A Geophysical Investigation of a Solid Waste Landfill Using Vertical Electrical Sounding Method in Aluu Community, Rivers State, Nigeria

Abstract

Vertical electrical sounding was conducted at a solid waste landfill in Aluu community for a hydro-geophysical assessment of the contamination of soil and groundwater. The ABEM Terrameter employing the Schlumberger array was used for direct current resistivity model using a maximum electrode separation of AB/2 of 100 m. The acquired data was processed and interpreted using IPI2win software to produce ‘A’ type curve as well as resistivity and the thickness of the layers with depth. From the result, five layers were obtained and the first layer has a resistivity of 34.7 Ωm with a thickness of 1.84 m and was interpreted as the top soil. Underlying the first layer is a second layer with a resistivity value of 114 Ωm with a depth of 4.29 m and thickness of 2.45 m was interpreted as lateritic sand.  The third layer with resistivity value of 215 Ωm with depth of 11.1 m and thickness of 6.83 m was interpreted as sand. There is a fourth layer with resistivity value of 605.0 Ωm with depth of 41.8 m and thickness of 30.6 m was interpreted as coarse sand and this could be the probable aquiferous zone. The fifth layer with resistivity value of 165 Ωm with undetermined depth and thickness was interpreted as clay.  The results revealed that the surrounding soil and groundwater close to the landfill have actually been contaminated to depth exceeding 11.1m which is well within the groundwater aquifer system in the area.