The hidden high costs of road salt
Winter is inevitable. Environmentally harmful winter maintenance practices don’t have to be.
De-icing salt plays an important role in winter safety. We use it on our roads, parking lots and walkways to prevent collisions, slips and falls. What you may not know is that the de-icing salt we use in the winter doesn’t just disappear come summer. Instead it soaks into the soil and washes away into our lakes, rivers and streams with the spring snowmelt. Our plants and local aquatic wildlife, like fish, frogs and turtles aren’t too happy about it. We shouldn’t be either.
Summer’s Top Hot Spots
In 2019, the WWF released a map highlighting the top summer hot spots in the Great Lakes region. And no, they weren’t referring to the most popular beaches. The map shows local waterways showing record high chloride levels in the summer due to high use of de-icing salt in winter. CVC’s real-time watershed monitoring stations also report high concentrations of chloride in our lakes, river and streams like Sheridan Creek.
We won’t make you dig up your high school chemistry textbook, but de-icing salts are made from sodium, calcium and magnesium chlorides. There are three important things to know about chloride-based salts. First, they’re highly soluble in water. That means they dissolve easily. Second, high concentrations of chloride are toxic to plants, mammals, amphibians and fish. And third, there’s no easy way to remove chloride salts from freshwater. There’s no easy fix once the damage is done.
So, what can we do?
The good news is there are things we can do to reduce our use of de-icing salt without compromising winter safety.
- Shovel first, salt second. Less snow means less salt is needed to keep walkways and laneways clear.
- Simply use less. You only need to use a small handful per square metre.
- Check the temperature. De-icing salt is less effective at temperatures below -10 °C.
- Advocate and educate. Ask your employer, landscape contractor, local businesses and institutions if they are Smart About Salt. Train your staff how to be Smart About Salt or share this information with your neighbours.
Businesses and institutions have a great opportunity to prevent chloride pollution by enhancing their properties and winter maintenance practices to support the reduced use of de-icing salt. Installing permeable paving, cordoning off underused walkways and parking lots, and hiring Smart About Salt certified winter maintenance contractors are just some of the things they can do. Watch or share this video with your employer or property management team to get started.
What will you do to protect our soil and waterways this winter? Tell us here.
By CVC’s Calantha Elsby, Specialist, Environmental Outreach