Source: Mail and Guardian

What do you fear most -- nationalisation or acid mine drainage (AMD)? Chances are, particularly if you live in Gauteng, you're more worried about the latter. You may be able to survive the pernicious effects of nationalisation, but a water supply turned toxic is no basis for any future.

There are two main worries, one being that acidic underground water is rising, turning lakes into dead sludge and threatening tourist attractions such as Gold Reef City. Much of the Witwatersrand, it would appear, swims on a corrosive underpin.

The other worry, though, is that the government does not appear to have a plan to deal with AMD. The miners who created the problem in the first place, some as long ago as 120 years ago, have packed their bags, leaving hundreds of open mine shafts and tailings dams which, in some cases, have sufficient radioactivity, to make the area unsuitable for human habitation.

Last week the government made a long-awaited report available which it has commissioned for an inter-ministerial committee tasked to deal with the AMD issue. It says AMD is "formed by a series of chemical reactions which occur between water [and] sulphide minerals such as pyrite and oxygen, which combine to form an iron-rich sulphuric acid solution".

The report notes that gold mining on the Witwatersrand has created an interconnected system of tunnels. "As a consequence, as mines within a basin stop operating and stop pumping water from their underground workings this water flows into adjacent mines, increasing the volume of water which the adjacent mines need to pump.

"Eventually, the last mine in a basin will cease operations and stop pumping, after which the underground workings will flood and the water level will continue to rise until it reaches the surface and decants to a low-lying shaft or other pathway(s) to the surface."

No pumping in the central basin
No pumping has taken place in the central basin, the largest on the Witwatersrand, since 2008, the report says. The water level is rising by about 59cm a day. At this rate, it will have risen to the surface at the ERPM mine on the East Rand by March 2013, sterilising still exploitable gold reserves at a depth of 400 metres.

"Of even greater consequence, it will not only have flooded the shallower underground tourist facilities at Gold Reef City but also compromised the shallow groundwater resource associated with the dolomitic strata located to the south-east of Johannesburg," the report says.

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