GEOPHYSICAL ASSESSMENT OF GROUNDWATER CONTAMINATIONS FROM LEACHATE INTRUSION IN AMOYO DUMPSITE

Abstract

The work aims to map the extent of leachate intrusion in near-surface rocks around a reclaimed dumpsite (40 years old) in Amoyo town. Sixteen very low-frequency electromagnetic (VLF - EM) profiles were distributed in the four cardinal directions around the site. Twenty-nine (29) points were sounded, using Schlumberger approach, at all identified VLF anomalous points. The analyzed VLF-EM data revealed the presence of conductive pollutants (leachate plumes) at the subsurface. The geo-electric sections generated from the processed VES data supported the VLF-EM results. It is concluded that (i) leachate is still present in the rock formation of the reclaimed dumpsite several years after the abandonment and excavation of the waste materials (ii) the shallow aquifer is at risk of contamination (iii) the low resistivity of the basement rocks signified presence of leachates.