Johannesburg, South Africa — MININGREVIEW.COM — 05 March, 2012 – Public meetings to approve emergency measures for the treatment of acid mine water on the Witwatersrand will be concluded within the next week.
A public meeting is to be held on Saturday at the Springs Country Club. Fin24 reports that in this basin toxic water is flowing out at a rate of 82 megalitres a day.
The rising acid water in the Central Basin has reached a level of about 200m below the critical environmental level.
The critical environmental level is where the acid mine water starts to erode underground dolomitic structures, and shortly afterwards starts to pollute the natural groundwater as well as points of egress, such as fountains, according to Fin24. This process takes several months, after which the water eventually begins to emerge on the surface.
The environmentally critical level in the Central Basin is 150m below the surface at the South-Western vertical shaft of the old ERPM mine in Germiston – the shaft selected years ago by Western Utilities ¬Corporation as the best point for the acid mine water in the Central Basin to be pumped out and properly purified to the quality of drinking water.
The acid water is currently 350m below the surface at the South-Western vertical shaft.
The Caledon Tunnel Authority, which acts as the state body to deal with the impending crisis, proposed that three water installations be built rapidly to pump out the rising water, treat it temporarily with lime and then release it into the environment.
But environmental groups are upset because this process merely reduces the acidity of the water and does not remove the toxic heavy metals it contains.
In the Western Basin – where it is hopelessly too late to prevent pollution because the acid water has been flowing out since October 2002 at a rate of 15.7 megalitres a day – the Caledon Tunnel Authority now wants to construct an installation such as this on the premises of the Randfontein Estates Mine, where the water is being treated with lime and then discharged into the already contaminated Tweelopiespruit.
Public meetings where the public could comment on these proposals were held in Krugersdorp last weekend and in Germiston on Friday to discuss the Central Basin installation.
It is predicted that the eventual outflow will be 57 megalitres a day. The new plant is envisaged close to the previous one used by DGRGold to counteract the problem by pumping out and treating the water at the South-Western vertical shaft. These pumps ceased operating because the shaft was closed down by mine inspectors after a mining accident.
In the Eastern Basin a new installation is being planned at the old Grootvlei No 3 shaft.
A public meeting is to be held on Saturday at the Springs Country Club to seek the necessary permission.