ACID-MINE DRAINAGE AT A COAL-MINE IN THE EASTERN TRANSVAAL, SOUTH-AFRICA

Several mines in the Witbank coalfield in South Africa are affected by acid mine drainage. This has led to a deterioration in the water qual ity in many surface streams. The Loubert Mine is one such mine. Hence, an initial investigation was carried out to determine the source of a cid mine drainage pollution and the associated hydrogeological conditi ons. The investigation showed that most of the acid mine drainage is e manating from old opencast workings which have been backfilled. Most o f the water from the backfilled area drains into control reservoirs. U nfortunately their capacity is limited, which means that water overspi lls and seeps from them. This water finds its way into a nearby stream , the water of which accordingly has an unacceptably low pH value and high sulphate content. The proposals advanced to control the problem b asically involve inhibiting the amount of water infiltrating the backf illed opencast area on the one hand and reducing the amount of water e ntering the control reservoirs on the other.