New Ground Gas Assessment Guidelines

February 18th, 2020

The NSW EPA published the ‘Assessment and Management of Hazardous Ground Gas: Contaminated Land Guidelines’ in late 2019.    The new guidelines replace the ‘Guidelines for the Assessment and Management of Sites Impacted by Hazardous Ground Gases’ (NSW EPA, 2012).

This second edition of the guidelines is timely as practitioners in NSW have gained substantial experience working with the 2012 guidelines.  There have been significant changes to other relevant guidance documents since 2012, including:

  • National Environment Protection (Assessment of Site Contamination) Measure 1999 (the ASC NEPM), 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+A1:2019, Code of Practice for the Design of Protective Measures for Methane and Carbon Dioxide Ground Gases for New Buildings, fully revised in 2015, further amended in 2019; and
  • CIRIA C748, Guidance on the Use of Plastic Membranes as VOC Vapour Barriers, first published in 2014.

The guidelines have been updated to ensure consistency with these documents.    

Land uses associated with the generation of hazardous ground gases include:

  • Man-made:  waste landfills, uncontrolled fill, reclaimed wetlands and mangroves, agricultural wastes, sewers, burial grounds, chemical and other industrial sites, petroleum fuel sites, dry cleaning, electronics, foundry sands, natural gas pipes, mining.
  • Natural:  soil, swamps, wetlands, waterlogged soils, coal measures, organic and carbonate strata, natural gas traps and granite.

Hazardous ground gases may be an issue when redeveloping potentially contaminated land or development adjacent to such land.

Do you require a contamination assessment as part of a development approval?  Are you looking for an innovative approach to contamination assessment and management? The qualified and experienced professionals at Metech Consulting focus on site-specific, cost-effective solutions to solve contamination challenges and provide our clients with the advice they need.  Contact us with your enquiry here.