How salt use is impacting our lakes this year

How salt use is impacting our lakes this year

MADISON, Wis. - Some 23 million metric tons of sodium-chloride-based deicer is applied to North America's roads each year. Researchers say all of that salt then ends up rivers and lakes, and Wisconsin is seeing a growing problem with that.

Studies show Lake Mendota has about 25 times the amount of chloride it had before we started putting salt down around 80 years ago. Researchers have been monitoring the levels since then and say if we don't do something different soon the quality of our lakes will continue to go down.       

Once the lakes thaw out in the weeks ahead, researchers will be able to test the water to see exactly how much impact there is this year. It's hard for them to predict right now because we had such a quiet start to winter, but then of course we got slammed with constant snow and ice in February and early March. It was then many municipalities like Madison had no choice but to use salt when they normally don't.

UW limnologist and assistant professor Dr. Dugen says you can think of salt affecting lakes like salt affects humans; some of it is okay, but lots of it starts causing problems.

"Everything that lives in the lake is adapted to a freshwater environment, and animals just physiologically don't have the mechanisms to get rid of that salt from their bodies because they never had to deal with it in the past," Dr. Dugen explained. "The more salt we put in the lake the more we're just stressing out anything that's trying to live there."

Dr. Dugen stresses that there has to be more of an effort to reduce the salt load. She says it's not that we have to just stop using it; we just need to be smarter about where we use it and how much we put down. She says we obviously have to balance that with public safety.

Dr. Dugen says we at home all play a direct role in reducing the amount of road salt making its way into Wisconsin's lakes. More than 50-percent of the salt being put down is not by city, county or state plows but rather homeowners and businesses.

Phosphorus is still the number one polluter during the winter. Officials say farmers put manure out on frozen fields, but most of the nutrients end up washing into the rivers and lakes because of the fast winter melt. Dr. Dugen tells News 3 Now last week was a good example of that with the heavy rain and fast melt we had when anything and everything washed into area waterways.


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