Effect of small scale gold mining on rivers Jimi and Nyame at Obuasi

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Small scale gold miners in Ghana rely mostly on water resources for gold processing resulting in the release of harmful substances that impact negatively on water quality. The purpose of this study was to examine the heavy metal content and physicochemical parameters of River Nyame and River Jimi at Obuasi and its environs in Ashanti Region of Ghana. To achieve these objective, standard methods for portable water quality were used to examine the physicochemical parameter whilst Atomic Absorption Spectrophotometer (AAS) was used to determine the concentrations of metals in the sampled water. The study found that most of the concentrations of physicochemical parameter such as, temperature, pH, electrical conductivity (EC), dissolved oxygen (DO), and metals such as mercury, zinc, lead, and manganese, as well as toxic anions like Nitrate (NO3− ), Sulphate (SO4 2−) and Phosphate (PO4 2−) were within the prescribed limit for water quality standards. However, the study identify higher concentrations of Arsenic slightly above the prescribed water quality guideline values and also realized that, the concentration of cadmium had also reached the maximum prescribed permissible limit of 0.003 mg/L given by World Health Organization. Retrospective analysis shows that the pH of the water bodies had influence on the concentration of metals such as zinc, arsenic, and manganese by altering their availability and toxicity. Although mitigation efforts have had a limited impact, it is expected that the policy recommendations of this study if adopted and strictly adhered to will help reduce, if not completely ameliorate the environmental ramification of small scale mining in Ghana.
A thesis submitted to the Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi in partial fulfillment of the requirement for the award of Master of Science Degree in Environmental Science.
Mining, River Jimi, River Nyame, Obuasi