Effect of Seasonal Changes on Groundwater Quality in Sub-Urban Ibadan, Southwest Nigeria

The purpose of the study is to assess the levels of some physicochemical parameters and heavy metals in water sources and quantify their possible impact. Household water samples that include well water (n = 80) and treated municipal water (n = 3) collected from March 2019 to March 2020 were analysed for 11 physicochemical properties using instrumentation and classical methods. The estimated water parameters were first compared with standard values for drinking water and then analysed spatially using Inverse Distance Weighting (IDW) interpolation in ArcGIS software. Water quality indices were also computed as function of the potability of the water sampled. Through this study, it was found that the well water samples were slightly acidic (pH 6.7+0.61) while the concentration of nitrate (59.38 mg/L), sulphate (294.06 mg/L), cadmium (0.03 mg/L) and lead (0.13 mg/L) were above permissible limits in drinking water - 50 mg/L, 100 mg/L, 0.003 mg/L and 0.01 mg/L, respectively. The results indicates that more than 92% of the well water samples were unfit for drinking due to elevated concentrations of nitrate, sulphate, cadmium and lead. Findings from this study suggest prioritisation of clean water provision to residents in the affected communities to avert public health emergency.