Stormwater infiltration BMP impacts on groundwater quality

Project Status
Project Contact(s)

In cooperation with DelDOT, DGS is investigating the physical and chemical impacts of de-icing practices (salting and brining) and stormwater infiltration best management practices (BMP) on groundwater. The goal is to advise DelDOT on potential risks to groundwater quality from de-icing and inform changes to de-icing materials and practices. This project arose because of increasing chloride concentrations observed in a number of groundwater-supplied water systems in New Castle County. Increased concentrations of radionuclides and radiation are observed in some of the impacted water sources.

This is expected to be a multi-year project performed in a phased approach.
The first phase of this project is limited in scope due to funding and scheduling issues. Tasks include:
conduct GIS analysis to select two to four sites for initial site characterization and monitoring;
characterize the sites by installing a limited number of test borings and analyzing the physical and chemical properties of subsurface materials from those borings;
install a limited number of monitoring wells and groundwater sensors;
collect and analyze the salt content of a limited number of stormwater and groundwater samples;
evaluate data to choose sites for comprehensive field monitoring; and,
design the comprehensive study for the selected sites.
Future phases of the project will conduct the field monitoring study and use statistical and simulation tools to evaluate the risks of de-icing practices on groundwater.