Dealing with contaminated sites in Australia

By some estimates, Australia has as many as 160,000 potentially contaminated sites. Most of these are located in urban environments, with common examples including disused petrol stations and former industrial sites. Such sites are a major drain on cities and communities. In the worst cases, exposure to harmful chemicals causes illness or even death. Even when contamination is known about and contained, its presence can prevent the development of otherwise productive real estate.

Furthermore, because contaminants are not static, areas previously thought safe can become toxic over time. Take, for example, the current situation in the Adelaide suburb of Clovelly Park, where trichloroethylene (TCE) from former car and car-part factories has been detected in groundwater, soil and, more recently, at elevated levels in indoor air. Amid criticism that residents have not received timely information, the state government is in the process of evacuating dozens of households. The whole process of relocation along with containment or remediation will cost many millions of dollars (not including the legal costs associated with determining who - former site owners or the government - needs to foot the bill).

The need to deal with contaminated sites quickly and cost effectively is one of the major reasons that the federal government - along with state regulators and numerous industry partners - backed the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) in 2005 and extended that support for nine years in 2011. By leading research at several universities and the CSIRO, the CRC is developing remediation technologies designed to solve the contamination problems that most vex industry and government.

One of the best examples is CRC CARE’s collaboration with the Department of Defence to clean up toxic aqueous film-forming foams (AFFFs) such as PFOS and PFOA - active ingredients in firefighting foam - at several Royal Australian Air Force bases around Australia, where levels as high as 30,000 parts per billion (ppb) had been detected. CRC’s scientists, aware of the ability of clay-based materials to immobilise toxins, identified a clay type that is especially effective in trapping the AFFFs. By tailoring its mineral constituents, the researchers were able to fine-tune the clay’s properties to achieve full recovery of the AFFFs. In further laboratory trials, this modified clay, named matCARE, remediated both water and soil, reducing the concentration of PFOS, PFOA and other fluorinated surfactants to below 2 ppb - the level above which site owners must inform authorities. CRC CARE then designed the AFFF remediation technology as a portable, containerised treatment plant, commissioned them at the RAAF bases and trained local personnel to operate and monitor the facilities.

CRC CARE does a great deal of work on contaminated-site policy. The CRC made significant inputs to the 2013 update of the National Environment Protection (Assessment of Site Contamination) Measure, or ASC NEPM, which ensures a nationally consistent approach to the assessment of site contamination. While the ASC NEPM has helped improve the way that contamination is assessed, approaches to remediation itself remain fragmented nationally, with each state setting its own policies and guidelines. CRC CARE is currently leading the effort to harmonise remediation of contaminated sites nationally, through the development of a National Remediation Framework (NRF). Designed to complement the ASC NEPM, the NRF will provide practical guidance to practitioners and regulators with the aim of supporting: ready transfer of best practice among jurisdictions; use of national expertise across jurisdictions (thereby improving overall standards over time); cost efficiencies; a common remediation language across jurisdictions; training efficiencies; and improved confidence and certainty. Over the coming year, CRC CARE will be seeking industry and community feedback on draft NRM documents (see www.crccare.com/knowledge-sharing/national-remediation-framework for more information).

CRC CARE also focuses on green, sustainable remediation technologies. Examples currently under research and development include:

• a two-step underground anaerobic bioreactor - patented as pooCARE - for treating piggery waste;
• bioremediation (using microbes) and phytoremediation (using plants) of petroleum hydrocarbons;
• nanoremediation, including permeable reactive barriers, for soil and groundwater clean-up;
• lidar (laser radar) technology used for real-time tracking of potentially toxic dust plumes emanating from, for example, mining sites.

By training thousands of industry practitioners and supporting dozens of postgraduate research students, the CRC is also working towards more professional industry standards and helping to establish Australia as a world leader in the science of contamination assessment and remediation.