Assessment of Leachate Effects on Groundwater and Soil from Nduba Land Fill in Kigali, Rwanda
Landfills are one of the groundwater pollution sources in Rwanda. Physical and chemical analyses of water samples were carried out to assure the magnitude of Nduba Landfill on ground water quality. Laboratory tests were conducted to get the results which helped us to study the assessment of leachate effect and to propose mitigation measures of Nduba landfill. The results showed that most of water were contaminated, where concentration of most physical and chemical parameters were above acceptable standard levels required by local and international standards for potable. The analytical results of leachates samples (Cu: 38.5 mg/L, Mn: 13.075mg/l, Zn:15mg/l, TP:4525mg/l, pH:8.52µS/cm, COD:7100mg/l, BOD:182.1mg/l, TN:5mg/l and Fe: 43.025 mg/L) showed that heavy metals are leached out from the MSW. The analytical results of groundwater from the wells located in the vicinity of Nduba landfill site (Cu: 2 mg/L, Zn:3.5-5.5mg/l, SO42-: 250-275mg/l, NO3-: 55-67.5mg/l,NH4+:1.5-2.25mg/l, COD: 39-53.4mg/l, Fe: 1.75-4.25 mg/L, Turbidity: 4.03-4.32NTU, pH:5.31-5.73µS/cm, Temperature: 21°C and BOD:20.7-21.6mg/l) compared to the World Health Organization standard (Cu:0.1mg/L,Fe:0.3mg/L,Zn:5mg/l,SO42-:200mg/l,NO3-:50mg/l,NH4+:1.5mg/l,Turbidity:<5.0 NTU and pH:6.5-9.2µS/cm) revealed that groundwater from the wells located in the vicinity of Nduba landfill site requires further physical chemical treatment to ensure their suitability for human consumption as the levels of some water quality parameters exceeded the EPA guidelines for drinking water. Designing a sanitary landfill was recommended to avoid effects of leachate on environment.