Who are these guidelines for?

These guidelines mainly apply to consultants assessing and managing land contaminated by ground gases in NSW. This may inform their judgement and advice given to their clients. They will be made by the NSW EPA under section 105 of the Contaminated Land Management Act 1997 and take effect on the day that they are published in the NSW Government Gazette. See “What is a statutory guideline?” below for more information.
When published, these guidelines must be considered by:
  • the EPA
  • accredited site auditors when conducting a site audit
  • contaminated land consultants when assessing and managing land contaminated by ground gases
  • those responsible for land contamination with a duty to notify the EPA.

What is the purpose of these guidelines?

The guidelines focus on bulk ground gases (ground gases that occur at percentage concentrations), particularly methane. This is because these are not dealt with in other guidelines in NSW (including the National Environment Protection (Assessment of Site Contamination) Measure 1999), and because they are commonly encountered at potentially hazardous concentrations in a wide range of land uses and geological settings. However, the guidelines also address trace ground gases, providing cross-references to other guidelines where appropriate.
These guidelines are not intended to address on-site issues associated with active landfills that are currently managed through the landfill licensing process; i.e. under an Environment Protection Licence (EPL) issued in line with the Protection of the Environment Operations Act 1997 (POEO Act). However, they will be useful when considering off-site issues associated with such landfills and during landfill closure and post-closure stabilisation.
The guidelines are not intended to be a comprehensive manual of field investigation procedures or mitigation design. References to appropriate sources for such information are provided.
Section 2 of these guidelines describes the issues relating to ground gases as they have been encountered in Australia and overseas. 
Section 3 sets out recommended approaches and procedures for assessing and characterising sites that may be impacted by ground gases.
Section 4 focuses on assessing the risks associated with ground gases, while Section 5 – which is closely linked to Section 4 – outlines options for managing and mitigating those risks.
Section 6 describes the planning and regulatory process relating to ground gases in NSW.

What is a statutory guideline?

The EPA can make or approve guidelines under section 105 of the Contaminated Land Management Act 1997 for the purposes connected with the objects of the Act. These are called statutory guidelines and it is a legal requirement that they must be followed by certain people. These people include:
  • the EPA (when regulating contaminated land)
  • accredited site auditors (when conducting a site audit)
  • contaminated land consultants (when investigating, remediating, validating and reporting on contaminated sites)
  • those responsible for land contamination with a duty to notify the EPA.

When will these guidelines implemented?

These guidelines are anticipated to be published in the NSW Government Gazette by the end of 2019, following the consultation process.
Consultation will close at midnight on 8 October 2019.

Why are these guidelines being updated?

The NSW first published the Guidelines for the Assessment and Management of Sites Impacted by Hazardous Ground Gases (815KB) in November 2012. Since 2012, there have been significant updates and changes to other relevant guidance, most notably the National Environment Protection (Assessment of Site Contamination) Measure 1999, which was revised in May 2013 
  • British Standard (BS) 8576:2013, Guidance on Investigations for Ground Gas – Permanent Gases and Volatile Organic Compounds (VOCs), which was first published in 2013 
  • BS 8485:2015, Code of Practice for the Design of Protective Measures for Methane and Carbon Dioxide Ground Gases for New Buildings, revised in 2015.
A revised edition of these guidelines is timely.

How can I have my say?

Consultation is closed

Consultation was open for six weeks, from 27 August until midnight 8 October 2019.