Effects of dumpsite leachate plumes on surface and groundwater and the possible public health risks

Abstract

Groundwater is a sacred natural resource and its security is not negotiable. However, the high level of environmental indiscipline and the shambled state of waste management in Nigeria poses a significant risk to environmental health. In this study, we employed subsurface resistivity and hydrochemical data along with diagnostic surveyed questionnaires (DSQ) and physical surveys, to critically assess the impacts of dumpsites on the environmental matrices (soil, surface and groundwater) and the possible public health risk associated with it. The resistivity data indicates that the overburdened soil layer overlaying the groundwater systems is heavily burdened, exhibiting consistently low values ranging from 4.1Ωm to 131Ωm. The low values were attributed to the presence of high content of heavy metals (HMs) due to leachate plume infiltration, which significantly impacted the groundwater and the upper layer of the Earth's crust, causing a land cave-in, consequently slope and structural failures. The hydrochemical data indicate a high content of TDS (400–1612) mg/l, BOD (371–611) mg/l, COD (697–1117) mg/l and HMs (0.012–1.787) mg/l, which indicates high organic potency deposited in the leachate contaminants. The electrical conductivity (EC) values vary between 0.211 and 1.502 mg/l as against WHO permissible limits for potable drinking water. The high values of EC reflect a high level of dissolved materials, affirming the conductive nature of the dumpsites revealed by the resistivity data. Natural waste decomposition and burning are prime sources of pollutants with adverse effects on the environmental matrices and public health. The leachate plumes seeping the ground could metamorphose into a power force annihilating the load-bearing capacity of the topsoil, resulting in slope and structural failures. This study will aid policymakers in making informed decisions and implementing targeted strategies to mitigate dumpsite's adverse effects.