ABSTRACT When solid waste is disposed of at landfills, it undergoes a combination of physical, chemical and microbial processes. These processes help to transform the waste into various water-soluble compounds termed (leachate) and transfer the pollutants from the refuse to the percolating water, leading to contamination of surrounding groundwater and surface water. Characterisations of the leachate originating from the Isale-Ijagba and Oke-Diya dumpsites (situated in Sagamu, Ogun State, Nig...