Hydro-Geochemical Studies of Groundwater Around Oke-Ebo and Within Ajayi Crowther University Campus, Oyo Town, Southwestern Nigeria

Major ionic chemical composition and physico-chemical parameters of eighteen (18) groundwater samples within Ajayi Crowther university (ACU) and Oke-Ebo area of Oyo town, southwestern Nigeria were analysed for hydro-geochemical facies characterisation. The pH ranges from 6.2 to 7.5 and the total dissolved solids (TDS) was between 240 and 1570 mg/L. The total dissolved solids were found higher in samples within the ACU premises compared to those in other areas. The spread of major ions concentration in mg/L are Ca2+ 16 – 62, Mg2+ 7.5 – 23.3, Na+ 4.13 – 13.1; K+ 2.12 – 7.18 and for anions; HCO3- 50 – 180, SO42-, 10 – 48, NO3-, 1.36 – 8.04; and Cl- 18.71 – 65.58. From the average concentrations, the relative abundance of the cations is in the order of Ca2+>Mg2+>Na+>K+ while for anion, it is HCO3- >Cl- >SO42- > NO3-. For hydro geochemical facie classification using piper plot, the groundwater is predominantly the Ca-HCO3 water type.