Impact of Solid Waste Dumpsite on Groundwater Quality in the Neighbouring Communities

Leachate seepages into groundwater aquifer from solid waste dumpsites is likely to release toxic pollutants in groundwater which are hazardous to human health and local ecosystem. A study was conducted on the Physico-chemical parameters of dumpsite leachate and surrounding groundwater from Awotan Solid Waste Dumpsite, in Ibadan, Oyo State. The study was aimed at assessing the impact of the leachate from the dumpsite. The physicochemical analyses of the water samples were carried by standard analytical methods. The results obtained were compared with the WHO (World Health Organization) permissible limit of those parameters in drinking water. The Physico-chemical values obtained for the dumpsite leachate were generally higher than those of groundwater samples, suggesting that a source of contamination could be from the dumpsite leachate. The pH of groundwater samples ranged between 5.03 to 6.94, indicating that the groundwater was acidic. Results of Physico-chemical parameters of dumpsite leachate for Cl-, NO3, TH, Alk, BOD, COD exceeded the WHO limits for drinking water. The BOD and COD of dumpsite leachate and groundwater samples exceeded the WHO limits and hence not safe for drinking. The concentration of Cl- and TH in the groundwater closer to the dumpsite were higher than WHO permissible limits for drinking water. Also, concentrations of the analyzed parameters decreased with increasing distance from the dumpsite, thus implicating leachate seepage from the dumpsite into the groundwater. It is therefore recommended that dumpsites be located away from the human settlements to avoid drinking water contamination and local ecosystem & biodiversity degradation.