Integrated Geophysical and Hydrochemical Assessment of Groundwater in Alor and Its Environs, Southeastern Nigeria

Abstract

This study presents an integrated geophysical, and hydrochemical assessment of groundwater in Alor and its environs in Idemili South Local Government Area of Anambra State, Nigeria. The research utilized geological mapping, vertical electrical sounding (VES), and hydrochemical analyses to characterize the subsurface lithologies, aquifer systems, and groundwater quality. Geological mapping revealed that the area is predominantly underlain by the Nanka Formation, consisting mainly of poorly consolidated sands, claystone, siltstone, and ironstone beds. Geophysical investigations delineated five to six geo-electric layers, with aquiferous zones identified at depths of 117-155 m and resistivity values ranging from 1,213 to 5,442 Ωm. Hydrochemical results indicate that surface waters are slightly acidic, elevated biochemical oxygen demand (BOD), Heavy metal (Hg, Cd, Ar, and Pb) concentrations are high, and E. Coli are found in all the samples, rendering them unsuitable for drinking without treatment. The findings collectively reveal the presence of unconfined aquifers with favourable hydrogeological conditions yet poor water quality, highlighting the need for proper treatment before domestic use. This integrated assessment contributes to improved groundwater development, sustainable water resource management, and enhanced community wellbeing.