ABSTRACT
Regulations regarding the standards to which opencast coal mines and coal discard dumps should be rehabilitated are becoming increasingly stringent. This has placed the coal mining industry and the design engineers of these measures in a predicament, as costs of the rehabilitation are becoming prohibitive. The paper documents a five-year pilot scale experiment to develop sufficient data to calibrate a numerical model that would accurately predict recharge through a natural soil cover. Ten test cells were constructed using different natural soil cover configurations. The cells were instrumented thoroughly to ensure a complete understanding of the performance of the soil cover. The results of the experimental data, and its relevance in terms of the design paradigms, are discussed. Further, shortcomings of existing numerical models have been identified. The paper also presents a geochemical assessment of the leachate water quality database. It concludes with design recommendations for rehabilitation using natural soil covers.
