria:
· discipline or area of expertise or interest relates directly to the assessment and management of contaminated sites
· membership is qualification-based
· membership requires adherence to an appropriate code of ethics.
Regulatory authorities should also take into consideration whether the maintenance of the membership and/or accreditation by the applicant is active and current. Maintenance of memberships should be in accordance to any code of ethics relevant to the particular society, and adherence to professional standards.
6.7 Professional experience
Regulatory authorities in individual states and territories may have specific requirements for the number of years of experience that applicants would be expected to have. Applicants should be expected to have had at least eight years’ continuous relevant experience in the assessment and management of contaminated sites for appointment as accredited auditors or for acceptance as professionals involved in preparation and certification of assessments of complex contaminated sites. Individual regulatory authorities may also consider applicants with less than the required years’ contaminated land experience but with significant years of relevant and related environmental experience, including assessment and management of major environmental issues involving complex sampling design and chemical or hydrogeological data collection and interpretation, where this experience is relevant.
It is generally desirable that an applicant’s experience include at least two years of relevant work in Australia and two years in the role of project manager involving a multidisciplinary team approach to contaminated land or related environmental assessment and management.
It is preferable that the experience in contaminated sites work is broadly based in terms of the scale of work undertaken, the range of contaminants encountered and the scope of work performed, and includes contaminated site or environmental auditing experience, for example, as a member of an accredited auditor’s expert support team or as an auditor’s assistant.
6.8 Principles of audits
The applicant should be able to demonstrate a thorough understanding of the principles of, and methods for, conducting contaminated site assessments and environmental audits as required by the relevant state and territory, and be able to act independently using balanced professional judgement based on site-specific data and the advice of specialised support professionals.
6.9 Literature
The applicant should be able to demonstrate up-to-date knowledge of relevant scientific, technical developments and regulatory literature relating to new legislation and court proceedings and decisions relating to contaminated sites.
6.10 Professional development
The applicant should be able to demonstrate an active commitment to ongoing training and professional development relevant to the technical competencies (identified in Section 6.1) and the assessment and/or remediation of contaminated sites. Applicants should be able to provide evidence of continuous professional development and learning outcomes.
7 Acceptance processes and general conditions
This section provides general guidance on processes for the acceptance and ongoing review of applicants seeking certification of contaminated site assessment work.
7.1 General acceptance processes
Regulatory authorities may apply the following processes for the assessment, selection and review of auditors or third-party reviewers in accordance with legislative requirements and operational policies applying in each jurisdiction.
The regulatory authority may consider the establishment of a panel to assess applications. Typical panels would have not less than three professionals including a suitably qualified chairperson. Panels need to be able to adequately assess all of the competencies relevant to contaminated land assessment and management. The panel must consider the applicant’s ability to meet all of the assessment criteria identified in Section 6, including the composition and relevance of their expert support team, their demonstrated ability to act independently on the basis of factual evidence, and their adherence to ethical and professional standards of conduct.
7.2 Ongoing practice
Once appointed or accepted for certification, regulatory authorities should ensure that professionals continue to update their training and experience in relation to the assessment of contamination, and comply with the relevant legislative requirements of the individual states and territories. This may be carried out through the implementation of a quality assurance program by the regulatory authority and review of a person’s appointment, particularly at times of renewal. Applicants for renewal should also be able to demonstrate they are actively auditing.
The regulatory authority in individual states and territories may conduct independent audits and peer reviews of assessment work and adopt a system that involves the periodic review of the status of appointed professionals. Reviewers within the regulatory authorities should have appropriate qualifications and experience.
In the event of proven malpractice, such as a breach of legislative requirements by accepted persons, the regulatory authority may suspend or revoke the acceptance and may apply appropriate additional penalties in accordance with their legislative requirements.
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