Download Gauteng`s acid mine water time bomb

Gauteng’s acid mine water time bomb
On a site of the western basin decant near Krugersdorp, 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 Chief Executive of the Federation
for a Sustainable Environment.
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 river beds and surrounds.
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 plan didn’t say when this option will be
implemented by this date and by whom. 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. 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.
“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 % 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.
Source : The Star