Investigation of Saltwater Intrusion into Freshwater Aquifers in Some Estuary Environment in Niger Delta

Groundwater is an important source for Nigerian water balance. Therefore assessing its experimental evidence supporting saltwater intrusion is necessary before initiating developmental plans using this resources. In this research, the extent of saltwater intrusion, physiochemical properties of groundwater samples and suitability was experimented in the study areas. Geophysical and geochemical techniques were employed in a research study to investigate saltwater intrusion in freshwater aquifers in coastal areas of Delta State, Nigeria. The resistivity data from fifty Vertical Electrical Soundings (VES) in the aquifer layers revealed high water content and saline intrusion, with resistivity ranging from 0.4 to 769.9 Ωm. The hydraulic resistance values ranged from 2.877m-1 to 27.2831m-1, determining the Aquifer Vulnerability Index (AVI). The findings from the Groundwater Occurrence and Depth (GOD) index classified the study area into low and moderate vulnerability classes, with values ranging from 0.168 to 0.420. Groundwater analysis indicated elevated levels of electrical conductivity, salinity, and total dissolved solids, exceeding WHO standards. Moreover, high concentrations of chloride, sodium, and potassium confirmed saltwater intrusion.