Upgrade for acid mine water plant imminent

CONSTRUCTION on a R24m upgrade to a Witwatersrand acid mine water treatment plant is expected to begin in March, the Trans-Caledon Tunnel Authority said yesterday.

The new plant is part of the government’s “immediate solution” to the crisis in the region’s western basin. Acid mine water is already decanting into water courses on the Witwatersrand’s western basin and SA has been told that there is just less than a year to go before it decants into the region’s central and eastern basins, causing widespread ecological degradation, and compromising human and animal health.

The immediate solution consists of the extension of a Rand Uranium treatment plant so that it is able to treat up to 36 megalitres of water a day of acid mine water.

The plant could treat 12 megalitres a day, said the Authority, the state-owned bulk water provider the government has tasked with providing a solution to the problem.

A second phase, aimed at holding at bay a similar crisis in the rest of the Witwatersrand, put an estimated R924m price tag on securing the future of Gauteng’s water supply, the Authority’s spokeswoman, Thandi Mapukata, said. The Treasury had allocated R433m to the problem, leading to a shortfall of R491m. Ms Mapukata said final costs depended on which tender was approved.

The Department of Water Affairs was waiting for the publication of the Estimate of National Expenditure to see whether additional funds had been allocated, she said.

The second phase was aimed at keeping acid mine water below the “environmentally critical level” in the central and eastern basin, said the Authority’s executive manager of projects and implementation, Johann Claassen. This is a scientifically determined level at which it can be safely said acid mine water will not get into ground water.

Acid water was rising in both the central and eastern basins, but calculations were that the water was about 400m or more below the critical level on the central basin, and 600m or more below that on the eastern basin, he said.

Depending on rainfall, calculations were that the Authority had until at least September — at most December — to put the second phase into action in the central basin.

Ms Mapukata said “almost all” the mechanical structures needed for the western basin were in place. The two phases would operate in parallel until the environmentally critical level had been reached across the region, then the second phase would be used to keep the acid water at the critical level.

Department official Marius Keet said despite the first phase having been delayed by eight weeks from the initial date discussed, the department was satisfied with the Authority’s work so far. An 18-month feasibility study would look at ways to further fund the project.