Applications of Modeling Non-point Source Pollution in Groundwater

Modeling non-point source (NPS) pollution in groundwater is a critical yet challenging task, particularly at large regional scales, due to the high computational costs and the need for detailed loading data across the entire area. This work focuses on the development and application of the novel Non-Point Source Assessment Tool (NPSAT), a physically based and computationally efficient framework for simulating groundwater flow and diffuse pollution/tracer transport processes. By integrating regional-scale hydrologic models, high-resolution landscape recharge and pollution/tracer loading models and high-resolution well placement models with particle-tracking and reactive transport frameworks, the NPSAT addresses complexities such as spatial variability and anthropogenic influences on groundwater transport across local to large regional scales. Two key applications are highlighted: groundwater age modeling, which refines our understanding of aquifer porosities and flow velocities, and nitrate transport modeling, which evaluates contaminant movement and attenuation under varying agricultural practices. These advancements demonstrate the potential of cutting-edge groundwater modeling approaches to tackle emerging issues in water resource sustainability and pollution mitigation.