Cut back on de-icer to protect Minnesota waters

Too much salt isn't just bad for our physical health, it's also a big problem for our environment. As we strive to keep sidewalks and driveways safe from slips and falls, we also need to think of our drinking water and fish populations.

With the wintry mix the Northland serves up, using salt or other chemical de-icers is the norm. But when the snow melts, de-icing salt containing chloride runs into storm drains and into rivers, groundwater and, of course, Lake Superior.

"Every bit of salt we put down on our sidewalks ends up in our water, one way or another," said Lucie Amundsen, Minnesota Pollution Control Agency's Duluth regional public information officer. "The best practice is to simply use less. You can do that by shoveling snow first and then applying sand or poultry grit. Salt should be used only when it's truly needed to melt an ice patch."

These best practices are essential, given it takes only one teaspoon of salt to pollute five gallons of water permanently. There is no feasible way to remove chloride once it gets into the water. Researchers are finding increasing amounts of chloride in our Minnesota waters. Salty water can foul wells and create a caustic environment for freshwater fish and other aquatic wildlife.

However, there is some good news when it comes to reducing our salt habit. Scattering salt lightly, leaving about three inches of space between grains, will still effectively remove ice. It takes only a coffee mug full of salt (about 12 ounces) to treat a 20-foot driveway or 10 sidewalk squares (roughly 1,000 square feet). Also, a frequently missed step is sweeping up any extra de-icer product that is visible on dry pavement. It is no longer doing any work and if left on the ground will only be washed away into local waters. And good news – it can be reused the next time your walk requires de-icing.

City of Duluth program coordinator Todd Carlson is a member of the Regional Stormwater Protection Team (RSTP) and believes that education is a key component.

"We've developed a Salt Smart sticker that's a visual reminder that it takes very little de-icer product to get the job done. People in our region have great respect for our creeks, streams and lakes, and we tend to do better when we know better."

Salt effects on our freshwater fish

When salt (sodium chloride) is concentrated in water, it immediately stresses the creatures in that environment. Aquatic insects, such as mayflies, feel the impact first. They're sensitive to chloride and die with little exposure. When the mayflies are gone, it eliminates a prime food source for fish, like trout.

Also, some fish and amphibians lay their eggs in the water. Eggs exposed to chloride have poor success rates, endangering future populations of these species.

Best Practices

• Shovel. The more snow and ice you remove manually, the less salt you'll need and the more effective it will be.

• Consider use of sand and poultry gravel for traction when below 15 degrees when most salts are ineffective.

• Slow down. Drive for the conditions and make sure to give plow drivers plenty of space to do their work. Consider purchasing winter (snow) tires.

• Hire a certified Smart Salting contractor. Visit the MPCA's Smart Salting webpage for a list of winter maintenance professionals specifically trained in limiting salt use.

• Promote smart salting. Work together with local government, businesses, schools, churches, and nonprofits to advocate for reducing salt use in your community.

Following are online resources for further information.

Resources for homeowners to reduce salt use at home: https://www.pca.state.mn.us/water/reduce-your-salt-use-home

The basics about chloride pollution, where it's a problem in MN waters, and how it harms the environment: https://www.pca.state.mn.us/water/chloride-101

Resources for educating people about chloride pollution and more: https://www.pca.state.mn.us/water/statewide-chloride-resources