Abstract

      Electrical resistivity method was used to investigate the effect of leechate contamination of groundwater at Sotubo solid waste dumpsite. Both Vertical Electrical Sounding (VES) and Constant Separation Traverse (CST) technique were carried out using Schlumberger and Wenner electrode configuration, the estimated apparent resistivities (ρ) were interpreted using partial curve matching technique and computer iteration. The inferred lithology includes topsoil, sandy layer, limestone and sandy-clay with resistivity of 90, 421.5, 907.8, 143.0 Ωm and thickness of 1, ~3.8, ~29.0 m and infinity, respectively. The pseudosection revealed the leechate had a thickness of 19.8 to 25.0 m with ρ of 0.17 to 32.5 Ωm in the NW part of profile 1. In contrast, apparent resistivity of the leechate is less than 5.95 Ωm in profile 2. The leechate has infiltrated potential aquifers such as the sandstone layer. Aquiferous layer exceeding the depth of the contaminated zone can be drilled with screened borehole in order to avert groundwater pollution.

Key words: Leechate, contamination, ERI, Sotubo, groundwater