Groundwater quality assessment and characterization of shallow basement aquifers in parts of ado ekiti metropolis, Southwestern Nigeria

Groundwater samples were collected randomly from hand-dug wells in parts of Ado Ekiti metropolis and were subjected to its quality assessment and characterization. Physicochemical and bacteriological analyses were carried out following standard methods (APHA 2012). Hydrochemistry of the present study revealed relative mean concentration of the cations in the order: Na + > Mg 2+ > Ca 2+ > K + , and that of the anions as Cl − > HCO 3 − > SO 4 2− > NO 3 − , respectively. The microbial test shows that E. coli tested positive in all the samples and their colonies are classified dominantly as satisfactory pollutant free state. Pollution index of groundwater results revealed an insignificant state of pollution of the groundwater. Deduction from the Pipers, Gibbs plots and chloro-alkaline indices results revealed the imprints of natural weathering, ion-exchange processes and anthropogenic activities influencing the groundwater quality. Factor analysis result also confirms the prevailing activities of natural geological forces and municipal contaminations acting on the groundwater. The hydrochemical processes coupled with the permeable nature of the aquifer media and high precipitation will influence groundwater flow and ultimately pose pollution risk to the aquifers and eventually the populace of these areas in years to come.