Geoelectric Evaluation of Olushosun Landfill Site Southwest Nigeria and its Implications on Groundwater

Geoelectric resistivity technique of geophysical investigation have been used to evaluate the effect of leachate generated from Olushosun landfill on the groundwater in the area. The result shows that the first aquifer has been greatly polluted by the leachate generated from the decomposed heap of refuse materials at the landfill site. A total depth of up to 73 m has been delineated as polluted area with resistivity ranging from 16 to 361 Ωm as compared to resistivity values ranging between 2167-3714 Ωm for the unpolluted area. The results of the evaluation of the protective capacity of the overburden material within the unpolluted zone shows that the overburden material has a weak protective capacity and this may have largely been responsible for the high level of pollution observed in this area.