Physico-chemical and bacteriological assessments of shallow well water samples during the dry and rainy seasons

Abstract

There is need to study the impact of seasonal variations on well water quality especially in Ado – Ekiti metropolis as this will assist in creating awareness on groundwater quality for domestic consumption. The quality of groundwater obtained during dry and rainy seasons from 60 privately utilized hand-dug closed wells in Ado Ekiti metropolis were assessed. Physicochemical and bacteriological investigations were carried out according to required standards. The temperature, colour, turbidity, pH, total solids, chlorides, sulphate, calcium, magnesium, nitrate, and iron, which are physico-chemical parameters of the well water samples ranged from 24.7 to 25.6 °C, 4.1 to 7.3 HU, 3.7 to 6.9 NTU, 7.3 to 7.5, 95.7 to 211.1 mg/L, 38.6 to 74.6 mg/L, 34.3 to 64.9 mg/L, 24.3 to 49.4 mg/L, 48.1 to 89.0 mg/L, 0.4 to 0.8 mg/L and 0.05 to 1.0 mg/L respectively. Despite the fact that the parameters were within the acceptable ranges, bacteriological studies showed the presence of E. coli (ranged from 19.5 to 81.6 CFU) throughout the seasons, thus, individuals who rely on groundwater for their health are exposed to disease-causing organisms. Deductions from the correlation matrix equally, demonstrated the relative dependence of the parameters on one another as they variate according to the change in weather. Mostly during the rainy seasons, higher concentrations of the physicochemical and bacteriological parameters were observed than during the dry seasons, proving that the rainy seasons aid anthropogenic activities from the surface to transmit dissolved harmful waste materials to the subsurface which eventually finds its paths into the groundwater. Improper disposal of faeces, faulty soak-pits, latrines, dumpsites and burial grounds are part of the factors that contribute to bacteriological pollutants in the groundwater source.