Gauteng’s acid mine water time bomb
Johannesburg - She bends down and picks up, with her blood- red nails, what looks like a clump of soil. Mariette Liefferink, chief executive of the Federation for a Sustainable Environment, taps the edge of her car key against the lump. “Clang, clang, clang.” It sounds like she’s hitting a tiny pan.
The rock lump is actually made of metal oxide, here because of acid mine drainage. We are standing on the site of the western basin decant near Krugersdorp where these toxic waters have been flowing up to the surface since 2002.
Government intervention put a stop to the surface flow in late 2012, but high rains have meant that since December last year, some of the toxic water is again flowing untreated into our rivers.
The metal deposits are so substantial community members collect them and sell them for scrap metal. The eucalyptus plants around the water have little bumps and tumours on their branches. Their leaves are covered in black smudges and little white insects. “Wherever there is acid mine water we see these deformations on the plants,” said Liefferink.
Acid mine drainage occurs when water in large disused mines reacts with metals in the rock to form acidic solutions. The acid, which is in the form of sulphates in the water, makes the metals soluble. When they go out of solution and back to solids, they can coat riverbeds and surrounds.
Last week, the Gauteng department of agriculture and rural development launched a five-year plan to deal with the problem. But the plan is somewhat of a plan to make a plan. There has been no costing done and no exact decisions have been made. The department’s acting chief director of environment, Loyiso Mkwana, said the plan was a framework. “The plan didn’t say ‘this option will be implemented by this date by whom’,” he said.
“If nothing is done, the acid mine water is expected to reach the surface and decant at the lowest points in the central basin in the second half of 2015 and reach the surface and decant in the eastern basin in late 2016,” MEC for Agriculture, Social and Rural Development Nandi Mayathula-Khoza said at the launch of the plan. “Decant will be uncontrolled and is likely to occur at several identified points, as well as unexpected locations across each basin, owing to varying water levels and connectivity between the near-surface aquifers and voids.”
As has been done in the western basin, pumping and neutralising will occur in the other two basins. But the long-term solution needs to be more substantial.
Liefferink said she was heartened by the announcement of the plan and, although it didn’t yet have solid objectives, it was a step in the right direction.
“Acid mine drainage was denied for years. Now it’s accepted as a fact,” said Liefferink.
Liefferink became involved in environmentalism when she successfully challenged Shell, which wanted to build its operations opposite her house in Bryanston. “My strength in life is I’m a borrower from other people’s work and I’m a marathon runner,” she laughed.
After her fight against Shell, she was so involved in the effects of mining, she couldn’t stop. “I thought, this old woman can make a difference,” she said. Since then, her organisation has taken up lawsuits on behalf of affected communities, she advises the government and speaks on the topic throughout the world.
“What we are doing currently is addressing the symptoms, not the cause,” said Liefferink. The neutralisation treatment, which started in August 2012, takes the level of sulphates in the water from 4 500mg/litre to 2 500mg/litre. The World Health Organisation recommends sulphate levels of no higher than 200mg/litre for drinking water.
“That water is unfit for any purpose,” said Liefferink.
After the water is treated, it flows into a pit where more of the metals settle. The metals are then taken to another pit, called the West Wits. But this pit is not lined, so 30 percent of what is dumped returns to the water table. Liefferink said at the Human Rights Commission, where she is an adviser on acid mine drainage, they called it “revolving pollution”.
The taxpayer keeps paying for the same treatment, again and again.
As long as there are mine dumps, she said, sulphates continue to get into the water. But to treat acid mine drainage to the level of rehabilitating mines has been estimated to cost R30-billion, which would be paid largely by the taxpayer. - The Star