South Africa’s Department of Water Affairs (DWA) has confirmed that a feasibility study has been initiated to assess longer-term solutions for South Africa’s acid mine drainage (AMD) problem. The investigation began in December and should be completed over a maximum period of 18 months.

Responding to questions posed by Engineering News Online, the department said the study was expected to cost about R17-million and had been included in the DWA’s budget.

It would probe solutions over-and-above those identified as so-called ‘immediate’ and ‘short-term’ solutions for implementation by the Trans-Caledon Tunnel Authority (TCTA) across the Witwatersrand goldfields.

The emergency interventions were focused primarily on the Western basin, where acid water was already decanting into the Tweelopiespruit.

TCTA had entered into a strategic partnership with Rand Uranium to upgrade the miner’s treatment plant to 36 Ml/d from its current capacity of 12 Ml/d. Nearly all of the mechanical structures had been built, civil works were in progress and the enlarged plant was expected to be in operation during March 2012.

Additional short-term solutions would be commissioned in the Western Basin at a later stage to boost the efficacy of the emergency project in a bid to eradicate the prevailing AMD decant in the basin, as well as to prevent underground mine water levels from reaching the environmental critical levels (ECL) on the Central and Eastern basins.

On the Western basin the interventions were aimed at reducing the mine water level to below ECL over time.

A construction tender was issued by TCTA in October and closed on January 16. The bid evaluation was under way and TCTA was anticipating a contract award during February and for construction to start in March.

The National Treasury had allocated R433-million for the immediate and short-term projects. However, TCTA had cautioned that it could require R924-million to implement the projects, which would also require a yearly allocation of R210-million to operate.

It was uncertain, at this stage, whether these allocations would be confirmed by Finance Minister Pravin Gordhan, who was due to unveil government’s 2012/13 Budget on February 22.

The DWA stressed that the funding estimate was based on a due diligence review and that the final costs would be determined upon evaluation of tenders.

“Once a deficit is identified, the DWA will take the necessary measures to address any deficit,” the department said, adding that it was premature to comment on whether the funding gap would be closed in the February Budget.