Reduce salt use to keep chlorides down in drinking water

Winter Salt Awareness Week was, Jan. 27-31, the public is invited to learn more about the impacts of road salt on drinking water and freshwater ecosystems.

Although salt keeps Wisconsin roads safe during winter, using more salt than needed comes at a price. In Wisconsin and much of the U.S., chlorides from salt are infiltrating lakes, streams and groundwater.

According to Wisconsin Salt Wise, one teaspoon of salt, is all it takes to make five gallons of water toxic for freshwater organisms.

The DNR measures chloride levels in Wisconsin rivers over time. Recent studies have shown a steep increase in chloride loads. In the early 2000s, the DNR measured about 600,000 tons of chlorides annually. By 2018, that number increased to nearly 800,000 tons, per year.

Now, 50 rivers and streams, and one lake in Wisconsin, have been designated as impaired by high chloride concentrations, primarily from salt used during winter.

“All 43 of the long-term trend water quality monitoring sites across Wisconsin, are showing increases in chlorides,” said Shannon Haydin, DNR storm water section manager. “Chlorides persist in the environment forever and cause significant impacts to fish, aquatic life and hu man health.”

In Wisconsin, evidence of Fresh Water Salinization Syndrome is showing, which is a condition where freshwater becomes more like ocean water, in terms of its saltiness.These increased chloride loads are partly from road salting, but chlorides also enter Wisconsin waters, because of water softeners and fertilizers.

Increased chloride levels have significant impacts on daily lives, including environmental and economic ef-fects. Nationwide, winter salt causes $5 billion in damage to infrastructure each year, causing corrosion of bridges, roads and other infrastructure. Road salt can also impact pets, by causing irritated paws or other health concerns, if ingested.

In Wisconsin, 39 percent of the community wells exceeded the Wisconsin Department of Health Services’ recommended sodium level, for individuals on a low-salt diet of 20 mg/L, at least once since 2004. This can mean individuals managing diseases by limiting salt intake, may take in more salt than they may account for.

The following steps can be taken to right-size salt use:

• Clear walkways and other areas before the snow turns to ice. The more snow removed manually, the less salt needed and the more eective it will be.

• When using salt, scatter it so there is space between the grains. A 12-ounce coee mug of salt, is enough to treat an entire 20-foot driveway or 10 sidewalk squares.

• Salt is much less eective when pavement tempera tures drop below 15 degrees. Switch to sand for traction or a dierent ice melter that works at lower tempera tures.

The DNR works to reduce chlorides at the source, through permitting programs for municipalities and industries. These measures include tuning or replacing water softeners, identifying significant chloride contrib -

utors and finding reductions, process eciencies or im provements, by instituting sewer use ordinances.

Additionally, the WisDOT works with Wisconsin counties, to reduce road salt application, using brine and pre- wetting road surfaces, significantly reducing salt use.