Deborah O. Olorode and Ayobami O. Alao
This research examines the effects of solid waste on the quality of underground water in Solous III dumpsite, Igando, Alimosho Local Government area of Lagos, Nigeria. The study was born out of the unregulated manner in which common dumpsites are operated and the way in which both domestic and industrial wastes are deposited in the streets, river courses, buried or burnt and discarded in refuse heaps. Solid wastes commonly generated in Lagos includes papers and cartons, food remnants, glass and bottles, plastic and polythene, tin and metals, ashes and dust, textile and rags, aluminum and other minerals. The geo-electrical methods used in the survey are Vertical Electrical Sounding and Very Low Frequency techniques. Measurements of eleven vertical electrical soundings (VES) were conducted using the Schlumberger configuration and eighteen profiles using the very low frequency (VLF) method. The resistivity method was carried out with a view to characterize different subsurface geological units and to provide the engineering or environmental geophysical characterization of the study area. The VES data were subjected to an iteration software (WIN RESIST) which showed that the area is composed of top soil, clay, sandy clay and sand. The Very Low Frequency data was also subjected to iteration software (SURFER 8) which gave the imaging of the lateral variation in resistivity. Based on the interpretation of the two methods, interested layer under the geo-electric section is VES1-11 which signifies a probable aquifer’s zone with resistivity range between 206.2 Ωm and 406.6 Ωm, and thickness from 3.0 m to 13.0 m. The graph of the very low frequency method also shows that areas close to the dumpsite and areas of about 300m away from the dumpsite had been greatly contaminated. [Profiles 1 to 18]