Assessing the Impacts of Mining Activities on Water Quality of Nyakabingo Stream and Nyabarongo River in Shyorongi, Rulindo District, Northern Province of Rwanda

This study assessed the impact of mining activities on water quality in the Nyakabingo stream and Nyabarongo River in Rwanda’s Rulindo District. It involved laboratory analysis of physicochemical parameters such as EC, turbidity, TDS, TSS, pH, nitrate, sulphate, and heavy metals (Al, As, Fe, Cd, Cu, Cr, Mn, Pb). Water samples were collected from untreated mining wastewater, treated wastewater, and upstream and downstream points of the river. Descriptive methods including documentary review, site observation, and interviews were used to understand mining practices. The results obtained for pH, heavy metals namely Mn, Cd, Pb, Cu, Fe obtained at the mining site and wastewater discharged from the treatment dams into Nyakabingo stream were not compliant to the requirements specified in RS EAS 1172:2014, the national standard on wastewater discharged on land and into water bodies. This also aligns with elevated levels for EC and TDS. In contrast, lower values complying to the requirements specified in RS 564: 2023 on specifications of ambient water, were obtained at upstream and downstream points on Nyabarongo river due to the long distance and the presence of streams that dilute the river water resulting in reduced concentration. This implies that the closer the water body is to the point of wastewater discharge, the more polluted it gets. The results have also indicated that the established treatment dams only helped to reduce the total suspended solids discharged in the environment while the level of chemical pollutants remained elevated.  The mining company should engage in further treatment of the wastewater prior to discharge into the environment to ensure pollutants in the wastewater discharged to not exceed tolerable limits on the applicable national standards. Key words : Mining Activities, Acid Mine Drainage, Standard Compliance, Water Quality, Chemical Polluants