South Africa’s Trans-Caledon Tunnel Authority (TCTA) reports that it is making some progress in implementing emergency and near-term projects designed to deal with the problem of acid mine drainage (AMD) arising on the eastern, central and western basins of the Witwatersrand goldfields. But in a ‘status update’, released on Thursday, the State agency again cautions that the capital set aside for the implementation of the so-called ‘Phase 1’ projects is inadequate.

These ‘Phase 1’ interventions aim to prevent the acid water from rising above the so-called environmental critical level (ECL) across the various basins, while drawing the level below that level in the western basin, where the ECL has already been breached.

In fact, TCTA describes funding by the government to meet AMD costs as “not feasible or desirable”.

A due diligence review undertaken last year by BKS and Golder Associates, indicated that the capital costs associated with Phase 1, inclusive of a 15% contingency and escalation, would be R924-million. But TCTA was initially allocated R225-million, which National Treasury increased by a further R208-million after both TCTA and the Department of Water Affairs (DWA) made representations.

In other words, the funding shortfall is currently estimated at R492-million for the project, which comprises: the installation of pumps to extract water from a mine void to on-site treatment plants; the construction of an on-site water treatment plant in each basin with the option of refurbishing; and upgrading the existing plants owned by the mines and the installation of infrastructure to convey treated water to nearby water courses.

The allocations also do not cover estimated yearly operating costs of R210-million for an intervention TCTA acknowledged to be a mere “interim solution to prevent an environmental catastrophe”.

As part of the ‘immediate’ solution to the decanting of AMD on the western basin, TCTA had entered into a partnership with Rand Uranium to upgrade the miner’s treatment plant to a level where it would be able to process 36 Ml/d, instead of the current 12 Ml/d.

After September, additional capacity will be introduced under what is described as a ‘short-term’ solution. Tender documents for this short-term solution were issued in October and closed in January. TCTA expects the evaluation of the bids to be completed in February and for construction to begin in March.

TCTA also acknowledges that water released into the river system after implementation of Phase 1 may still contain high salt levels, which requires dilution from expensive and scarce fresh water sources to mitigate the impact.

The Democratic Alliance’s shadow water and environmental affairs minister Gareth Morgan says the update appears to be in line with earlier communication from the agency. However, it also contains some “gentle admissions” that the long-term solutions have not been agreed, as well as the fact that Phase 1 will not treat the water to a level where it is no longer a threat to the environment.

However, he tells Engineering News Online that it is positive that the TCTA is beginning to communicate openly on the matter. That said, he is eager to see progress on the longer-term solution, as well as the introduction of mechanisms to make the treatment process increasingly self-funding.

The current taxpayer-funded approach was unlikely to be sustainable, particularly in light of the fact that yet more interventions were needed, while the operational costs appeared to be a material factor. But Morgan is also skeptical of the suggestion of the imposition of an environmental levy on the mines to pay for the AMD.

The DWA is currently undertaking a feasibility study to determine the long-term sustainable solution, but it is not yet clear when that study will be finalised and what funding model will be incorporated.

For the immediate future, it is likely that Finance Minister Pravin Gordhan may need to secure even more resources, not only to fund the capital cost of Phase 1, but also to begin paying for the operational expenses associated with the clean-up.