The Effect of Uncontrolled Dumping of Solid Waste on Groundwater in Osun State, Nigeria

Abstract

Background: This study analyzed physical, chemical and heavy metal properties of groundwater in well water and tap water (6 each) around eight dumpsites in Osun State, Nigeria. Two Batches of Samples were collected (Batch A & B) which were respectively obtained in January and July. Heavy metals were determined using Atomic Absorption Spectrophotometer (AAS) and this led to the investigation of the impacts of open dumpsite on groundwater quality, the concentration of the examined variables where compared with World Health Organization (WHO) standard limits of drinking water. Results: The pH in water samples range from 5.2-8.6, conductivity in samples range from 100-260 µS. Nitrate in water samples range from 3.1151 mg/L-12.179 mg/L, chloride in water samples range from 15.2mg/L-151.6 mg/L. Total Hardness (TH) in water samples range from 34 mg/L-146 mg/L, lead in well water range from none detected to 0.97 mg/L and tap water range from 0.00 mg/L-1.00 mg/L. Cadmium in well water range from none detected to 0.007 mg/L and all samples in tap water range from 0.069 mg/L-0.240 mg/L. Some of these parameters were found to exceed the World Health Organization standard limit in well water and tap water. Concentrations ofheavy metals and chemicals parameters such as chromium, lead, and iron were found to be higher in groundwater in batch B tap water and batch A well water, while, total hardness and NOˉ3 were the chemical parameters with higher concentrations in most water samples. Conclusion: The result shows that some groundwater sources are unfitted for the consumption in Osun State.