Assessment of groundwater and soil pollution by leachate using electrical resistivity and induced polarization imaging survey, case of Tebessa municipal landfill, NE Algeria

In the last decade, the anarchical discharges have severely degraded the environment quality in Tebessa province. Due to the exudation and the percolation of leachate through the retention tanks, the Tenoukla Technical Landfill Center (TLC) is considered as the main source of the aquifer and soil pollution in the Tebessa basin. Our research intended to investigate the groundwater and soil pollution extent within and close the municipal landfill, southeast of Tebessa city, NE Algeria. For this task, we used geochemistry analysis based on atomic absorption spectrometry and geophysics prospecting based on electrical resistivity tomography (ERT) and induced polarization (IP) techniques. The chemical results showed strong soil/water contamination by high levels of mineralization (3.5 μg/g of Pb, 7.1 μg/g of Cd, 0.09 μg/g of Cu, and.05 μg/g of Zn). The IP and ERT image indicated large zones of decomposed waste bodies saturated with highly conducting leachate (resistivity’s value varies from 3 to 10 Ω m). This high mineralization concentration in the vadose zone is due to the leakage of the leachate, through the permeable Cenomanian marly limestone. Cd, Pb, Cu, Zn, Fe, and Mg element concentration in sediments caused the degradation of water quality. These results confirm a general trend of pollution towards the downstream area. Soil exchangeable bases were higher in the vadose zone compared to the saturated one. Our study gives a good example of the potential of the ERT/IP method for the hydrogeological investigation and for the pollution characterization especially in landfill sites. These tools could help decision-makers in our study area or in a similar environment for monitoring environmental parameters, reduce the risk, and avoid critical pollution situations caused by the leachate resulting from landfills. We highly recommended initiating a depollution plan for a both soil and water.