Physicochemical and Microbiological Assessment of Selected Hand-Dug Wells for Water Quality in Ilesa Metropolis, Southwest Nigeria

The present study investigated the physicochemical and microbiological assessment of selected hand-dug wells for water quality in Ilesa metropolis. The aim was to assess the groundwater quality. Twenty-five (25) hand-dug wells were randomly selected and water samples were collected four times spanning through the rainy and dry seasons. Physical parameters (ambient air temperature, water temperature, colour, turbidity and total dissolved solids), chemical (pH, conductivity, calcium, magnesium, total hardness, chlorides, sulphates, phosphates and nitrates) and microbiological parameters (total heterotrophic bacteria count, Escherichia coli and total heterotrophic fungi count) of the samples were examined. The data obtained were subjected to relevant statistical analysis. Results showed distinct seasonal variation in ambient air temperature, water temperature, pH and magnesium with highly significant different values at (p ˂ 0.01). Total hardness and sulphates concentrations had high significant different values in the dry season than in the rainy season (p ˂ 0.05) while the total heterotrophic bacteria count was significantly different at (p ˂ 0.001). The bacteria species isolated from well water samples were susceptible to pefloxacin and gentamicin. Comparing with international guide levels for drinking water, water samples were poor and unsuitable for drinking. The study concluded that the presence of multiple antibiotic resistant micro-organisms indicates a serious health hazard to the consumers of water obtained from these wells.