South Africa Plots Pumping, Treatment To Keep Acid Mine Drainage Out of Water

摘要

About 1.16 billion rand ($145 million) will be needed over the next three years to pump and treat acid mine drainage to prevent the corrosive underground effluent from reaching central Johannesburg by the middle of 2013, a government official told a South African parliamentary committee.The drainage is coming from Witwatersrand, an area of three basins situated between Johannesburg in Gau-teng Province and the Vaal River. The region has been mined for gold for more than a century.Acidic drainage from mining activities, frequently carried out below the water table, can contain high levels of heavy metals such as cadmium, copper, cobalt,molybdenum, and zinc. The presence of these contaminants in water sources can affect the health, biodiversity, and safety of nearby communities, sometimes long after a mine's closure.To prevent the toxic drainage, water must be constantly pumped out of mines and treated. Earlier this year the Cabinet approved recommendations made by a panel of experts for tackling the acid mine drainage through flood control and pumping, among other measures (34 INER 299, 3/16/11). 'Severely Limited Time Frames' Cited. The Trans-Caledon Tunnel Authority (TCTA), a state-owned organization charged with funding and developing bulk raw water infrastructure for South Africa, presented a summary of the problem to the National Assembly's Water and Environment Affairs Committee Sept. 7. TCTA executive project manager Johan Claasens told legislators that solutions are being accelerated to cope with "severely limited time frames." He said R385 million ($48.8 million) will be needed annually from the National Treasury for the next three years to treat the basins.