Geoelectric and Electrochemical Investigation of Piggery Waste Deposits and Their Environmental Impact at Bouesti Farm, Ikere Ekiti, Ekiti State, Southwestern, Nigeria

Abstract

This study investigates groundwater contamination resulting from untreated piggery waste disposal at BOUESTI Farm, Ikere-Ekiti, Southwestern Nigeria. The discharge of effluent into unlined pits promotes leachate generation and rapid infiltration into underlying aquifers, particularly within a hydrogeological setting characterized by intense tropical rainfall and permeable lateritic soils. Such conditions significantly increase aquifer vulnerability and threaten local potable water supplies.
An integrated approach combining Electrical Resistivity Tomography (ERT), Vertical Electrical Sounding (VES), and hydrochemical analysis was employed to delineate subsurface contamination and assess groundwater quality. The geophysical surveys identified extensive low-resistivity zones (<50 Ωm) extending laterally and vertically from the waste disposal area, indicative of conductive leachate migration pathways. Hydrochemical analyses of water samples from wells, boreholes, and waste pits revealed elevated Electrical Conductivity (EC), Total Dissolved Solids (TDS), and nitrate (NO₃⁻) concentrations, with several values exceeding World Health Organization (WHO) permissible limits for drinking water. The detection of faecal coliform bacteria further confirmed significant microbial contamination.
The integrated findings demonstrate the presence of an active leachate plume and confirm that the groundwater system is both chemically and microbiologically compromised, rendering it unsuitable for human consumption. The study highlights the urgent need for engineered waste containment systems, leachate treatment infrastructure, and continuous groundwater monitoring to mitigate environmental degradation and protect public health.