Environmental assessment of old domestic dump site using 2D electrical resistivity imaging: a case study from Olubonku Dump Site in Ede, Osun State, Southwestern, Nigeria

Abstract

A direct current electrical resistivity survey using dipole–dipole profiling technique have been used to investigate the impact of Olubonku Dump Site in Ede, Osun State, Southwestern Nigeria, on the groundwater quality in the vicinity of the dump site. Ten 2D resistivity profiles with maximum length of 125 and 5 m inter-profiles spacing were laid around the perimeter of, as well as outside, the waste disposal site. The 2D resistivity structures show that the topsoil has virtually merged with the weathered layer because of overlapping relatively low resistivity values of ( 5 m for topsoil and weathered layer which were suspected to be due to high metal contents and thus leachate saturation. It was also observed that the weathered layer constitute the aquifer unit in the study area. Due to the observed relatively shallow water table of 2.1–3.5 m around the dump site, the groundwater around the dump site is suspected to have been polluted.