Determining the effectiveness of landfill capping by reducing groundwater and surface water pollution
Modern day activities have the potential to place significant strain on the environment. These processes make use of natural resources which, in turn, render useful products and consumables. Other outputs which are produced along with these include unwanted products, such as waste. Waste may occur in various forms and may have detrimental effects on various receptors if not disposed of appropriately. Some sensitive receptors include surface water and groundwater bodies. Industrial contaminants which are not managed appropriately may have the potential to contaminate the surrounding land and in turn may lead to the contamination of the surrounding surface water and groundwater environments. Legislative requirements for the management of contaminated land have become more stringent. The onus lies on the owner of contaminated land to determine the significance thereof and take any and all necessary precautions in the management thereof. South Africa has established frameworks, which have been adopted from international standards, to follow when addressing contaminated land. The need to remediate contaminated land is determined by the outcome of a significance study. There are various remediation techniques which may be appropriate to specific contaminated land scenarios. The aim of this dissertation is to determine the effectiveness of implementing capping as a remediation technique. Determining the effectiveness will be done by evaluating the effect capping will have on the migration of a contamination plume. The natural aquifer parameters and associated major contaminants were obtained from historical data. A numerical model was developed to determine the extent of the contamination plume over time and to observe the effect that capping will have on mitigating the migration of the contamination plume. The results of the concentration and extent of the contamination plume for capping as a remediation technique is compared to the simulations of other remediation techniques. It has been found that the effect of capping as a remediation technique hinders the extent to which a contamination migrates. Capping is a relatively inexpensive remediation technique and should be used in conjunction with another appropriate remediation technique for most effective results. The modelling exercise revealed that capping contaminated land hindered the migration of the contamination to plume to an extent where no sensitive receptors would be at risk.