Geophysical Investigation of Aquifer Vulnerability in Gauta Buzu Area of Keffi Local Government, Nigeria

Taking into account the significance of quality groundwater for good health and quality of life, this research explored the vulnerability of the aquifer in the Gauta Buzu region of Keffi, located within the Keffi local government of Nasarawa State. The electrical resistivity method utilizing the Schlumberger electrode configuration was employed for the research to characterize the subsurface lithology and aquifer vulnerability. The research identified four (4) geological layers which comprise topsoil, weathered basement, fractured basement, and fresh basement. The weathered and fractured basements of the study area form the aquiferous zones. The depth to the weathered layer in certain locations within the study area is shallow, making the aquifer vulnerable to contamination from leachate or other chemical substances transported by erosion or runoff. The findings of the study indicated that 47% of the aquifer in the region are weakly protected, whereas 53% of the aquifer are moderately protected. The findings also revealed that shallow boreholes and wells in the study area are likely to be contaminated owing to their closeness to the surface. This observation supported the claims of groundwater contamination in the study area as documented in the literature. Given the results of this study, shallow boreholes and wells should be decommissioned in the study area, while new boreholes with substantial depths should be established in regions that possess moderate aquifer protective capacity.