The department of water affairs said it is confident a new pump station will be in place in time to stop acid mine water rising up
below Johannesburg and causing an environmental disaster. But it is going to be a close-run thing.
"If nothing is done, water will start decanting [from the so-called central basin, under the city] and contaminating groundwater in 17 months," senior water affairs official Marius Keet told members of Parliament's land and environmental affairs select committee.
To prevent this, a new pumping station and upgrades to an existing high-density sludge treatment works were urgently required.
"According to the information available, 13-months lead time is required for this. So if government... decides now to do something,
in 13 months you can have a pump station," Keet said.
This means, starting immediately, government has a four-month window in which to take action. Asked after the briefing if her department would meet this deadline, acting director general Nobubele Ngele assured it would.
"The way we've paced our timeline, we'll accommodate the four-month period... We're pushing for this... In three months time, Cabinet will have made a decision," she said.
Costs to run into the millions
Water Affairs Minister Buyelwa Sonjica recently announced the setting up of a high-level technical task team to tackle the acid
mine drainage problem, particularly in the Witwatersrand area.
Keet said the cost of building the pump station and refurbishing the existing treatment works would total R180 million. The department was also looking at running a pipeline through to the treatment works from the region's western basin, where acid
mine water started decanting from mainly ownerless mines in 2002.
The cost of this pipeline would be R40 million.
Earlier, he told members the water level on August 13 in the basin below Johannesburg was 558 metres below the surface.
"The current rate of rise is 0.35 metres a day, but it can go up to 0.9 metres a day in summer."
Worst case scenario: sinkholes, earth tremors
Keet said the recommended "environmental critical level" for the rising acid mine water, which he defined as "a water level determined to protect water and environmental resources", was 150 metres below surface.
Asked later what the environmental implications would be, should acid mine water rise substantially above this 150 metre level, Keet said there could be "seismic effects", including earth tremors, and the possible formation of sinkholes.
The problem of acid mine drainage, referred to as AMD, is not onfined to the Witwatersrand region. Other affected areas include
the Mpumalanga and KwaZulu-Natal coalfields, and around the copper ines near O'Kiep in the Northern Cape.
AMD is associated with low pH, high sulphate levels, elevated evels of heavy metals, and, in some areas, radioactivity. It has been described as "the biggest-ever environmental hallenge" South Africa has faced. - (Sapa, August 2010)
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