Investigation of groundwater contamination from leachate migration: a case study of Bowen University dumpsite, Nigeria

Abstract

A microstudy of soil physical properties in combination with geoelectric delineation were adopted for the evaluation of groundwater contamination prospect from leachate migration at Bowen University dumpsite location. Samples of soil were collected from five different locations, with five locations within the dumpsite and one control sample which is 200 m far away from the dumpsite locations. A core sampler which is attached to the soil auger is used to obtain each sample within 60 cm depth. Each sample is collected into a sample bag and properly labeled for laboratory analysis. Schlumberger electrode configuration was employed for the survey spread to delineate total of four (4) Vertical electrical sounding (VES) points with electrode spacing varying 60 to 100 m. This was done to obtain resistivity, thickness and depth within the dumpsite location. The results of the average value of the soil properties between the control and the dumpsite are compared such that the soil properties for control site reveal a bulk density (BD) of 1.45 g/cm3, particle density (PD) of 2.63 g/cm3 and porosity (PO) of 44.90%, respectively. Whereas, the mean soil properties of the dumpsite show that BD is 1.35 g/cm3, PD is 2.93 g/cm3, and PO is 54.07%, respectively. This signifies that the control location has high BD, low PD and low PO, while the dumpsite reveals an inverse of the control results. Also, the results from the interpreted VES data reveal the prospect of migration of contaminants from the topsoil to the alluvium, which could further percolate to the aquifer with time. It could be concluded that groundwater contamination is feasible within the study area, since an alluvium and porous soils could permit leachate migration to the aquifer.