IMPACT OF LEACHATES ON THE QUALITY OF GROUNDWATER IN SHAGAMU SOUTHWESTERN, NIGERIA IN GROUNDWATER – SOME URBAN CITIES OF SOUTHWESTERN, NIGERIA

The overwhelming environmental significance of solid waste has attracted a lot of attention because of its leaching into groundwater through waste deposit. The study determines impact of leachate from a landfill site on the quality of groundwater sources in Shagamu, Southwestern, Nigeria. Twelve groundwater samples, (hand dug wells (7) and boreholes (5)) were analyzed for their major ionic components. Groundwater qualities for cation were determined at Acme Laboratories, Canada and anion was determined at the University of Ibadan, Nigeria. Mean concentration of pH (5.89) was found to be outside the WHO 2004 and USEPA 2001 permissible limits, and was due to the effect of leachate on the groundwater. Total dissolved solid, Electrical conductivity and Alkalinity were found to be within the permissible limits. Mean concentration of cations and anions for all the samples were -also found to be within the permissible limits with the exception of Mn (0.50 mg/L), Cl (83.33 mg/L), -and NO (26.44 mg/L) respectively which could be as a result of abattoir found around the dumpsite. 3 Leachate has had significant impact on groundwater quality. Groundwater quality improves with increase in depth and distance of the well and boreholes from the pollution source (landfill). The present study demands for proper management of waste and suggests some remedial measures to reduce future groundwater contamination via leachate percolation,