New remediation guidelines for petroleum contamination

The Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) has released industry advice claimed to place Australia at the cutting edge in the clean-up of petroleum-based contaminants in groundwater. CRC CARE Managing Director Professor Ravi Naidu says the guide is the result of a worldwide search for the latest in clean-up science and technology by the CRC’s scientists, as well as research carried out under Australian conditions.

The report details the best ways to assess, remediate and manage petroleum contamination in soil and groundwater - a problem in over two-thirds of contaminated sites in Australia. It specifically addresses the difficult issue of petroleum light non-aqueous phase liquids (LNAPLs) - substances which float on top of water and can migrate long distances, contaminating water supplies and emitting toxic vapours into homes and workplaces.

“Subsurface contamination by petroleum hydrocarbons is one of the most common forms of pollution in modern society,” Professor Naidu said. “It is caused by fuel, oil and gas leaks and spills, and commonly occurs around industrial sites where these products have long been used or stored.

“Once this oily residue escapes into groundwater, it critical for human health and environmental safety that it is cleaned up effectively, using the best possible techniques.”

Professor Naidu said Australia has been lacking a single common approach to this issue. The first-of-its-kind report will therefore “form a platform for a consistent, trans-jurisdictional approach to the management of LNAPL impacts across Australia, and [will be] a focal document for a series of CRC CARE technical reports which address the management of LNAPL and subsurface petroleum hydrocarbons”, he stated.

The report emphasises that each hydrocarbon pollution scenario is unique, due to variations in the source pollutants, soil and groundwater conditions. Solving the problem requires the methodical application of a systematic approach, which involves:

• engaging with regulators and other stakeholders at an early stage to identify and agree on remediation goals and end points
• prioritising sites, particularly where an emergency response to a pollution incident and associated statutory reporting is concerned
• defining site sensitivity
• fully understanding the problem
• setting clear remediation goals and end points
• selecting the best available, affordable clean-up technology
• pilot testing the chosen technology
• designing, installing and commissioning the system safely
• monitoring remediation performance
• developing a sound plan to close out the clean-up, acceptable to all involved.

The report ‘LNAPL remediation guidance: a practitioners’ guide for the analysis, management and remediation of LNAPL’ is available at http://www.crccare.com/publications/technical-reports.