For years, doctors have told people to stick to a low-salt diet. According to the Minnesota Pollution Control Agency (MPCA), our waters should follow the same advice.
When snow and ice start to accumulate on Minnesota roads, parking lots, and sidewalks, one of the more common reactions is to apply salt, which contains chloride--a water pollutant. When snow and ice melt, most of the salt goes with it, washing into our lakes, streams and rivers. Once in the water, there’s no way to remove the chloride, and it becomes a pollutant.
According to Brooke Asleson, MPCA project manager for the Twin Cities Metro Area Chloride Project, “salt is a real threat to water quality. It only takes one teaspoon of road salt to permanently pollute five gallons of water. We are trying to spread the word that less is more when it comes to applying salt because at high concentrations, chloride can harm the fish and plant life in our waters.”
Check out the MPCA's video on winter sidewalk and driveway maintenance, with tips on types of salt, when to use it and how much to use:
Here are some ways for homeowners to reduce salt use while still making sure your sidewalk and driveway is safe:
- Shovel. The more snow and ice you remove manually, the less salt you will have to use and the more effective it can be. Break up ice with an ice scraper and decide if application of a de-icer or sand is even necessary to maintain traction.
- More salt does not mean more melting. Use less than four 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.
- 15 degrees is too cold for salt to work. Most salts stop working around this temperature. Instead, use sand for traction.
- Sweep up extra salt. If salt or sand is visible on dry pavement, it is no longer doing any work and will be washed away.
To learn more about what you can to reduce chloride in our waters, visit the agency’s Twin Cities Metro Area Chloride Project webpage.