Groundwater Quality Assessment and Contour Mapping Around Ghazipur Landfill, Delhi, India

Landfills are of prime importance in developing countries for waste management. However, in case of non-engineered landfills, leachate percolating down through its layers pose an ultimate pollution threat to both ground and surface water resources. The present study focuses on the assessment of groundwater quality in the vicinity of a landfill to examine the potential impact of the landfill on the groundwater. Ghazipur landfill is selected for the study, and thereby, ten sites have been examined for the water quality parameters. Groundwater quality analysis revealed elevated concentrations of TDS (455–1160 mg/L), Alkalinity (206–600 mg/L), Hardness (180–520 mg/L), Chloride (40–365 mg/L), BOD (2.5–10 mg/L), COD (26–48 mg/L), Zn (0.4–1 mg/L), Cadmium (0.01–0.05 mg/L), and Lead (0.04–0.07 mg/L). All the parameters (except pH) at most of the locations were found to exceed the Indian standard values for drinking water. Statistical analysis further highlighted strong inter-parameter relationships (Pearson coefficient > 0.90) and good R² values (0.66–0.97) for most of the parameters, suggesting a common source of origin and distance-based dilution of contamination. Sampling location S6 in the North was found to be the most contaminated location, and location S4 in the East was the least contaminated location. The major finding of the study indicates that heavy metals—lead and cadmium metals lie significantly above standard levels, which need to be addressed on a priority basis, due to their substantial health risks. Contour maps around the landfill suggested that the groundwater in areas immediately next to the landfill is not suitable for drinking; however, zone suitability for drinking increased with an increase in distance from the landfill.