Closed South African Gold Mines Leaking Water Into Johannesburg Supply

Johannesburg grew around some rich gold mines, but there's some new trouble from those old mines. Because the water pumps have long been turned off, the mines have been filling up with water. That water, mixed with mine residure, has become acidic and is starting to contaminate the city's water supply.

Acid mine drainage has plagued derelict mines globally for decades, but most of that damage has been in remote areas. The problem for Johannesburg is that the city has been built on top of its gold mines....

For more than a decade Mariette Liefferink from South Africa's Federation for Sustainable Development has campaigned for better environmental regulation.

When almost three years ago the last major pump removing water from the mines was switched off, she knew what was likely to happen.

Water would build up in the mines, it would mix with residue, turn toxic and then eventually start leaking. Slowly at first but leakage problems left unchecked would grow more costly and that's what's happening now.

Acidic water from the mines is already leaking into the city's groundwater and flowing into dams and rivers.

Given that Johannesburg is a major city, there'll almost certainly be a clean-up drive. There's little hope that the old mining companies will foot the bill, as the mines have been abandoned to the government. Said government has sent out an official to give the line that it's a highly complex problem because of the mines' abandoned status.