Winter Stormwater Safety 

The Scoop on Road Salt: How Chlorides Impact the Environment
Road salt is an important tool to keep roads safe during winter weather. It can speed up snow and ice melting, making it easier for plows to clear the roadways. More than 428,000 tons of road salt was used on Illinois roads during the winter of 2019-2020. While salt is important for safe winter roads, excess salt use can hurt local waterways.

Why should we care about too much salt?
Salt, or sodium chloride, is very water soluble, meaning it easily dissolves in water. This is why it is effective at melting snow and ice. However, this also means it can easily impact the water quality of nearby rivers and streams. A single teaspoon of salt is enough to contaminate five gallons of water. Once salt dissolves it does not degrade over time. In fact, salt is very challenging and costly to remove from water, essentially making it a permanent pollutant. 

Too much salt in water has environmental impacts. High chloride concentrations can impact local aquatic life, like fish, insects and freshwater mussels, by inhibiting their ability to successfully reproduce and survive in local waterways. Even at chloride concentrations as low as 150 mg/L (about ½ teaspoon of salt in 5 gallons of water), local watershed groups have documented impacts to aquatic communities.

High salt concentrations also affect plants. Road salt can kill plants, like grass next to sidewalks and trees along our roadways. It can impact the soil along our roadways making it difficult for plants to grow. It can be costly to repair and replace the “salt burned” plants and very difficult to neutralize the impacts of chlorides in soil. Aquatic plants are impacted too—high salt concentrations can lead to a die-off of native aquatic plant species. 

High concentrations of salt in our drinking water impact people too. We begin to taste salty water when the concentrations are above 250 mg/L, which is the drinking water standard for chloride. Too much salt in our water can lead to health problems for those who need low-sodium diets. 

Salt is also corrosive. It causes damage to our bridges, roads, vehicles, and building entryways. Also, high chloride concentrations in drinking water can damage metal pipes.

What are communities doing about salt pollution?
Many communities use improved winter maintenance practices to provide safe roads, while reducing the amount of salt they use to reduce their impact on local waterways regardless of regulatory requirements. 

Communities implement practices like anti-icing (which uses a quarter of the amount of salt compared to de-icing!) to make it easier to plow snow and ice from our roads. Anti-icing prevents snow and ice from sticking to the pavement in the first place. They train their staff on these improved winter maintenance practices. They work to upgrade their good housekeeping techniques to help reduce excess salt runoff at their facilities. 

Communities also get residents involved. Public education goes a long way to reduce salt use on home driveways and make small changes like working from home during a snowstorm or building in extra time to their commute so they can give plow drivers a chance to get the roads cleared. 

Finally, many communities participate in watershed workgroups to learn from each other and work together to improve our local waterways. By coming together, we can make greater gains to protect rivers and streams across our region. 

Also Read - How Winter Salt Affects Pets

Videos 

DuPage County Stormwater Management recently produced a variety of water quality educational videos that are available for public viewing on Stormwater Management’s “Love Blue. Live Green.” YouTube page: https://www.youtube.com/user/lovebluelivegreen

The videos, along with past webinars, are also organized under the “Playlists” tab. 

Brochures & Information Guides

After the Storm - A Citizen's Guide to Understanding Stormwater
Citizen Monitoring - Illicit Discharge Detection
Car Wash Guidelines - Send Only Rain Down the Drain
Proper Pet Care - Managing Your Pet's Waste Safely
Sustainable Lawn Care Practices
DuPage County - Stormwater Brochures & Information