Groundwater quality assessment near a Nigerian dumpsite

Abstract

Municipal solid waste collected in Nigeria are often disposed of in uncontrolled dumpsites and/or burnt in the open spaces and consequently causing significant pollution on surface water, ground water and the air. An investigational study was carried out on the level of pollution on groundwater near Gbagede dumpsite in Kwara state. Ground water samples, GW1, GW2, GW3 were taken at three different locations: 186 m, 290 m, and 326 m from the edge of the dumpsite. Physicochemical parameters evaluated include; pH, total hardness, Total Dissolved Solids, Total Suspended Solids, alkalinity, turbidity, Chemical Oxygen Demand, Biochemical Oxygen Demand, Dissolved Oxygen, Nitrate ion, Chloride ion, Sulphate ion, Electrical conductivity, Calcium ion and Magnesium ion using standard laboratory procedures. The results of the evaluations were compared with the World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ) to establish its suitability for human consumption. Results fell within the stipulated range of WHO and NSDWQ standard for drinking water. It was however observed that the water quality improves with distance from the dumpsite. Statistical analyses indicated mild differences among all the parameters tested for in the samples at 95% confidence level. Uncontrolled accumulation of leachates from the dumpsite may pose potential risk to the source of water for the community in the near future. It was recommended that the dumpsite be relocated from the current residential area.

Key Words: Groundwater, Assessment, Contaminants, Solid-waste, Water quality