When snow melts, salt applied to melt snow on sidewalks, roads, and parking lots can make its way to streams. Freshwater critters don’t like living in saltwater. Are we getting to a point where they’d have trouble? Not quite, the chronic levels of concern for Iowa is 389 mg/L of chloride, and this sample (from a creek near Ames High School) and some others in our area were just shy of that last weekend. But be mindful of how much salt you’re scattering if we get some more icy days this month–people often apply more than what’s needed for safety!
The Izaak Walton League’s Winter Salt Watch is a good way for people to check on water quality during the winter and learn more about the issue.
What else is being carried in snowmelt? Our lab tests from late February are showing higher nitrate and bacteria levels than January’s tests. Check back in mid-March and we’ll get that data organized.