Abstract
Abstract : Adequate and sustainable urban water supply is imperative for human consumption, for meeting different water-use activities and supporting economic development. Water supply must be managed to meet demands of population growth, development and socio-economic priorities in an equitable and sustainable manner. Mining operations contribute positively to economic growth and the high rate of urbanisation but can have negative environmental impacts. Water provision in mining regions can be challenged with limited access to freshwater and deteriorating water quality. This is compounded by drought and impact of climate change. The aim of the research was to examine the quality of water and provision of water with a view to generate suggested improvements for municipal water supply in water scarce mining regions. The study was conducted in the mining city and towns of Goldfield municipality, First Coalfield Municipality and Second Coalfield Municipality in Gauteng and Mpumalanga Province, South Africa. These areas derived their drinking water from dams linked to the Olifants River. Previous studies had estimated that approximately 44 Ml/d of acid mine drainage is discharged into the upper Olifants River catchment. In this context this research assessed the water resources based on multiple and comprehensive data on water quality determinants. The water quality data was obtained from the Department of Water and Sanitation and comprised water quality determinants for the year 2003 to 2011 for the chosen geographical areas. Within the catchment area the water had been sampled at defined locations according to national water quality monitoring standards. Water samples are taken biweekly through a grab sampling method on all sampling stations. The data comprised of pH, electrical conductivity, total dissolved solids, chloride, total alkalinity, fluoride, calcium, magnesium, sodium, iron, manganese and aluminium as the water quality determinants. The research methodology was based on historical trend analysis of water quality determinants (compared to legal thresholds) in the catchment area, in the dam, and before and after the water purification plant. Additionally, a questionnaire was used to understand the challenges in water supply and to evaluate the uptake and preference of water augmentation strategies within thee municipalities. The Research made new contribution to knowledge in terms of: (i) a robust and quality determinant independent approach to use process capability index to proactively monitor water quality determinants and to make better effective use of existing water quality data. Extracting essential information to avoid violating water thresholds in the future and to aid advance action, (ii) a set of strategies that can be used by the municipalities to augment drinking water supply. This was developed by drawing from international best practice and refined by the assessment of stakeholders and local water provider experts It was found that the water from the catchment area was contaminated when compared with the main collecting stream. This is a critical situation for local communities who may consume or use the water directly from the catchment area. It was also found that the municipal water treatment system was not effective in removing certain total dissolved salts (TDS). While this is not critical when the total dissolved salts are below legal thresholds for drinking water, the capability of the water purification systems will need to be updated to consider possible increase in total dissolved solids above threshold levels. This requires more stringent monitoring of TDS and predication of future levels. This is a critical and significant finding that should be on the risk register of water service providers. The above contributions are important for municipal authorities responsible for water supply, for government’s strategic support of water investments and for researchers worldwide facing the challenges of augmenting water supply in water stressed regions.