SURVEY OF GROUNDWATER CONTAMINATION LEVEL IN SELECTED DUMPSITES IN KADUNA, NORTHWEST NIGERIA, USING RESISTIVITY AND S EIS MIC TOMOGRAPHY METHODS

Abstract

Survey of groundwater contamination level in selected dump sites of Kaduna, Nigeria have been evaluated using integration of resistivity and seismic tomography methods. Schlumberger array was used to acquire one hundred and forty-four VES stations and were interpreted using software — Win Resist. Two hundred and ninety four seismic stations were shot along fifteen profiles with geophone separation of 3m and an offset distance of 1.5m along each profile. A 24 channel ABEM seismograph was used in recording the data and was interpreted using ReflexW software. The VES results obtained reveal that the thickness and resistivity values for various layers are given as; top soil (0.6 to 3.2 m and 13.6 to 128.4 SZ -m), weathered layer (2.3 to 54.9 Q-m and 15.5 to 554.0 Q-m), fractured basement (5.7 to 27.4 m and 8.0 to 447.052-m), and fresh basement (165.5 to 2328.1 52-m). The seismic tomography results reveal layer velocity ranges: 250 to 1200 nits topsoil, 900 to 2600 m/s weathered laye; and 1400 to 1800 mrs fractured basement. The rate of leachate contamination at the area is calculated to be 0.5 m per year, while the depth of contaminations ranges from 6.7 to 15.9 m in the area. The study suggests that Millennium dumpsites truly contaminated the groundwater sources, unlike the NDA dumpsites which is minimal