Officials are sounding the alarm on salt runoff.
Road salt runoff can wind up in rivers and lakes, not just in Wisconsin but nationwide.
That salt elevates chloride levels in the water, leading to saltier water everywhere.
"We are starting to be a little more like our oceans." said Shannon Haydin, Stormwater Section Manager for the Wisconsin DNR.
While that might seem like a dramatic comparison, experts said we're approaching a dire situation.
"We are shifting towards a situation where eventually it could become unsustainable if the background levels continue." said Haydin.
Rock salt doesn't break down over time, it's not leaving our waters anytime soon.
According to data collected from the DNR, Lake Michigan has become about 7.5 times saltier since the 1800's, more than 70 percent of that salt pollution comes from five rivers, including the Fox and Milwaukee rivers in Wisconsin.
51 rivers in Wisconsin are considered chronically impaired.
Even one teaspoon of salt can pollute five gallons of water to a level toxic to freshwater ecosystems.
"Bugs that will eat the algae go away because the high levels of chlorides are too toxic for them and then we have these algae blooms."
It's even impacting fish, with the DNR reporting seeing smaller fish sizes in their fisheries.
It can even elevate sodium levels in drinking well water.
Experts are urging people to be mindful when salting their sidewalks and roads this winter.
