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Environment Protection Authority

2013 Amendment of the Assessment of Site Contamination NEPM 1999

On 11 April 2013, the Standing Council on Environment and Water (SCEW) agreed to amend the National Environment Protection (Assessment of Site Contamination) Measure 1999 (the ‘NEPM’). The amendment came into effect on 16 May 2013.

The amended NEPM and a supporting Toolbox are available via the National Environment Protection Council (NEPC) website.

On 29 July 2013, an errata was published on the NEPC website to address minor errors in the published NEPM amendment and was last updated on 30 April 2014.

On 30 April 2014, a series of frequently asked questions was published on the NEPC website.

Legislative changes in NSW

To enable its implementation in NSW, the list of approved guidelines under section 105 of the Contaminated Land Management Act 1997 has been updated to include the amended NEPM and its associated schedules.

Transitional arrangements

Regulatory authorities in all Australian states and territories have agreed, in principle, to a transition period of up to 12 months for full implementation of the amended NEPM. The transition period allows for regulators to implement any legislative or administrative steps required to put the amendment into effect, including the update of relevant guidelines.

In NSW, the amended NEPM and its supporting schedules apply to works completed after 15 May 2013.

Any exemptions from applying the amended NEPM must be appropriately justified and only when all of the following circumstances are met:

  • reports are almost complete by 15 May 2013, and
  • significant additional works and/or cost would be necessary to meet the amended NEPM, and
  • there are no unacceptable risks associated with applying the original NEPM.

Application of the original NEPM must include appropriate justification and early communication between relevant stakeholders (client, consultant, auditor, the EPA, local council, etc.).

Frequently asked questions about the amended NEPM


1. Can I still use the original version of the NEPM during the transitional period?

Any deviation from guidelines made or approved by the EPA under s.105 of the Contaminated Land Management Act 1997 (CLM Act) will have to be appropriately justified, including use or reference to the original version of the NEPM.

2. What wording should be used to justify the use of the original NEPM?

The EPA cannot comment on the acceptable wording for applying the original version of the NEPM (as published in 1999).

However, it is recommended that a clear statement of justification be included to explain why there are no unacceptable risks associated with applying the original NEPM rather than the amended NEPM that was published in 2013. For example, include a discussion on any differences in relevant investigation levels and justify why those in the original NEPM are appropriate to use on the site.

3. Did the EPA notify councils regarding the NEPM amendment and will the EPA be conducting training for councils?

The EPA has not directly notified councils, although details of the CRC CARE workshops that were offered immediately after the approval of the amended NEPM were included in Local Government NSW’s weekly circular.

Information on the NEPM amendment will also be included in future council workshops coordinated by the EPA.


4. Are the Health Investigation Levels (HILs) in the NEPM (Schedule B1, Table 1A(1)) for 2,4,5-T and 2,4-D correct?

Yes. The HILs for 2,4,5-T and 2,4-D are derived in Schedule B7, Appendix A4 and are best seen in the summary calculation table in Appendix C.

The units have always been reported as mg/kg for both of these substances. The full details of the toxicological review are available in Schedule B7, Appendix A4.

5. Do the Health Screening Levels (HSLs) in the NEPM trigger the Duty to Report, given it is now endorsed under s.105 of the CLM Act?

Yes. The HSLs in the NEPM trigger the duty to notify the EPA of site contamination under section 60 of the CLM Act if levels of the selected petroleum hydrocarbons meet or exceed the HSLs along, with the other criteria required under s.60(3).

6. Are the Ecological Investigation Levels (EILs) and Ecological Screening Levels (ESLs) still ‘single point’ criteria, or is there scope for statistical evaluation?

Although not explicitly stated, the information provided in Schedule B1 intends to allow for statistics to be applied to both human health and ecological criteria. It is critical to note that the statistics are calculated for a relevant ‘area’ based on the conceptual site model, taking into account the receptors present.

Further guidance is also provided in Section 3.4.2 of Schedule B1 about ecological assessment.

7.  What are the correct ESL values for benzo[a]pyrene (BaP)?

The correct ESL is 1.4 mg/kg for BaP in both coarse and fine soil.

There was an error in the review paper, which has been corrected and is available in the errata list in the NEPM home page on the NEPC website.

8. Where NEPM does not provide a generic EIL, can the phytoxicity-based investigation levels (PBILs) in the Guidelines for the NSW site auditor scheme (2nd edition) be used?

No. While the NEPM only provides EILs for a limited number of analytes, it also provides the methodology to develop EILs for other analytes, such as those for which PBILs have been included in the Site Auditor Guidelines.

9. Should an ambient background concentration (ABC) be included for fill materials?

A distinction should be made between uncontaminated natural materials from a known local source such as clay and sand used for levelling or landscaping purposes (‘clean fill’) and heterogeneous fill of unknown origin. While it may be argued that an ABC could be calculated (via sampling and analysis) for clean fill of known origin and date of emplacement, it is not appropriate to calculate/derive an ABC for other types of fill.

10. Are the ESLs for xylene in Table 1B(6) of Schedule B1 correct?

Yes. The author’s explanatory papers are available in the NEPM toolbox on the NEPC website for further information.

11. The Groundwater Investigation Levels (GILs) in the NEPM refer to the Guidelines for managing risks in recreational waters 2008. Will these guidelines be approved under s.105 of the CLM Act?

There is currently no intention to approve these guidelines separately under s.105 of the CLM Act. However, it is expected that auditors and consultants will use the most recent version of guidelines in their contaminated sites work.

12. The 2013 version of the NEPM appears to present no specific investigation level for toluene in groundwater. Does the criterion for toluene of 300 ug/L in the Guidelines for assessing service station sites (EPA 1994) still apply?

The NEPM does not present a GIL for toluene for fresh and marine waters, but it does include a GIL for drinking water. The NEPM notes that additional GILs applicable to other uses (i.e. industrial, agricultural and recreational) are provided in other documents as referenced in Table 5 of Schedule B1. The NEPM does not present a groundwater HSL for vapour intrusion because it is not limiting.

The Australian water quality guidelines 2000 include low reliability trigger values for toluene. These guidelines are approved by the EPA under s.105 of the CLM Act. Consideration may be given as to whether they are appropriate for application to a site (e.g. is 95% protection level appropriate?).

13. Can the EPA provide some advice on the practical implementation of the management limits for petroleum hydrocarbons?

The management limits for petroleum hydrocarbons are applied after consideration of relevant ESLs and HSLs. The EPA is considering adding them to the decision-making process for assessing urban redevelopment sites in the review of the Guidelines for the NSW site auditor scheme (2nd edition).

14. The Guidelines for the NSW site auditor scheme (2nd edition) say that consideration must be given to the most sensitive use on a mixed-use site. The NEPM provides a more pragmatic approach consistent with land use changes within a site. Will the approach in the NEPM be included in the revision of the site auditor guidelines?

Yes. The revision of the site auditor guidelines will adopt the approach suggested in the NEPM.

15. Should the EPA be notified of asbestos under s.60 of the CLM Act?

In general, the presence of asbestos does not warrant that a site is notified to the NSW EPA under the CLM Act. Sites may be regulated under the CLM Act where the EPA determines that there is ‘significant contamination’ of land, such as where the scale and nature of the contamination is giving rise to actual or potential harm to human health or the environment. This could occur where there are elevated levels of asbestos fibres in air and the responsible party is not addressing the source of the risk.

16. Is organic carbon data required to determine the added contaminant limit (ACL) for copper?

No, only pH and cation exchange capacity (CEC) are required. Refer to Appendix F in Schedule B5c for a more detailed explanation.

17. How do I use the EIL spreadsheets in the NEPM Toolbox on the SCEW website? Is there a database for background levels in the Sydney basin to compare calculated EILs?

Any problems or questions regarding the EIL spreadsheets should be directed to the NEPM homepage available on the NEPC website.

There is not a database available of calculated EILs, but individuals may use available data as long as it is relevant and appropriate references can be found.

18. Why does the EIL spreadsheet in the Toolbox present the added contaminant limits (ACLs) for fresh and aged lead as ‘generic EILs’ without the option to estimate the ambient background concentration (ABC)?

This is a flaw in the spreadsheet. The lead EIL can be calculated as per the procedure in Schedule B1, Section 2.5.10 (EIL = ABC + ACL) or refer to Schedule B5c which contains several example calculations for lead.

Note that there is an error in Schedule B5c, Section – the worked Example 1 (SQG based on LOEC and EC30), the ABC for lead is shown as 150 mg/kg for an old suburb with low traffic volume in South Australia. This should read 30 mg/kg and is displayed correctly as such in Table 67 on page 76.

19. Should there be a table of information on polychlorinated biphenyls (PCBs) in Schedule B7-A5 (Part 1.4.3)?

Yes. The missing table of recommendations for PCBs was inadvertently omitted from the final version of the NEPM but has been included in the errata list that is now available on the NEPC website.

20. Which health screening level (HSL) land-use category should be applied to assess potential vapour intrusion for multi-storey buildings with residential uses at ground level and a basement car park?

The NSW EPA considers it is appropriate to apply HSL land-use category D (commercial/industrial) to assess potential vapour intrusion for multi-storey buildings with residential uses at ground level and where a car park exists in a basement, subject to the HSL application restrictions detailed in the NEPM and in Technical Report No. 10 - Health screening levels for petroleum hydrocarbons in soil and groundwater published by the CRC for Contamination Assessment and Remediation of the Environment (E Friebel and P. Nadebaum, 2011).


21. The SCEW website refers to both the original NEPM and the NEPM (Assessment of Site Contaminaton) Amendment Measure 2013. How should I reference the new version of the NEPM?

The NEPM (Assessment of Site Contamination) Amendment Measure 2013 was repealed on 15 May 2013. The NEPC website was updated on 17 June 2013 and provides access to the amended NEPM.

An appropriate reference to the amended NEPM would be:

National Environment Protection (Assessment of Site Contamination) Measure 1999 (April 2013), NEPC 2013, Canberra.

22. How should I distinguish between the original and amended versions of the NEPM in a report, as works have been completed both pre- and post-amendments?

An example of how to distinguish between the original and amended NEPM in a report could be to reference the amended measure as ‘National Environment Protection (Assessment of Site Contamination) Measure 1999 (April 2013)’ and the original as ‘National Environment Protection (Assessment of Site Contamination) Measure 1999 (1999)’.

Complete references, including publishing details, should be available in a ‘Works cited’ or ‘References’ section within the report.

Further information

Please direct any questions about the amendment of the NEPM to the EPA’s Environment Line on 131 555 or

Page last updated: 09 December 2014