Regional Pattern of Quality Characteristics of Groundwater in Oyo State, Nigeria Using ANOVA and Duncan’s Post Hoc Test

Investigations into the regional distributional pattern of groundwater quality characteristics is important as it enhances the understanding of the general spread of the quality parameters of groundwater both temporally and spatially so that appropriate and relevant but holistic remedial solutions could be taken to mitigate any anti-human health observations. The regional pattern of groundwater quality was investigated in Oyo State, Nigeria. Samples of well water were taken from 124 rural areas across 25 out of 30 local government areas in Oyo State. Laboratory investigation of 11 water quality parameters was carried out using standard methods. The parameters are Na, K, EC, pH, coliform, TDS, temperature, ORP, Nitrate, PO, and SO. The results were subjected to ANOVA test and subsequently to Duncan’s Post hoc test. The result showed that 5 out of 11 parameters investigated are significant determinants of the quality namely coliform, TDS, sodium, EC and potassium. Duncan post-hoc test revealed that 9 quality parameters vary widely across the regions except pH and sodium. The implications of the findings is that wells have been sited close to dumping sites, near effluent passages and/or erosion channels, thus there is need for holistic remediation to make the water fit for human consumption in the region. Proper education is required for the rural dwellers in the region on well location and its treatment for life safety.