Pitfalls of gold mine sites in care and maintenance

摘要

Gold is a highly valued and volatile commodity which is subject to many external forces, such as price and availability. Global gold stocks are increasing but the supply is dwindling. Gold mining companies are always looking for novel methods to optimise extraction and processing thereby reducing operating costs and maximising profit. The extraction and processing of gold involves complex chemical processing which results in large volumes of waste, including toxic tailings, and damage to aguatic and terrestrial ecosystems. Our research indicates that gold mines in Western Australia regularly enter an operational phase known as 'care and maintenance' where active mining is not occurring but the site is not yet formally closed. It is a mode generally used to reduce operating costs and overheads, whilst maintaining the option to recommence mining in the future. Sites in care and maintenance are often neglected and minimal rehabilitation is undertaken resulting in massive environmental liabilities and social issues. In worst case scenarios, companies simply mothball the site and they become abandoned or legacy sites. We recently quantified the disturbance footprint and environmental legacies around a representative sample of gold mines in the West Australian Goldfields region. Our results suggest that sites in care and maintenance are a potential emerging problem for regulators left carrying the can for the costs of rehabilitation.