Tracking denitrification in green stormwater infrastructure with dual nitrate stable isotopes.

Strategies to mitigate watershed nitrogen export are critical in managing water resources. Green infrastructure (GI) has shown the ability to remove nitrogen from stormwater, but the removal mechanism is unclear. Denitrification removes nitrate from water permanently, making it the most desirable removal mechanism.

Green stormwater infrastructure redirects deicing salt from surface water to groundwater.

Winter deicing salt application has led to water quality impairment as stormwater carries salt ions (Na and Cl) through watersheds. Green infrastructure (GI) is a promising urban stormwater management practice, but its efficacy in managing salt is unknown. GI is not yet designed to remove salt, but may have potential to mitigate its loading to surface waters.