South Africa to start pumping acid water from disused mines

South Africa to start pumping acid water from disused mines

Kevin Crowley

Bloomberg

31 July 2013

South Africa will begin pumping acid water from disused mines that's threatening to flood Johannesburg, according to the Department of Water Affairs.

Equipment being installed in Germiston, east of Johannesburg, will be able to pump water from the city's central basin within the next four months, said Trevor Balzer, the department's acting director-general.

Acid water seeping from shuttered gold mines is rising under Johannesburg and, if left untreated, could pollute its water supply or flood the city. Iron disulfide, the "fool's gold" found in left-over rocks from gold mining, combines with rainwater to form sulfuric acid and other chemicals.

"We hope to get those pumps operational by October or November this year to keep the water level below the environmentally critical level," Balzer said in an interview yesterday. The government plans a tender for rights to treat the water toward the end of the year.

The government already pumps acid water from the western basin in the Witwatersrand, Balzer said. If levels rise too high it could contaminate water used for human consumption and agriculture, according to a 2010 report presented to the Inter- Ministerial Committee on Acid Mine Drainage.

The acid water under Johannesburg was formed during a gold- mining boom lasting more than a century from the 1890s. It has progressively filled underground cavities that lie under South Africa's biggest city, according to a 2011 study by the University of the Witwatersrand.

--Editors: Amanda Jordan, John Viljoen