Feasibility of Groundwater Extraction in Nitrate-Impacted Groundwater Source in Serbia: Hydrodynamic Modeling and Nitrate Tracing

Abstract

Groundwater, essential for supplying drinking water to half of the global population and supporting nearly half of all irrigation needs, faces significant contamination risks. These risks pose serious threats to human health and ecosystem integrity, driven by increasing pressures from both concentrated and diffuse pollution sources, as well as from growing exploitation. The presented research was conducted with the dual objectives of identifying sources of nitrate contamination (up to 128.1 mg/L) in an oxic groundwater source (Perkićevo, Serbia) and proposing an optimal extraction regimen to ensure a sufficient supply of potable water. Correlations between chemical elements’ concentrations and principal component analysis (PCA) indicated a significant relationship between anthropogenic impact indicators (NO3−, Na+, B, Cl−, SO42−, KMnO4 consumption, and electroconductivity), unambiguously showing that groundwater quality was primarily impacted by untreated sewage inflow and confirming nitrate’s tracer behavior in oxic environments. The spatial distribution of selected parameter concentration gradients highlighted the expansion and distribution of the contamination front. A numerical groundwater flow model (Vistas 4 and Modflow) was applied to determine the groundwater flow direction and the quantity of groundwater originating from different parts of the investigated area. Through four simulated groundwater extraction scenarios, Scenario 2, with an average extraction rate of 80 L/s from 12 wells, and Scenario 3, with an average extraction rate of 75 L/s and 4 additional wells, were identified as the most optimal, providing a sufficient quantity of adequately sanitary water.