As part of efforts to mitigate the decant of acid mine drainage (AMD) in the Witwatersrand basin, the Trans Caledon Tunnel Authority (TCTA) has invited applications from suitably qualified and experienced construction companies or joint ventures to tender for the construction of infrastructure for the Witwatersrand Eastern basin AMD project, near Springs.

The development of project infrastructure to extract and treat acid mine water and then convey the treated water to nearby water sources, was scheduled to start in late 2013.

The successful bidder will be responsible for the construction of shaft capping for Grootvlei Shaft No 3; building a structural steel pump station superstructure, including foundations; the procurement and installation of three deep-mine abstraction pumps; the construction of a 106-million-litre-a-day high-density sludge treatment plant; and the construction of a motor control room building, generator room and several short pipelines.

The contract would further entail roadworks and fencing and the supply and installation of medium- and low-voltage switchgear and other electrical components.

Interested parties have until September 17 to submit their applications.

The broad TCTA AMD project was aimed at employing a short-term solution to AMD in the Western, Central and Eastern basins of the Witwatersrand goldfields, with the primary objective of halting the decant in the Western basin and preventing the breach of environmental critical levels (ECLs) in the Central and Eastern basins.

The implementation of the project has been approved by Water and Environmental Affairs Minister Edna Molewa as an emergency works in terms of Section 103(2) of the National Water Act, while National Treasury had allocated R225-million for the implementation of the first phase over a two-year period.

TECHNICAL SOLUTION

The call for tenders came as Water Stewardship Council of Southern Africa trustee Dr Anthony Turton averred during the South Africa Water, Energy and Food (Sawef) 2013 forum, earlier this week, that, at a technical level, AMD had been solved, and that it now remained a question of funding, roll-out and commissioning.

“There's a substantial amount of stuff happening on the technology side of AMD mitigation at the moment. I would even suggest to you that AMD at a technical level has actually been solved, at least at desktop level.

“It's a question now of rolling it out and funding it and getting it up and running. But certainly from our understanding of the chemistry and the physics and engineering of AMD, I would say that we've pretty much got it sorted out,” he commented.

WESTERN BASIN

This assertion was reinforced on Wednesday by Water and Environmental Affairs Deputy Minister Rejoice Mabudafhasi, who told delegates at the Sawef conference that there had recently been a cessation in the decant of AMD-contaminated mine water in the Western basin.

“This has been made possible by the collaboration of not only government and its entities, but also of interested parties like some of our mining houses and private sector experts. This included access to land, refurbishment of some of the equipment, among others, but mainly a great deal of cooperation at different levels,” she commented.

Moreover, Molewa told Parliament in May that the Department of Water Affairs (DWA) was currently undertaking a second-phase upgrade of the Rand Uranium water treatment plant, in Randfontein, which would further increase the AMD treatment capacity in the Western Basin.

She added that the department had made “good progress” with regard to the challenge of AMD in the Witwatersrand area since the inception of an inter-Ministerial committee on AMD in 2010.

CENTRAL BASIN TREATMENT

In December, the DWA awarded JSE-listed construction company Group Five a R319-million contract for the construction of high-density treatment works, a pump station and monitoring shafts to tackle AMD in the Witwatersrand Central basin.

Molewa said the project was on schedule to start pumping water by November, which would result in the ECL not being breached.

Mining Weekly reported in February that the level of AMD in the Central basin was at 256 m and was expected to breach the ECL by September or October if pumping operations did not start.