Acid mine drainage is South Africa's silent environmental catastrophe — a toxic inheritance from over a century of mining that the state has catastrophically failed to manage.
**The Problem**
When sulphide minerals in mine waste are exposed to air and water, they produce extremely acidic water laden with heavy metals, radioactive elements, and dissolved salts. This acid mine drainage (AMD) contaminates water supplies, sterilises soils, poisons food crops, and destroys aquatic ecosystems. On the Witwatersrand — where over a century of gold mining created hundreds of kilometres of underground tunnels and vast waste dumps — AMD has become an environmental emergency.
The Mpumalanga coal belt faces similar problems, with coal mining operations (many now defunct) leaching acid into waterways that communities depend on for drinking and irrigation.
**The Scale**
South Africa has 5,976 derelict and ownerless mine sites nationwide. The Council for Geoscience identified 1,730 as "high risk." Rehabilitation cost estimates range from R30 billion (Council for Geoscience, for high-risk sites only) to R47 billion (Human Rights Watch, for all derelict mines) to R100 billion (DMRE's own 2007 estimate for full rehabilitation at projected costs).
Three high-density sludge plants treat 185 megalitres of AMD per day in Gauteng — all at taxpayer expense. The R2 billion AMD treatment plant in Springs (Central Basin) suffered broken abstraction pumps in 2022, causing acid water levels to rise underground and threatening surface water systems.
**Government Failure**
The failure is not just one of scale but of will. In 2017, R60 billion was held by the DMRE for mining rehabilitation — but the funds sat unused due to regulatory constraints and bureaucratic paralysis. At the rehabilitation pace recorded in 2017, only 0.7% of derelict mines had been addressed. The DMRE's own estimate was that at the then-current pace, it would take approximately 800 years to rehabilitate all derelict mines.
Mining companies routinely close operations and walk away, leaving the rehabilitation burden to the state. The legal frameworks for compelling rehabilitation exist on paper but are barely enforced. A former Deputy Director General for Mineral Regulation appeared in court in May 2022 for misuse of mine rehabilitation funds — confirming that even the funds earmarked for cleanup are subject to corruption.
The consequence is borne by the poorest communities — those living downstream from abandoned mines, drinking contaminated water, and farming poisoned soil.