Snow is a fact of life in Minnesota, and so is using rock salt to melt all the snow and ice. But did you know that road salt and deicers are an environmental pollutant?
Road salt is used in the winter to change the melting point of ice, making it lower and thus preventing it from freezing at lower temperatures. Salt and water combine very easily, which is good news for melting sidewalks ice, but that strong chemical bond makes the chloride from salt molecules nearly impossible to remove from water.
So, when chloride dissolves into lakes and rivers via sidewalk runoff or melting snow, it is considered a permanent pollutant. Every winter, when salt melts downstream, chloride concentrations in our waterbodies increase. And studies from the Minnesota Pollution Control Agency (MPCA) are showing that elevated chloride levels in surface water is toxic to fish. Salty water runoff from road salt can disrupt entire freshwater ecosystems.
As of 2022, local waterbodies including Sand Creek, Raven Stream, and Credit River are all listed on the MPCA’s impaired waters list for chlorides.
Just one teaspoon of salt is enough to permanently pollute five gallons of water, so by reducing salt use by just one cup, you are saving nearly 250 gallons of water from being polluted.
Things to know before it snows:
Be mindful of temperature
If you do need to use salt on sidewalks or driveways this winter, remember that Temperature is KEY. Pure rock salt can only melt ice if the pavement is above 15 degrees Fahrenheit. In colder weather, use different types of de-icers if necessary.
By making a couple of adjustment to winter routines, the impacts that can be made both positively and safely to improve water quality are immense.
To learn more about smart salting techniques on both large and small scales, visit scottswcd.org/chloride.
Watch our webinar
The Scott SWCD and the Scott Watershed Management Organization partnered together last year to host a mini "Homeowner Winter Management" webinar on the topic of chloride pollution.
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