It’s no secret that water quality is important to a lot of us who chose to live in the Land of 10,000 Lakes. And it’s also no secret that bodies of water all over the state are facing a broad array of threats whether it’s from aquatic invasive species or mercury pollution from coal-fired power plants. But did you know that salt is an emerging threat when it comes to water quality, especially in more urban areas?
It is a well-known fact among Minnesotans that salt on roads and driveways helps to clear them of ice and snow making them safer. Unfortunately, as ice and snow melt, they carry the salt along with other pollutants into nearby waterways. This is adding to the problem.
The Minnesota Pollution Control Agency has shown that 30% of wells in the Twin Cities Metropolitan Area have too much chloride pollution already. Furthermore once salt gets into water it stays there, and as concentrations build up it can become harmful to various fish and plants.
The good news is that we can all take steps to reduce the amount of salt used, and thus the amount of pollution created, without making our roads and sidewalks less safe. These include:
- Shovel or snow blow without salt as this is often enough to keep sidewalks and driveways clear.
- Wait until temperatures rise because salt doesn’t work as well when it’s lower than 15 degrees.
- Use less salt and place it strategically. Too much salt and salt on dry pavement will not help.
- Work with your local government to develop plans for your community on salt use.
And, when in doubt, look to the experts. The Minnesota Pollution Control Agency recommendation states to, “Use less than 4 pounds of salt per 1,000 square feet (an average parking space is about 150 square feet). One pound of salt is approximately a heaping 12-ounce coffee mug. And to be sure its applied well, consider purchasing a hand-held spreader to help you apply a consistent amount.” https://www.pca.state.mn.us/water/road-salt-and-water-quality
Safety is obviously the first priority when it comes to transportation, but more salt on the roads doesn’t necessarily equal more safety when it’s applied incorrectly.
For more information on salt use feel free to check out this video from the Mississippi Watershed Management Organization or this hand out from the Nine Mile Creek Watershed District.