Road Salt, Chloride, and our Rivers
​
Chloride is one of the main ingredients in road salt. Unlike many pollutants, chloride does not biodegrade or evaporate. Once it enters the environment, it stays there. We currently use more road salt than is necessary for effective winter road safety. Just one teaspoon of salt can permanently pollute up to five gallons of freshwater. Rain, melting snow, and stormwater runoff carry salt from roads, driveways, and parking lots into nearby waterways, which can eventually reach drinking water supplies. Once salt is in our rivers and groundwater, it is extremely difficult and costly to remove.
New Hampshire, Vermont, Massachusetts, and Connecticut are all part of the Northeastern "salt belt" that employs various strategies to de-ice roads in winter, including pre-wetting with salt brine, using snow-fighting vehicles with calibrated spreaders, and applying different types of salt based on temperature and storm conditions.
Monitoring Program
Connecticut River Conservancy participates in Salt Watch, a national chloride monitoring program run by the Izaak Walton League of America.
Salt Watch helps gather data on how road salt use affects water quality by measuring chloride concentrations in rivers and streams throughout the watershed. This information allows CRC and partners to identify hotspots of salt pollution, track trends over time, inform municipalities, and support smarter, more efficient salt use.
Effects on Wildlife
Many freshwater organisms including fish, amphibians, reptiles, insects, and aquatic plants are not adapted to survive in salty conditions.
Elevated chloride levels can:
-
Disrupt reproduction and growth
-
Alter species composition in streams and wetlands
-
Reduce biodiversity
-
Change water chemistry over time
​
Understanding where chloride levels are rising helps scientists and communities take action before permanent damage occurs.
