Impact of Waste Dumpsite on Groundwater Quality in Ibadan, Southwestern Nigeria

摘要

Migration of leachates from a waste dump through soils and rocks may pose a threat to groundwater resources if not properly managed. This study assessed the influence of a waste dump, if any, on the groundwater quality and the extent to which it moves from the dumpsite to the surrounding area.Twelve groundwater samples were collected from seven new and five existing hand dug wells at lateral distances (0 – 500 m) away from the dumpsite. Physical parameters such as pH, total dissolved solids (TDS), and electrical conductivity (EC) were determined in-situ using a pH/ Temperature meter and Conductivity meter. Anion (Cl-, NO3-, HCO3-,and SO42-) and cation (Na+, K+, Ca2+ and Mg2+) concentrations were analyzed using Ion Chromatography and Atomic Absorption Spectrometer (AAS), respectively. Data were analyzed using descriptive statistics, graphs, regression, and correlation coefficient.The pH ranges from 5.50 to 6.60 indicating the acidic nature of the water samples. High values of TDS (149.67 - 700.27 mg/l) and EC (299.52 - 1076.21 ?m/S) were observed while respective anions (Cl-, NO3-, HCO3-,and SO42-) concentrations range from 123.95 - 288.10, 8.99 -63.50, 122.57 - 232.12, and 170.11 - 360.84 mg/l. Cations concentrations were Na+ (14.19 -38.56 mg/l), K+ (4.19 – 15.11 mg/l), Ca2+ (23.25 - 37.83 mg/l) and Mg2+ (12.11 – 22.40 mg/l). Strong correlation coefficients (r =0.90 to 0.98) were obtained from the concentration of determined parameters and distance from dumpsite and suggest anthropogenic influence on the groundwater quality. This study has shown that the Lapite dumpsite has impacted the surrounding groundwater and this has shown a significant threat to public health of the people living in the area.