Cape Town – 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 on Tuesday.
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 Sapa 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.
Acid mine drainage
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 told Sapa the cost of building the pump station and refurbishing the existing treatment works would total R180m.
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 owner less mines – in 2002.
The cost of this pipeline would be R40m.
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.”
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 sink-holes.
The problem of acid mine drainage, referred to as AMD, is not confined to the Witwatersrand region.
Other affected areas include the Mpumalanga and KwaZulu-Natal coalfields, and around the copper mines near O’Kiep in the Northern Cape.
AMD is associated with low pH, high sulphate levels, elevated levels of heavy metals, and, in some areas, radioactivity.
It has been described as “the biggest-ever environmental challenge” SA has faced.