Acid mine drainage threatens Gauteng's foundations

"Authorities on AMD," said Peter Flynn of the Environmental Law Consultancy, "now agree that in the Central Basin it can be found as near to ground level as 250m and it is expected to reach the ELC (environmental critical level) of 150m below the surface by September or October of this year.

"In the Western Basin the ELC has already been over-reached and water has been found at 0,88m below collar level, while in the Eastern Basin, where levels of 320m below the surface have been recorded, the ELC, which is put at 290m, is likely to be breached by November next year."

This situation, said Flynn, means that relief pumping and neutralisation of the kind now being carried out by Group Five, is absolutely essential. Group Five have a R319 million, ten and a half month contract to build a high-density AMD treatment works.

Need for a desalination process

"Now that the foundations of so much property are at risk, it is likely that a far wider spectrum of the public will be involved in trying to get an immediate solution. Any solution will obviously be expensive, but the situation cannot any longer be ignored," said Flynn.

In 2009, the auditor-general estimated that the cost of AMD treatment would top R30bn. However, said Flynn, the longer it takes for definitive action steps to commence, the more it will cost.

"The Group Five contact," said Flynn, "is a temporary and partial solution. South Africa needs a permanent and complete solution which involves not just the neutralisation of AMD but also the removing of salts (sulphates) from the neutralised water."

According to Mariette Liefferink of the Federation for Sustainable Environment, "Unless there is a desalination process by 2014/2015, the Vaal and Orange river systems would be so significantly harmed that the mining, agriculture and energy industries will suffer immensely".

For more information, go to www.telc.co.za.