Acid mine water, the result of groundwater flowing through underground shafts, is decanting from an old uranium mine and rising by half a metre a day beneath the city of 7 million people. Mass evacuation of informal settlements is one of several recommendations in a government-commissioned plan drafted in June to deal with 380 acid mine dumps - many of them radioactive.
Uranium is often mined as a byproduct of gold in South Africa and it is estimated that some 800 kilometres of tunnels exist underneath Gauteng left over from more than century of underground mining.
Business Times reported on Saturday a peer-reviewed report by Anthony Turton, a prominent South African water scientist, reveals that radiation levels at Tudor Shaft suggest that the country faces a localized environmental crisis that can be compared to Chernobyl.
The Mail & Guardian reported last week the acid mine drainage is coming back to burn the industry now. The mining companies have put together a R70 million ($9 million) project and appointed a cost-recovery company to solve the legacy problem and help provide extra potable water in the Gauteng province.
Johannesburg is one of the 40 largest metropolitan areas in the world, and is also the world's largest city not situated on a river, lake, or coastline. South Africa accounted for 12% of the world's gold production in 2005, though the nation had produced as much as 30% of world output as recently as 1993. Almost 50% of the world's gold reserves are found in South Africa according to the US Geological Survey.
The Top Star mine dump was constructed from 1899 to 1939, reaching a height of 50 meters and containing 5.1 million metric tons of chemically processed mine waste. In the early 1960s, Top Star was converted into a drive-in movie theater, which showed movies until 2006, when it was shut down by DRD Gold to extract latent gold in the mine waste. The mine dump's dramatic height within Johannesburg's urban core offered spectacular views of the Central Business District.