A Novel Approach to Contaminant Transport Modelling for Groundwater Sustainability

Drinking water is essential for sustaining households, industries, and agriculture, yet groundwater—the primary source across the Mahanadi Sub-Basin is increasingly burdened by human-driven pollution. This study employs FEFLOW to model the co-transport of nitrate and PFAS (per- and polyfluoroalkyl substances) over a ten-year period, marking the first integrated assessment of their linked behavior in the region. With a calibrated accuracy exceeding 90%, the model reveals that both contaminants share overlapping pathways influenced by aquifer slopes, hydraulic gradients, and pumping stresses. The simulations show that regions with intense agricultural activity and legacy waste disposal exhibit simultaneous rises in nitrate and PFAS levels, indicating common pollution sources and co-migration mechanisms. Purnokot emerges as the most impacted zone, where the convergence of these contaminants underscores the vulnerability of local aquifers. High nitrate concentrations in the eastern and southeastern sectors are driven by fertilizer inputs and landfill leachate, while PFAS plumes persist and extend due to their low sorption and high mobility—often mirroring nitrate distribution patterns. Together, these contaminants pose serious health risks, particularly for infants, pregnant women, and communities exposed to long-term PFAS accumulation. Although some wells may remain usable for irrigation with appropriate treatment, the study highlights the need for continuous monitoring, regulated chemical usage, and smarter water-management tools including sensors and real-time alert systems. Strengthening community engagement and adopting sustainable farming practices will be crucial for protecting public health and ensuring groundwater security in the future.