Prioritization And Risk Assessment Of Groundwater Contaminants In South African Urban Catchments
Free (open access)
N. Z. Jovanovic, S. Maharaj, Y. Xu, H. Jia, R. Titus, B. Usher, I. Dennis, J. Pretorius & L. Cavè
With the exception of most developed countries, there is a worldwide lack of information on groundwater pollution in urban catchments. The objectives of this study were to generate an inventory of contaminants and associated sources for South Africa, and to develop a procedure for prioritization and risk assessment of contaminants in areas with limited data available. The study was carried out for the major metropolitan areas in South Africa. An extensive literature and Internet search as well as personal contacts were used to compile a comprehensive inventory of contaminants, their properties and associated sources. Due to lack of monitoring data, the prioritization was carried out by using information on types of industries and activities, from which the occurrence of specific contaminants was deduced. A simple model was used for ranking of priority contaminants, based on intrinsic hydrogeological properties of the sites and specific contaminant properties. The risk associated with priority contaminants was assessed with computer software using a tiered approach, based on the type and number of contaminant sources, the level of management, hydrogeological properties, exposure duration, toxicity and physio-chemical properties. The procedure developed is flexible enough because it allows the establishment of priority contaminants for specific areas with limited data available. Keywords: contaminant properties, contaminant ranking, contaminant sources, database, groundwater pollution, risk assessment, South Africa, urban catchment.
contaminant properties, contaminant ranking, contaminant sources, database, groundwater pollution, risk assessment, South Africa, urban catchment.