Geophysical investigation of resistivity and groundwater quality in Ogbe-Ijoh coastal area of the western Niger Delta of Nigeria

Abstract

Abstract Groundwater quality assessment is essential for groundwater resource management, especially as it concerns the health of those that consume it. Consequently, we assembled resistivity and hydrogeochemical data to assess the adverse effect of anthropogenic sources on groundwater quality in Ogbe-Ijoh, a coastal area of the western Niger Delta. Geoelectrical data showed no evidence of quality degradation as reflected by high resistivity values that ranged from 29.3 to 349.9 Ωm. Aquiclude of adequate thickness capping aquifers was uncovered in most areas assessed, with the exception of areas near the bank of the river. The delineated clay sedimentary horizon probably enhanced groundwater quality sustainability by acting as a barrier to migrating contaminants, especially from leachate and septic tanks. The physical properties of groundwater sampled indicated moderate pH, TDS and EC magnitudes, with a majority having magnitudes lesser than the requisite standards. The geochemistry of groundwater revealed cations and anions with magnitudes that are distinctively lesser than the desired ranges. Piper plot revealed two different water types: NaCl− and Ca2+ + Mg2+ + Cl− + SO4, which implied that cation exchange has a weighty effect on quality of groundwater. Overall, the hydrogeochemical results are consistent with resistivity data and revealed the efficacy of the pairs in groundwater quality assessment in the absence of lithologic information. The groundwater condition is relatively safe for consumption; nevertheless, due to health implications we recommend that pH should be increased to the required standard before drinking.

Keywords

• Groundwater
• Anthropogenic
• Niger Delta
• Ogbe-Ijoh
• Resistivity
• Cation exchange