There has been debate on how to treat it and who will pay for treatment, since the mines that caused the problem no longer exist.
About three years ago, the government finally took action. An interministerial committee was appointed and its first step was to instruct the Trans Caledon Tunnel Authority to install pumps on the West Rand, the highest-priority area, to treat partially about 23-25 megalitres a day of polluted water.
Government is still mulling longer-term solutions, but those will need billions of rand to implement.
Gauteng MEC for agriculture, social and rural development Nandi Mayathula-Khoza said at a media briefing in Krugersdorp on Wednesday that Gauteng's five-year plan, which has not been costed yet, supported at provincial and local government level the longer-term plans of the central government.
It was not intended to duplicate those plans.
The department has completed a Mine Residue Areas strategy that focuses on diffuse sources of pollution, such as tailings dams and surface mining. It is focusing on an awareness campaign and pilot projects on passive treatment of AMD.
Passive treatment includes placing wetlands in strategic areas, since it has been discovered that certain species of plants, like cattails or algae, can absorb some of the metals found in AMD.
Passive treatment also means preventing fresh water from flowing into the old mine workings, for example by building canals.
Loyiso Mkwana of the department says the province is committed to addressing this problem.
The findings of the research into different treatments will determine how much is needed for the full five-year plan. An estimated R36m will be needed in the first year, which will come from a variety of sources including government and the private sector.
Mariette Liefferink of the Foundation for a Sustainable Environment, an environmental activist who has pursued the issue for several years, said she needed more information about the plan before she could judge whether it was likely to be successful. Budgeting was critical as there was no point in having a grand plan if funds were not available for it, she said.