The Gauteng Department of Agriculture and Rural Development (GDARD) has, in collaboration with peer public-sector institutions, launched a five-year framework plan aimed at halting the decant of acidic ground and surface water emanating from disused mines in the Witwatersrand (Wits) Basin.

“If nothing is done, the acid mine water is expected to reach the surface and decant at the lowest points in the Central Basin in the second half of 2015 and reach the surface and decant in the Eastern Basin in late 2016,” MEC for Agriculture, Social and Rural Development Nandi Mavathula-Khoza cautioned at the launch of the plan last week.

“Decant will be uncontrolled and is likely to occur at several identified points, as well as unexpected locations across each basin, owing to varying water levels and connectivity between the near-surface aquifers and voids.”

The Gauteng Long-Term Plan for the Management of Acid Mine Drainage (AMD) would be aligned with ongoing national efforts to manage AMD and would be informed by research around “active” treatment options, such as pumping, sludge management, neutralisation and congress control, and “passive” options, such as allowing natural wetlands to filter and purify acidic decanted water.

The provincial AMD committee would consist of representatives from the GDARD, the Gauteng Planning Commission, the Department of Cooperative Governance and Traditional Affairs, local municipalities, research institutions and universities, meeting quarterly to discuss progress made on the implementation of the five-year strategy.

This committee would be responsible for developing a provincial AMD implementation framework that would identify and approve appropriate funding mechanisms, outline the resource management approach, identify the implementing agency and devise a “partnership approach”.
“This partnership approach must determine the best way to engage private-sector partners including research and academic institutions,” Mavathula-Khoza noted.

The committee would also be tasked with identifying opportunities for job creation within the five-year plan and ensure the development of a communications plan to keep the public informed as to the progress of the interventions.

“This communications plan should also include the possibility of having to communicate any potential danger if the decant is uncontrollable…. It is important, however, to let the people of Gauteng, especially the people of the West Rand, know that they are [currently] safe with regard to AMD,” Mavathula-Khoza stressed.

While the cost of the five-year programme was yet to be defined, GDARD acting chief director of environment Loyiso Mkwana said some R36-million would be required in the first year.

“The costing and funding model still needs to be worked out and we have no timelines yet, as this is still a framework plan that needs development,” he commented.

The funding mechanism had yet to be determined, but three possible institutional arrangements had been identified as possible sources of funding.
The first of these was for municipalities in the affected basins to treat the water and sell it to water consumers. However, this alternative presented several problems, as it introduced a “fragmented approach to a regional problem”, and would mean that the water consumers of only three municipalities would bear the cost of treatment, while all consumers using water sourced from the Vaal river system would benefit, namely the West Rand district municipality, the City of Johannesburg and the City of Ekurhuleni.

“This funding option would also not holistically solve the other problems of water losses and unlawful abstraction,” Mavathula-Khoza said.
A second financing option would see Rand Water treating AMD and selling it as potable water to consumers. This option, she explained, had the advantage of a regional approach being taken while allowing treated water to be integrated into the existing distribution system.

“However, this would also not deal with unlawful extraction and end-users outside of the Rand Water area of supply would benefit without bearing any of the costs,” Mavathula-Khoza noted.

A final funding option was that the Department of Water Affairs, through the National Water Resource Infrastructure Branch, took full financial responsibility, which would involve developing an integrated approach to capital expenditure and tariff-setting along the entire value chain.

Several AMD interventions had already been implemented, including the establishment of an AMD treatment plant in the Western Wits Basin, which had experienced AMD discharge since 2002.

This followed the establishment of an inter-Ministerial Committee, which was formed to advise government on potential AMD treatment strategies and would now also work in conjunction with the proponents of the provincial five-year plan.

“The Western Basin is the highest priority, as it has been experiencing free decanting for 12 years. The immediate solution in the Western Basin is operational and the plant is treating between 23-million litres and 25-million litres of acid mine water a day. The untreated decant has now stopped and further initiatives for the basin are planned [as part of the five-year strategy],” Mavathula-Khoza outlined.

The GDARD had also completed a Gauteng Mine Residue Areas strategy, which was currently being implemented and would include an AMD awareness campaign and the development of a pilot project on “passive” treatment.

The department also commissioned the Council for Geosciences to construct a canal in the Western Basin to prevent the ingress of surface and groundwater further underground, thus reducing pumping costs.