IMPACT OF WASTE DISPOSAL SITE ON GROUNDWATER QUALITY AT RAFIN TOFA SOLID WASTE DUMPSIT

Abstract

A massive solid waste dumpsite at the outskirt of Minna metropolis was investigated using 2D electrical resistivity imaging (ERI), with the aims of determining the impact of the dumpsite on groundwater quality. By visual observation of solid waste dumpsite, it is found that it consists of various constituents such as paper, organic matter, metals, glass, ceramics, plastics, textiles, dirt, and wood among others. Resistivity data were collected from parallel survey profile lines using a Wenner-Alpha array configuration. Inversion of the data was carried out using 2D regularized least-squares optimization methods with robust (L1-norm) model constraints. Potential zone of leachate infiltration into the subsurface from the dumpsite was identified from the electrical imaging. A synthetic resistivity inverse model was used to discuss and validate the field results. The 2D ERI sections of the model resolve clearly the subsurface lithological variations. Interpretation of the field data showed that 2D ERI technique was effective in delineating groundwater contaminated zones. The vertical and horizontal sensitivity of the 2D Wenner-Alpha array for sub- surface resistivity variations made it possible to determine the position and extent of leachate infiltration into groundwater. The current work demonstrates the usefulness of the ERI technique as a complementary tool for environmental site investigation