Characterization of Groundwater Quality from Surface Geoelectrics: The Case of the Sombreiro – Warri Deltaic Plain Aquifer, Western Niger Delta, Nigeria

Abstract

The vertical and aerial distribution of total dissolved solids (TDS) in groundwater from the predominantly unconfined aquifer in the Sombreiro - Warri Deltaic Plain deposits at Orerokpe in the western Niger Delta have been inferred from geoelectric survey data. Results reveal a dominant trend of decreasing TDS with depth. Specifically, TDS values at 5 m are in the range of 11.2 ppm to 1914.9 ppm (mean value of 451.6 ppm) and thus indicative of the fact that the quality of water at this depth may have been compromised. However at 20m below ground level, TDS are in the range of 44.1 ppm to 151.7 ppm (mean value of 85.7 ppm) which is predominantly below 500 ppm and thus well within the range recommended by the Standards Organization of Nigeria and the USEPA for drinking water supply. The inferred TDS from geoelectric data are in agreement with results obtained from chemical analyses of groundwater samples obtained in previous studies in the area and thus confirm that geoelectric surveys can be helpful in evaluating total dissolved solids (TDS) in the absence of water samples.

Keywords: Resistivity, Total dissolved solids, Aquifer, Contaminants, Maximum contamination limit.