Case study 1: Thala Valley Waste Removal Project
Removing waste is a critical part of maintaining the integrity of the Antarctic environment.
During the 2010–11 season the Australian Antarctic Division (AAD) completed a long-term clean-up program, removing contaminated waste from a disused tip site near Casey Station. This program began over 15 years ago, with an initial assessment of the site and consideration of the most effective remediation technologies.
Remediation then began in November 2003, and soon after the AAD removed 1 000 square metres of the contaminated waste, burying it in a secure site in Tasmania.
At the same time, AAD set up a monitoring program to evaluate the remediation program’s effectiveness. This involved a series of ecological field experiments to provide information at different times, and focused on detecting the impacts of the contamination in the marine benthic environment (the sea bottom) in Brown Bay. Using excavators and bulldozers, waste and contaminated soil was extracted from frozen ground and placed it into leak-proof containers for further assessment.
The final 1 000 tonnes of waste was removed in 168 purpose-built waste containers. The Chinese Antarctic vessel Xue Long assisted to get the waste back to Australia.
Burial of the waste was completed in Western Australia in April 2011.
The project has now moved to the final site validation stage. Chemical and biological monitoring over the coming years will continue to determine to what degree the clean-up has restored the natural biological and environmental conditions and over what time scale.
While the success of the remediation is yet to be fully evaluated, from both operational and ecological perspectives, it demonstrates Australia’s current approach to waste management in Antarctica—that the environmental risks posed by contaminated sites is unacceptable, and resolving the present environmental issues resulting from past practices is important.
To successfully complete this project new techniques to remediate the contaminated soils and monitor the environmental impact needed to be developed. It is an example of how to go about remediation activity—assessing whether removal of waste will have a greater environmental impact than leaving it in-situ. It also shows the most effective methods to assess the short, medium and long-term environmental effects of a clean-up operation.
Experiences and the lessons learned have been communicated through international forums, as well as publications in peer-reviewed scientific journals. The robust methodology that Australia has developed through careful planning and experience could be used in the remediation of other similar sites in Antarctica.
The program was undertaken to meet Australia’s obligations under Annex III to the Protocol on Environmental Protection to the Antarctic Treaty, which requires the clean-up of past and present waste disposal sites.