The Effects of Leachate on Groundwater in Ota Industrial Area Southwest, Nigeria

Abstract

Compositions of landfill leachate and groundwater pollution were studied at industrial sites landfill, which are located at Ota, Nigeria. The leachate was sampled at 5 different locations at the landfill, and at 15 and 20 m downstream of the landfill. Groundwater samples were collected from 10 different sources to study the possible impact of leachate percolation into the groundwater. The leachate and groundwater samples were collected during wet season, due to the excessive generation of leachate during this season. The objective of this work was to analyzed the groundwater pollution due to the landfill leachate. The leachate and groundwater were physically and chemically characterized. The parameters measured were pH, acidity, alkalinity, electrical conductivity (EC), total hardness (TH), chloride (Cl–),sulphate calcium hardness, heavy metals (Pb, Zn, Cd and Cu), major cations (Na, Mg, ph, and Fe). The leachate at this landfill were most likely in methanogenic phase, based on the pH value recorded (pH=6.08). The result show that the samples are contaminated, where the concentration of physicochemical parameters are below the standard acceptable levels which are required for drinking water adapted by The Nigerian Standard for Drinking water quality (NSDWQ). Therefore, detailed study of the leachate and its effect on the groundwater in the study area was recommended.

Keywords: Groundwater, leachates, conductivity, heavy metals, pollution.