[A-HW17] Near Surface Investigation and Modeling for Groundwater Resources Assessment and Conservation

[AHW17-P06] "Assessment of Soil-Water quality of agricultural land surrounding MSW dumpsite and STP through geophysical and hydrogeochemical approaches"

*SHRAVANI YADAV¹, Brijesh Kumar Yadav², Maurizio Polemio³ (1.Research Scholar, Department of Hydrology, Indian Institute of Technology Roorkee, 2.Professor and Head, Department of Hydrology, Indian Institute of Technology Roorkee, 3.Senior Scientist, Research Institute for Geo-Hydrological Protection, Italian National Research Council, Bari, Italy)

Keywords:Solid Waste Mismanagement, Emerging Contaminants, Landfills, Isotopic Analysis, Surface Water and Groundwater resources

Monitoring the sources and spatiotemporal variability of pollutants in the soil and water resources is crucial for implementing effective monitoring and mitigation strategies. In the present study, we aim to characterise and identify the sources of a mixture of contaminants stemming from three major anthropogenic activities, viz., municipal solid waste (MSW) dumpsites, sewage treatment plant (STP), and intense agricultural activities. We initiated the investigation by employing geophysical methods, specifically 2D-Electrical Resistivity Tomography (ERT), to characterise the subsurface formations and to map the potential contaminated soil-water pockets. After finding the probable polluted zones, a comprehensive sampling campaign was carried out by collecting soil, surface water, and groundwater samples from various depths and locations in and around the STP and MSW dumpsite. Hydro-geochemical parameters were assessed to check the quality of soil-water resources in and around the proximity of contaminated zones. Thereafter, stable isotopes (oxygen and hydrogen) of the collected water samples were analysed to ascertain the sources of the observed pollutants. It is found that the contaminants leached into the shallow aquifers to a depth of 6m and laterally to the nearby river. Conventional pollutants are treated by STP, and the majority of contaminants from landfills and agricultural practices have a substantial effect on shallow aquifers, which in turn affects adjacent surface water resources. This study emphasizes the effective use of indirect methods such as geophysical investigations to reduce the cost of conventional sampling and monitoring of potentially contaminated sites. The use of isotopic analysis is found to be effective for the source apportionment of a cocktail of pollutants originating from these various anthropogenic activities. Overall, this integrated approach will assist stakeholders in assessing the potential sources of a mixture of contaminants and required for implementing remedial measures to complex polluted sites.