Assessment of the effect of Leachate on groundwater quality around Lapite dumpsite in Ibadan, Southwestern Nigeria

Abstract

This study assessed the effect of leachate generated by Lapite dumpsite on groundwater quality of the sites around it. Fourteen (14) groundwater and one (1) leachate samples were collected and analysed for cations, anions, heavy metals and water physical parameters. The result of this study indicated that concentrations; cations (Na+, K+, Mg2+, and Ca2+), anions (NO3 -, Cl-, HCO3 -, and SO4 2-) and physical parameters (pH, temperature (o C), total dissolved solid (mg/l) and electrical conductivity (us/cm) measured for all the water samples outside the boundary of the dumpsite fall within the range provided by WHO (2003) for drinking water. Reverse is the case for the leachate, stream and well water samples, collected at the entrance of the site. Heavy metals present except chromium and cadmium did not fall within the range provided by WHO (2004). This may be attributed to the effect of leachate from the dumpsite. This suggested that the groundwater around the site is still safe for human consumption and therefore suitable for engineering constructions. Although the heavy metals such as lead and iron present in the water should be treated. The water in the well at the entrance of the site is not safe for drinking and therefore all the groundwater within the compound of the site might have been contaminated and hence not safe for human consumption and engineering constructions.