Influence of pumping saline groundwater on land-sourced solute transport in coastal aquifers.

This article focuses on the effects of saline groundwater (SGW) pumping, also known as negative hydraulic barriers, on seawater intrusion (SWI) control and the transport of land-sourced solutes in coastal aquifers. Using a variable-density, multi-species transport numerical model, the study finds that while SGW pumping effectively mitigates SWI by altering flow dynamics and creating hydraulic barriers, it also increases the depth, area, and residence time of land-sourced solute plumes by redirecting their migration downward toward pumping wells. The research further shows that pumping rate, well location, hydraulic conductivity, and dispersivity significantly influence both SWI control and solute behavior, with higher pumping rates and wells closer to contamination sources reducing solute accumulation but potentially expanding saltwater intrusion downstream. These findings highlight the need for optimized SGW pumping designs that balance SWI prevention with minimizing land-sourced pollutant buildup, while noting limitations such as the exclusion of complex hydrogeological factors and recommending future 3D modeling for real aquifers.