ASSESSING GROUNDWATER CONTAMINATION FROM LANDFILL LEACHATE: INTEGRATION OF ELECTRICAL RESISTIVITY TOMOGRAPHY (ERT) WITH PHYSIOCHEMICAL WATER QUALITY ANALYSIS IN SALIYAR LANDFILL, ROORKEE INDIA

Abstract

Groundwater contamination might result from contaminants migrating in either vertical or horizontal directions, influenced by geogenic and anthropogenic factors in the surrounding environment. Solid waste disposal is one of the most significant sources of groundwater pollution. Landfill leachate results from rainwater infiltrating through waste in dumpsites, which further percolates the soil layers to reach the lower soil layers. Conducting non-invasive, cost-effective, and environmentally friendly investigations using Electrical Resistivity Tomography (ERT) around the landfill helps map and identify the extent of the leachate plumes and assess groundwater contaminants. In the present study, an analysis of groundwater quality near a landfill site using ERT has been conducted. Electrical resistivity (ER) surveys of the landfill site were carried out in different directions to locate contaminant plumes and transport behaviors from November 2023 to March 2024. Further, the groundwater samples from nearby boreholes were collected, and physicochemical analyses were performed to determine the chemical composition of the groundwater near the landfill. The 2D electrical resistivity tomography results revealed that leachate had migrated both in spatial and vertical directions, contaminating the shallow aquifer. The ERT profiles demonstrated low resistivity values (<10Ωm), highlighting the extent of infiltration of the leachate. The ERT findings were further validated by the elevated concentrations of EC, TDS, Cd, Pb, Mn, and Al in the groundwater samples from operational wells. These analyses indicate that groundwater has been contaminated by landfill leachate infiltration. Overall, the study discusses the extent of leachate infiltration into the aquifer near the Saliyar landfill areas.