Evaluation of saltwater intrusion in Groundwater at Bakana, Rivers State

Saltwater intrusion is a significant concern for coastal regions like Bakana, Rivers State, Nigeria, wherefreshwater resources are critical for the local population. This study evaluates saltwater intrusion into thegroundwater system using Electrical Resistivity (ER) surveys at St. Andrew's Church, Bakana. The researchaimed to delineate the freshwater-saltwater interface, identify freshwater aquifers, and assess potentialcontamination zones. Using advanced Electric Resistivity instruments such as the ADMT Digital Terrameter,data were collected along multiple survey lines and analyzed to create resistivity contour maps and 2Dtomograms. The results revealed the presence of multiple freshwater-bearing formations at varying depths,ranging from 13 to 200 meters, with distinct layers of clay and silty clay overlying aquifer formations.Additionally, areas of potential saltwater intrusion and hydrocarbon contamination were identified,particularly in regions where resistivity values were lower. These findings provide critical insights forsustainable groundwater management in Bakana, offering a basis for informed decision-making in boreholedrilling and the protection of freshwater resources. The study underscores the utility of electric resistivitysurveys in coastal hydrogeological investigations, particularly in identifying and mitigating the impacts ofsaltwater intrusion.