Groundwater Quality Assessment of a Coastal Aquifer in Niger Delta Using Geo-electrical Techniques

The geo-electrical techniques involving the VES and 2-D resistivity imaging was used in assessing the groundwater quality of a coastal aquifer in Ogu-Bolo Local Government Area of Rivers State. This study used two Vertical Electrical Sounding data and three horizontal profiling data obtained using ABEM SAS 300B Terrameter. A computer modeling was used in processing the Data and partial curve matching was employed in the interpretation of the VES data. Five geoelectric layers of varying thicknesses, depth and resistivities were delineated. The fourth layer is where the best aquifer ranged from 41.70m to 42.90m at the various VES stations. The mean aquifer thickness, depth and resistivity value were calculated to be 23.74m, 42.30m and resistivity value of 3033.50 Ωm. The results of the interpretation of the two VES stations and the 2-D data have offered the opportunity of knowing the possible aquiferious zone within the study area. The results reveal that beyond the depth of 15.00m an aquifer system devoid of salt water intrusion will be possible.