The impact of acid mine drainage in the Witwatersrand Western basin.
Date
2016
Authors
Thulare, Thembi Ruth
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Abstract
The mining and industrial sector grew rapidly in South Africa during an era of less stringent environmental regulations resulting in a substantial amount of waste material released to the environment. The industrial wastes contain heavy metals, which, when in contact with water, re-dissolve and seep through the unlined tailing dumps draining directly into the environment (this contaminated water is generally called acid mine drainage (AMD)). In 2002, AMD water containing heavy metals such a uranium had started decanting from the Western basin, located below the Krugersdorp-Randfontein area. Communities in informal settlements, as they do not have access to clean and potable water use the untreated uranium contaminated water.
Research to evaluate the AMD impact on mining companies’ strategy, how to mitigate the cost of AMD and to review the environmental policies pertaining to the mining activities was conducted. The study focussed on the challenges experienced due to AMD particularly on companies within the Witwatersrand, Western basin and the surroundings. A qualitative methodology was used to collect appropriate data (interviews conducted eye to eye with the respondents) on how to mitigate the cost of AMD and its impact on mining and associated activities on the water regime in and around the Witwatersrand mining areas.
The research has indicated that South Africa’s future water balance paints a bleak picture characterised by severe water shortages. If AMD water is allowed to decant from the mines into the environment, an enormous amount of fresh water will be needed for dilution which presents a threat to water security, and ultimately inversely impacting the South African economy. This also has adverse impact on mining companies’ profitability; hence it is important that the mining companies have strategies to prevent risks associated with AMD. It is believed that treating the water to solve the problem of water security and at the same time having other by-products via the recovery of metals and reagents from AMD could be a viable solution to water pollution.
The regulatory standards and policies in combating the challenges caused by AMD have been proven adequate in the opinion of the experts in the literature. Although standards have been established to set maximum acceptable levels of contaminants that can be released into the environment; mining companies find it difficult to achieve the set standards due to the legacy left by the mining activities that happened more than a century ago and mines that go into liquidation and abandoned their environment liability once closed down. These old abandoned mines significantly contribute to AMD; hence, it is in this regard that the treatment of AMD has to be done by existing mines in collaboration with the government.
Given that South Africa is a water scarce country, AMD water is seen to present an opportunity as a source of water for South Africa. Treating the AMD water to drinkable standards is the ultimate goal for the mining sector, which could in addition improve the water supply in South Africa. Hence most of the mining industries are including plans to build treatment plants into their strategy, which would deal with the environment problems, while creating jobs at the same time.
Description
MBA
Keywords
Acid mine drainage,Mine water -- Environmental aspects,Mineral industries -- Environmental aspects -- South Africa.