Evaluation of the sustainability and environmental impacts of mining in the Rustenburg Region

Ph.D.This study evaluates the environmental impacts of platinum mining in the Rustenburg region and the development of the region into a sustainable society, post the Johannesburg World Summit on Sustainable Development (WSSD) held in 2002. The region has been the location of intensive mining and metallurgical processing of platinum group minerals and chromium for more than three decades. Many studies have focused on the impacts of individual mines on their immediate environment and the sustainability of their operations. This study takes an holistic approach, looking at environmental changes across a larger area and the evaluation of the implementation of sustainable development principles in the region in the decade following the Johannesburg WSSD summit, using a multi-disciplinary approach. The debate concerning a suitable definition for sustainability within the mining context was followed through a literature review. In a strict sense, there is a paradox - mining is inherently unsustainable because of the finite, non-renewable nature of mineral resources. To resolve this paradox, two concepts of sustainability emerged: weak sustainability, in which economic capital replaces natural capital; and strong sustainability, prevention and minimising any environmental damage. These two concepts of sustainability were examined within the mining context, and the conclusion reached in this study is that the weak sustainability concept is more realistic and useful in the mining industry, since diverse environmental impacts cannot be avoided during mineral extraction. However, this does not mean that the environmental impacts should be neglected; instead they should be minimised. Sustainability is then achieved when the total amount of capital (i.e. both natural and economic) is constant or increases. Medium-resolution satellite data (Landsat and ASTER images) were used to map land cover/use to quantify the changes between 1973 and 2007, over 205 209 hectares of the Rustenburg region. The most important land cover/use change was the conversion of grassland to agricultural lands and mining areas. Changes in mine tailings storage facilities in terms of size and vegetation status were analysed. Landscape metrics (fragmentation index) were used to interpret the statistics derived from the land cover/use change to give an indication of the functioning of the ecosystem. Tailings samples were collected from two tailings storage facilities. Grain size analysis of the tailings samples was conducted to determine the percentage of particles with diameter ≤2.5 μm and ≤10 μm. Chemical analyses of samples were performed to determine elements of major concern because of their enrichment in the tailings and their potential toxicity. An analysis of the weather data acquired from the weather station located within the area was presented in the form of wind roses. Information on particle-size distributions obtained from the tailings samples and local meteorological data were used to carry out a detailed dispersion model of fugitive dust from mine tailings storage facilities