Acid mine drainage in Australia: its extent and potential future liability. Supervising Scientist Report 125

In order to better understand the impact of acid drainage in Australia and to provide a basis for assessing long-term management options, the Office of the Supervising Scientist (OSS) and the Australian Centre for Minesite Rehabilitation Research (ACMRR) initiated this study to prepare a status report on acid mine drainage in Australia. The study is supported by the Minerals Council of Australia. The coverage of this study includes all mine sites where sulphidic oxidation in mine wastes or mine workings leads to the release of contaminated drainage with off-site impacts. The objectives of the study were: 1. to quantify and characterise the generation of contaminated drainage by sulphidic oxidation from historic and current mining activities in Australia; 2. to develop a classification scheme to characterise the potential for off-site impacts from sulphidic oxidation in mine wastes; 3. to compare the cost at the national level of managing sulphidic oxidation in mine wastes and any resulting contaminated drainage with other mining and environmental costs; 4. to make recommendations based on the information received to improve the understanding and management of acid mine drainage in Australia. Information was collected on the extent and management of sulphidic oxidation and acid drainage at operating, historic and derelict mines in Australia. Mining operators, environmental officers, industry representatives, state government departments and others were asked about their experience with acid mine drainage and how it is currently managed at operating and historic mine sites. Based on the information collected, the additional cost of managing potentially acid generating wastes at operating mine sites is estimated to be about AUD 60 million per year. Potentially, the financial risk could be much greater if sulphide oxidation and release of pollutants is discovered after mine closure, as was the case for historic sites like Mt Lyell, Rum Jungle or Mt Morgan. The recommendations cover four main issues: rehabilitation technologies, mine planning, waste characterisation and technical awareness of acid drainage issues