Salt is not good for Minnesota’s waters or wildlife. However, it does keep roads and walkways from getting too slick and hazardous in the winter.
As far as harm goes, a little goes a long way. One teaspoon of salt can pollute up to 5 gallons of water.
The same is true the other way — it doesn’t take much salt to help promote melting.
In fact, the Minnesota Pollution Control Agency says more salt doesn't mean more melting. Salt is only effective down to about 20 degrees Fahrenheit. According to the MPCA, 4 pounds of salt is adequate to de-ice 1,000 square feet. One pound of salt fills a 12-ounce coffee mug.
For most effective application, salt grains should be spread out. Try to leave about 3 inches of space between salt granules. Sweep up excess salt after applying. If salt is still visible on dry pavement, it’s no longer necessary, and will end up in waterways during the next rain or melt.
These tips and more detailed salt application training are offered by the MPCA through its "Smart Salt" training, available for individuals or organizations.
Smart Salt training helped Mayo Clinic cut salt usage on its campuses. That, along with other changes, brought salt use down 60% last year on Mayo campuses compared to the previous year.
ALSO READ: Mayo puts campus on low salt diet
Some products offer an alternative to salt, such as “PlaySafe Ice Blocker," a calcium magnesium acetate and potassium acetate mixture.
The MPCA lists 50 stretches of about a dozen bodies of water in the state as impaired due to chloride in the water. Chloride is toxic to freshwater plants and animals. It can hurt crops and damage soil. It can also make water more corrosive and increase lead levels in water.
Most of the polluted bodies of water are in and around the Twin Cities metro area. However, that doesn’t mean there isn’t chloride pollution in other bodies of water. However, testing is limited, so like the MPCA’s Smart Salt training, a targeted approach to address salt pollution is required.
The Izaak Walton League offers salt testing kits through its Winter Salt Watch program. Participants are asked to post their results and photos of their testing sites at www.waterreporter.org.
You can see the results on the Izaak Walton League’s website.
For best results, volunteers are asked to choose one location to test four times. For a flowing body of water, volunteers should choose a site downstream from a roadway. On a lake, people should try to take samples away from the shore or from a dock.
Most water quality testing is carried out during other months, and not always for chloride. Finding out if chloride is affecting a waterway near you could help identify a problem local officials might not even know exists.
We all rely on clean water for a healthy environment. We can all play a role in protecting and monitoring our water.
John Molseed is a tree-hugging Minnesota transplant making his way through his state parks passport. This column is a space for stories of people doing their part (and more) to keep Minnesota green. Send questions, comments and suggestions to firstname.lastname@example.org.