The Impact Assessment of Oil Spillage and Trace Metal Assessment on Groundwater in Baruwa, Lagos Southwest and Nigeria

Electrical resistivity surveys and trace metal assessment of groundwater were carried out in Baruwa area of Alimosho Local Government Area, Lagos-State, Nigeria. The study is aimed at determining the extent of oil spill impact on the groundwater quality of the area. The geophysical acquisition technique involved 2-D resistivity survey using the Wenner array configuration with multi-electrode system. The resistivity data from the traverses were used to generate a 2-D resistivity structure using the DIPRO software. The polluted zone was delineated as an area of high resisitivities (350 > Wm) within the study area. The concentration of all other trace metals investigated in groundwater, except for the zinc were higher than the WHO allowable limits in drinking water. The enrichment factors of Pb, Cd, Ni, Fe and Zn found present in top soil were all less than unit ( < 1.0 ) and pollution load index (0.06) showed that the impact on groundwater is still at contamination level and top soil in study area is in good state. The 2-D resistivity structure shows the subsurface layers up to a depth of 5m indicating the areas of high resistivity (probably due to oil spillage), which might have affected the agricultural produce and groundwater development in the study area.