Jegede, S. I., Osazuwa, I. B., Ujuanbi, O. and Chiemeke, C. C.
2D Electrical Resistivity imaging survey was carried out at the Old Cemetery and Tsamiya waste disposal sites in Zaria metropolis over a period of ten months with a view to monitoring the migration of leachate plumes within the subsurface. The Abem Lund Imaging system with Terrameter SAS 4000 was used for the data acquisition and processing while the Res2dinv software was used for the interpretations. The result revealed a leachate plume migration rate of 2.50 m/month and 2.05 m/month, in the lateral direction as well as 0.67 m/month and 0.53 m/month in the vertical direction, in the Old Cemetery and Tsamiya dumpsites, respectively. The rate of migration was found to depend on the compaction of the soil texture, the presence of loose soil, fractures, depressions, undulations and dipping topography of the subsurface. The rate of migration was higher in the Old cemetery dumpsite than in the Tsamya dumpsite. The rate of migration in the horizontal direction was higher than that in the vertical direction in both sites by a very significant margin of 1.83 m/month and 1.42 m/month in the Old cemetery and Tsamya dumpsites respectively. The vertical motion was impeded by the presence of clay as revealed by the inverted resistivity models with resistivity values in the range of 46.4 to 100 Wm and 82.0 to 100 Wm in the Old cemetery and Tsamya dumpsites respectively.
