West Rand acid water to be tackled

2011-09-07 20:45

Cape Town - Treatment of acid water pouring out of old mine workings near Krugersdorp on the West Rand will start within three months, MPs were told on Wednesday.

By next August, pumps would be in place to begin dropping the water level in a honeycomb of shafts and tunnels, Trans-Caledon Tunnel Authority (TCTA) executive Johann Claassens said.

This would effectively stop the outflow, he told members of Parliament's water and environmental affairs portfolio committee.

The TCTA was appointed in April this year - by Water and Environmental Affairs Minister Edna Molewa - to install pumps, build plants and treat the acid mine water decanting from the so-called Western Basin.

The same authority is also looking at solutions for the Central Basin (under Johannesburg) and the Eastern Basin (below the town of Nigel), where acid water levels are rising.

If the problem was not tackled, the acid would also start overflowing in these areas.

Claassens said the immediate solution to the problem in the Western Basin was to upgrade the "fairly dilapidated" Rand Uranium treatment plant to handle 36 megalitres of acid water a day.

Neutralised

"That should be sufficient to stop the... decant, as it is now ," he said.

Treatment of the acid water would start in November-December.

The treated water would continue to be discharged into the Tweelopiespruit, which flows through the Krugersdorp Game Reserve.

Asked about this by committee chairperson Johnny de Lange, Claassens said the water would be neutralised, but not desalinated.

"Treasury is going to be very unhappy with that," De Lange told him, adding that it appeared the plan was to continue pumping "bad water" into the spruit.

Treasury is in the process of approving a budget to deal with the acid mine drainage problem.

Earlier this year, a report by a Cabinet-appointed team of experts recommended that consideration be given in the medium to long-term to reducing the salinity of the discharge water.

Claassens said once a new high-density sludge plant had been built on Randfontein Estate East, and pumps and pipework installed in Rand Uranium's 8 shaft, it would take from August next year to June 2013, to drop the water level in the Western Basin to below the environmentally critical level of 165 metres.

Highly toxic

Sludge is formed during the process of neutralising acid mine water.

It is highly toxic, and contains heavy metals. The TCTA plans to pump the sludge, via a pipeline, to a disposal facility at West Wits Pits.

Water affairs official Marius Keet told the committee the acid mine water level under Johannesburg, in the Central Basin, was now 628 metres below the city.

The environmentally critical level is 306 metres.

Pumping and treatment of water from this basin would also begin in August next year, he said.

Claassens said the R225m set aside by government to deal with the acid mine drainage problem on the Witwatersrand would not be enough.

He told the committee immediate and short-term capital costs for schemes in the three basins would total R924m.

On top of this, were operational and maintenance costs of R535m, bringing the total cost to R1.459bn.

He warned that the timeline for putting in place various parts of the scheme was tight.

Urgent decisions needed to be made on the funding so that contracts could be awarded to start the work.

"We have from now until November to get clarity on the funding," Claassens said.

Earlier, De Lange criticised the department of water affairs for its apparent failure to re-issue legal directives on pumping mine water to mining companies.

The directives expired in January this year.

"Letting the directives lapse, on how the mines should deal with water... I just don't know how people think... it just bothers me," a clearly exasperated De Lange said.

- SAPA