Contaminated land – NSW EPA releases draft guidelines

Proposed new contaminated land reporting guidance released by the NSW Environment Protection Authority (EPA) on 27 August 2019 will provide best practice standards for consultants preparing site reports and make it clear what information needs to be reported to the EPA, and also when consultants should tell their clients about any potential duty to report contamination.

Draft contaminated land reporting guidelines – key changes

The draft Guidelines for Consultants reporting on Contaminated Land aim to ensure contaminated land consultants prepare reports in the correct format and with the right information to promote efficient review by site auditors, regulators and other relevant parties. The contaminated land guidelines will replace the current 2011 version which has not undergone major change since its initial publication in 1997. The EPA intends the guidelines to support the national framework and strengthen contaminated land management by incorporating industry best practice.

Under the draft guidelines, the former "Investigation Stages" have been re-named "Reporting Stages" and expanded to include additional stages such as preparing sampling and analysis quality plans, and conducting site specific risk assessments and modelling. The reporting checklists attached to the current guidelines have also been given a significant overhaul and are now more comprehensive, addressing report expectations for each of the Reporting Stages individually. These are to be read in conjunction with separate approved guidelines published by the EPA on each of the Reporting Stages – for example, the Guidelines for the NSW Site Auditor Scheme (3rd edition, October 2017) and the Contaminated Land Certification Policy (November 2017).

In regards to the specific Reporting Stages:

Conceptual site models are now required to provide the framework to identify sources of contamination, contaminant migration pathways, receptors and exposure mechanisms;

• Sampling and analysis quality plans are now an individual requirement, separate from the preliminary site investigation, with specific criteria such as ensuring field investigations are conducted in a manner which enables the collection and reporting of reliable data;
• Consultants are now expected to take reasonable steps to draw their client's attention to any potential duty to report contamination requirements to the EPA following the completion of a preliminary site investigation or a detailed site investigation. This expectation is not included in the current guidelines;
• There is a detailed section addressing how and when site-specific risk assessments and modelling should be conducted, particularly in reference to the National Environment Protection (Assessment of Site Contamination) Measure (ASC NEPM) Schedule B2 Guideline on Site Characterisation. The current guidelines do not discuss modelling. Additionally, where consultants do undertake modelling, the draft guidelines stipulate that they should clearly describe any assumptions and uncertainties. Models should also be validated against the results of existing samples (or new sampling results) to verify accurate representation of site conditions.

The reporting requirements for remedial action plans (RAPs) have been significantly expanded. RAPs must now:

• summarise the findings of preliminary and detailed site investigations and risk assessment(s) (where applicable) as well as present the refined conceptual site model;
• define the extent of remediation across the site;
• assess options to achieve remediation goals and select and justify a preferred approach;
• identify how successful implementation of the RAP will be demonstrated (for example, validation requirements through the documentation of site works, sampling and analysis); and
• where the use of remediation technologies or processes is required for major remediation projects, additional technical detail is required to be presented in the form of a Technology Assessment - a stand-alone document prepared in addition to the RAP and containing all relevant information supporting the chosen remediation approach such as proof of concept details and treatability tests;

Ongoing monitoring reporting has also been amended from the current guidelines and must now include:

• a comparison with previous monitoring rounds and statistical or trend analysis;
• justification of any departures from the required monitoring plan;
• a comparison to site-specific criteria which might trigger the need for additional remediation of EPA notification; and
• any contingency actions already undertaken or that are a required response to monitoring results, and by whom.

These compulsory requirements are in addition to those included in the current guidelines, such as descriptions of monitoring parameters and results discussion.

Reflecting an increasing focus on waste management by regulators, under the draft guidelines, the EPA requires RAPs to clearly outline waste classification, handling and tracking requirements in accordance with the Site Auditor Guidelines and the EPA's Waste Classification Guidelines (2014). Further, consultants are expected to prepare RAPs to ensure any remediation is consistent with relevant laws, policies (including planning instruments) and guidelines. These need to be referenced in the RAP.

Greater attention is also given to long-term site management and monitoring, compared to the brief overview of validation and monitoring reporting in the current guidelines. The draft stipulates that, where full clean-up of a site is not feasible or on-site containment of contamination is proposed, an environmental management plan (EMP) is required. EMPs must address the combination of environmental mitigation and monitoring processes for soil, groundwater and hazardous ground gases where relevant. The EPA requires EMPs to include the objectives of the plan as well as details about the nature and location of site contamination, and the long-term management required to ensure the ongoing protection of human health and the environment (both on- and off-site). Such management can include either passive (minimal maintenance and no mechanical components) or active (mechanical components and regular maintenance/inspection) management systems.

Overall, the draft guidelines reflect a greater integration and reference to existing supporting policies and reporting requirements (such as the ASC NEPM schedules and NSW EPA publications) to create a more useful working document than the previous guidelines. The amendments also represent an increased expectation and burden on consultants to adhere to the new criteria and ensure clients are aware of their reporting responsibilities.

Draft hazardous ground gas assessment guidelines

The EPA has also released a separate updated draft guidance addressing assessment and management practices for hazardous ground gases. These gases are frequently identified at industrial sites and old landfills undergoing remediation prior to re-development. They can also impact land adjacent to such sites.

The draft guidelines for the Assessment and Management of Hazardous Ground Gases will replace the current 2012 guidelines. They provide detailed overviews of matters to be considered when assessing and managing ground gases rather than mandatory reporting requirements.

Unlike contaminated land reporting guidelines, there are no major structural changes or updates to the ground gas assessment guidelines. Instead, the draft guidelines account for a 2013 revision of the ASC NEPM and a 2013 British Standard on investigating ground gas. They also consider a 2015 code of practice on designing protective measures for carbon dioxide and methane ground gases in new buildings (see verification and construction quality assurance). Overall, the updates ensure the draft guidelines reflect industry best practice and new developments in the management of ground gases.

One new inclusion is geotechnical considerations, particularly where gas protection measures are proposed for former landfill or filled sites and long-term system stability is a factor. This is an increasingly significant issue given the trend in NSW towards low-density residential development on historically filled land with known ground gas issues. The draft guidelines list multiple matters that may need to be addressed in regards to geotechnical aspects of potentially developments, including geotechnical investigation requirements to determine site ground characteristics, compaction trials, and the impacts of organic content in fill materials on compaction.

Next steps for finalising the draft guidelines

The EPA intends to gazette the final versions of both guidelines by the end of the year. Following this, the EPA, site auditors and contaminated land consultants will be required to adhere to the guidelines.

Consultation for both draft guidelines closes on 8 October 2019.

Submissions on the draft contaminated land guidelines can be made here.

Submissions on the draft ground gases guidelines can be made here.

For more information on the impacts of these draft guidelines or the management of contaminated land generally, please contact Claire Smith.