Second, the acid dissolves metals previously bound up in ore and surrounding rock. When carried in runoff, the metals then enter aquatic environments where they can have devastating effects on aquatic life. This small, open-pit mine operated for a mere 3 years during the 1960s. However, it left a legacy of AMD that persists today. Largely as a result, the river, which used to support major salmon and steelhead runs, is essentially barren.
All methods involve ongoing expenditures, maintenance and monitoring.
Since acid-generation can continue for centuries after a mine is closed, treatment is required at many sites in perpetuity. The amount of acidic wastes continues to increase with each passing year. The major environmental impacts and risks associated with acid mine drainage necessitate a national clean-up plan and rigourous steps to minimize the creation of new AMD sites. Government of BC, Victoria. Feasby, G. and Jones, R.K. 1994.