Abstract

The relevance of geophysical investigation and biochemical inputs in groundwater exploration and development cannot in anyway be ignored or underrated in any society. Groundwater investigation and water quality status of existing boreholes and hand-dug wells in Ewekoro community, South-West Nigeria was investigated. Qualitative assessment was determined using Frequency Domain Electromagnetic method (FDEM) using GEONICS EM-34; The FDEM detected the shallow conductive zones connected with the local water circulations with recorded true conductivity which ranges from 45.84 mmho/m in the first layer to 173.39 mmho/m in the second layer. Quantitative assessment was also achieved by the integration of biogeochemical analyses of the water samples collected from 25 boreholes and 25 hand-dug wells at various sampled points across the residential vicinity of the study area. As part of the quantitative evaluation, physical parameters (pH, TDS, DO, BOD salinity, total hardness, turbidity, electrical conductivity EC and temperature) of the water samples were also determined. Standard Analytical Methods were employed for all analyses and the results were compared with both National and International water quality standards including World Health Organisation (WHO), and National Environmental Standard Regulation Agency (NESREA). Most quality determinants in the sampled water are within the set guidelines except DO, BOD, ALK, Cl-, HCO3-, MgCO3-, Cd2+, Zn2+ and Fe3+. The overall ionic dominance pattern for the borehole and hand-dug well follows the same trend; K+ >Na2+ > Ca2+ >Fe3+ > Mn2+ > Cd2+ and Cl− > PO43->NO3- >NO2-. The hygienic condition of the water bodies was found to be poor. The results therefore imply that water bodies in Ewekoro are polluted and pose potential risk to humans.