Hydrogeochemical assessment of dumpsite leachate on groundwater quality in Igbatoro, Akure-North, Ondo State, Nigeria

Groundwater is a vital resource for domestic and industrial activities in Akure, Nigeria, yet it is increasingly threatened by uncontrolled urbanization and improper waste disposal. This study investigates the hydrogeochemical impact of leachate from the Igbatoro dumpsite on nearby water resources, addressing the critical problem of unlined landfills releasing organic and inorganic pollutants into local aquifers. The general objective was to evaluate the extent of physicochemical and bacteriological contamination in the surrounding groundwater and surface water. Using a grid sampling methodology, five samples, four from hand-dug wells and one from a stream were collected at radial distances between 197 m and 975 m from the site. Samples were analyzed using standard APHA methods and compared against WHO and Nigerian Standard for Drinking Water Quality (NSDWQ) guidelines. Major findings revealed slightly acidic groundwater (pH 5.65–6.80) and elevated concentrations of Total Dissolved Solids (901 mg/L) and Electrical Conductivity (1801 µS/cm) in proximal wells. Most alarmingly, bacteriological analysis identified harmful pathogens, including faecal coliforms reaching 68 cfu/100mL, far exceeding the 0 cfu/100mL limit. Statistical evaluations, including Principal Component Analysis, confirmed leachate infiltration as the primary driver of ionic enrichment. The study concludes that the Igbatoro dumpsite poses a severe threat to public health. Recommendations include replacing the open dump with an engineered sanitary landfill and enforcing a 500-meter protective radius for future borehole development.