GEOPHYSICAL AND GEOCHEMICAL CHARACTERIZATION OF OIL SPILL SITES-A CASE STUDY OF FOROPA AND EKENI, BAYELSA STATE, NIGERIA

This study investigates the extent of contamination and hydrocarbon distribution in oil spill sites in Foropa and Ekeni, Bayelsa State, Nigeria, using an integrated geophysical and geochemical approach. Geophysical methods, including Electrical Resistivity Imaging (ERI) and Ground Penetrating Radar (GPR), were employed to delineate subsurface features and contamination plumes. ERI profiles captured variations in resistivity across depths, identifying hydrocarbon-rich zones, while GPR provided high-resolution images of shallow subsurface anomalies, such as buried hydrocarbon pools and fractured zones. Geochemical analyses focused on soil and water samples collected at varying depths (0–50 cm) and locations, quantifying Total Petroleum Hydrocarbons (TPH), heavy metals (e.g., lead, cadmium, chromium), pH, and salinity. Laboratory analyses adhered to ASTM and EPA guidelines, ensuring data reliability. The findings revealed significant contamination, with low resistivity values (6–8.7 ohm-meters) identifying hydrocarbon-rich layers between 5–15 meters. Geochemical data showed elevated TPH levels (4,800–5,200 mg/kg) and heavy metal concentrations exceeding World Health Organization (WHO) limits. GIS mapping highlighted contamination hotspots near spill points, correlating spatially with hydrocarbon accumulation and geophysical anomalies. This research underscores the value of integrating geophysical and geochemical methods with GIS for accurate environmental assessment and remediation planning. The results provide actionable insights into managing oil spill impacts in the Niger Delta region, emphasizing the need for urgent intervention and sustainable environmental practices.