Acid Mine Drainage in South Africa: Development Actors, Policy Impacts, and Broader Implications

However, mining activities are also associated with environmental contamination such as acid mine drainage (AMD). AMD is highly acidic water, usually containing high concentrations of metals, sulphides, and salts as a consequence of mining activity. The major sources of AMD include drainage from underground mine shafts, runoff and discharge from open pits and mine waste dumps, tailings and ore stockpiles, which make up nearly 88% of all waste produced in South Africa. Drainage from abandoned underground mine shafts into surface water systems (decant) may occur as the mine shafts fill with water. Although the chemistry of AMD generation is straightforward, the final product is a function of the geology of the mining region, presence of micro-organisms, temperature and also of the availability of water and oxygen. These factors are highly variable from one region to another, and, for this reason, the prediction, prevention, containment and treatment of AMD must be considered carefully and with great specificity.