Abstract

2-D resistivity imaging and physicochemical analysis were used to investigate the intrusion of leachates on groundwater quality around a dumpsite in Tarauni Local Government Area of Kano State, Nigeria. Four (4) imaging traverse lines were established and Wenner configuration was adopted using an electrode spacing from 5.0, 10.0, 15.0 to 60.0 m. Data collected from the imaging were inverted using AGI EarthImager 2D software and the results obtained were used to construct the Geologic model section using Surfer 9.0 software. Fifteen (15) water samples were collected for the physicochemical analysis from in and around the study area. The results indicated the presence and the range of the following parameters: pH (6.86-8.1), electrical conductivity (E.C) (305 -1239 μS/cm), total dissolved solid (TDS) (215 – 747 mg/L), nitrite (NO2-) (0.18 - 0.59 mg/L), phosphate (PO4) (2.4 - 7.16 mg/L), cadmium (Cd) (0.003 - 0.3 mg/L), chromium (Cr) (0.020 - 0.79 mg/L), copper (Cu) (0.125 - 02.273 mg/L) and iron (Fe3+) (0.10 - 0.25 mg/L). All the parameters analysed were found to be above permissible limit in the control sample; this shows that the dumpsite was the source of the groundwater contamination. Traverse 3 and 4 were the mostly affected. In Traverse 3 the contamination reached a depth of about 17.1 m between 160 and 175 m along the profile while in Traverse 4 it reached a depth of about 26 m which extends from 5 to 85 m along the profile. Groundwater samples in the study area were found to be inadmissible for human consumption when results were compared with specification from WHO (2008) and NSDQW (2007) standard. Both results of the resistivity imaging and physicochemical analysis indicated the presence of contamination in the subsurface water.

Key words Dumpsite, resistivity imaging, leachate, groundwater contamination, physicochemical analysis.