The study generated three free-to-access reports that offer guidance to site managers and state and federal regulators on how to manage sites contaminated with hydrocarbons known as light non-aqueous phase liquids (LNAPLs), which can pollute soil and groundwater.
The three-year research project, which compared six contaminated sites across Australia, was supported by international experts from environmental consultancies Jacobs and GHD. The study’s findings have the potential to enable earlier decommissioning of petroleum storage facilities and handover of sites, as well as to avoid greenhouse gas emissions from unnecessary LNAPL recovery systems.
The collaborative project was led by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) and supported by Australia’s independent Industry Growth Centre for the Energy Resources Sector — NERA, with key project support from CSIRO through the collection and interpretation of data from individual sites to allow reporting of key findings.
The study found that the rate of hydrocarbon removal by natural degradation (known as natural source zone depletion) will typically exceed that being achieved by active recovery within three to five years of the initial spill. It demonstrated that mass losses from natural degradation were found to be very significant — 1.5 to 50 times greater than is being achieved by physically pumping hydrocarbons from recovery wells.
To ensure the study’s key recommendations benefit Australia’s energy sector, CRC CARE and NERA will launch a new online training program to help accelerate take-up of the findings by site managers and state and federal regulators. The program includes Q&A webinars and self-paced learning packages that share the results, detail new monitoring techniques, and apply key findings to achieve optimal environmental outcomes. Environmental professionals are encouraged to register for the training package (participants can begin the course at any time) or view the course preview video.
NERA CEO Miranda Taylor said the publication of the study was a major achievement for Australia’s energy resources research community and would deliver benefit across the sector.
“Through robust scientific research and international collaboration, this project will directly unlock new industry best practice to help our sector deliver improved environmental outcomes for the communities in which it operates and deliver cost benefits back to industry and taxpayers through more efficient site management protocols,” Ms Taylor said.
CRC CARE Managing Director Professor Ravi Naidu said that the amount of liquid hydrocarbon that is recovered through active remediation diminishes rapidly over time.
“Currently, ongoing hydrocarbon recovery operations are continuing for decades with ever-diminishing recovery rates, incurring huge costs with no environmental benefit,” he said.
The study’s full details and guidance for practitioners are presented in a series of free-to-access reports published by CRC CARE and made available to Australia’s energy resources sector:
CRC CARE and NERA acknowledge Jacobs (Technical Report 44), GHD (CRC CARE Technical Report 46) and CSIRO (CRC CARE Technical Report 47) for their work in developing the reports.
This work has been supported by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), whose activity in this case was funded by National Energy Resources Australia (NERA), which is one of the Australian Government’s Industry Growth Centres. This work was also funded by following industry participants of the Petroleum LNAPL Forum: BP, BHP, Caltex, Viva Energy, ExxonMobil, Chevron, Santos, Quadrant Energy, Rio Tinto.