A comprehensive solution to the on-going Acid Mine Drainage (AMD) debacle has yet to be implemented despite the fact that the environmental critical level (ECL) in the western basin has been breached, resulting in surface decant. Johannesburg’s mining activities have enriched South Africa beyond measure. Unfortunately the exact price of these activities is only now coming to light.
Over the years, as mines were exhausted of their mineral wealth, they were shut down. Responsible mine closure and mine rehabilitation practices were unheard of in the early mining days. Thus, following the closure of a mine, water started seeping in which made contact with exposed sulphide minerals which oxidise in the presence of water and oxygen. This caused the water to become acidic which in turn dissolves other toxic metals such as uranium, cadmium, copper, zinc, arsenic, cobalt and nickel.
This toxic water is referred to as acid mine water or AMW and it this which is now seeping to Johannesburg’s surface. Depending on the area and nature of the mining conducted, this water can also contain radioactive particles. AMW falls under the category of an environmental catastrophe. Financial loss, property damage, injury and disease are but a few of the risks which stem from AMW.
In areas such as the western basin, AMW has already flowed into Johannesburg’s streams, dams and groundwater. The three main areas affected by AMW in Gauteng are the western, central and eastern basins, with the western basin being hardest hit.
In the West Rand, it is estimated that between 18 and 36 million litres of AMW is being decanted every day. The Lancaster Dam, Tudor Dam and Hippo Dam on the West Rand have already been contaminated; decant from the western basin has resulted in the Tweelopiespruit being classified as a Class ‘V’ river which means the ecosystem is completely destroyed and concerns are now being raised that the Cradle of Humankind and surrounding landowners could be affected.
Data from the Department of Water Affairs and the Council of Geoscience has also revealed that residential areas such as Kagiso, Khutsong and Randfontein are at a high risk of radioactive contamination.
A short term solution was implemented in 2011 by the Department of Water Affairs when the Trans Caledon Tunnel Authority (TCTA) was appointed to install pumps to extract AMD and upgrade water treatment plants. The TCTA requires R984 million and an additional R385 million per year for four years. To date, the Treasury has pledged R433 million.
In January 2012, a feasibility study to find long term solutions to the AMD crisis was launched by the Department of Water Affairs. The study, which carries a price tag of R17, 2 million, will be complete in February 2013. Meanwhile, a recent report by global management consulting firm AT Kearney emphasised the need for immediate action given that the western basin is already decanting and the central and eastern basins will reportedly start to decant within the next 12 months.
The fact of the matter is that many of the companies and people responsible for the current state of affairs have long since ceased to exist and attempting to obtain redress from any alleged historic wrongdoing in this respect would prove largely futile. Discussions between government and the various mining entities regarding the situation and costs are on-going. By the time a comprehensive solution is implemented, it may well be a case of too little, too late though.