MAPLEWOOD, Mo. – During winter, road salt is applied to melt snow and ice on our streets. But as stream ecologist Dr. Danelle Haake realized back in 2009, it doesn’t stay there.

“One winter afternoon, we were doing some sampling and found really high chloride in the streams,” Haake said. “And it just took us a few minutes to realize, ‘Oh, it snowed a couple of days ago.’”

Melting snow was carrying the salt into the stream. Haake and other Missouri Stream Team volunteers began tracking chloride levels at sites across St. Louis County, like Deer Creek in Maplewood. Ten years later, their research findings were recently published.

“Along with three of the citizen scientists, who are just everyday people, they don’t have a professional science background, we wrote a paper together that’s been published in an academic journal.

Data shows that roads and highways aren’t the only significant contributors to stream chloride levels. In larger urban areas, sidewalks and large parking lots may contribute even more.

“If you walk across a parking lot in the winter, sometimes I find that I’m as likely to fall on the accumulated salt as I am on any ice,” Haake said.

More and more, street and highway departments are using brines, which allow less salt use for the same results. Dr. Haake hopes commercial businesses will follow suit to protect the health of streams.

“Beyond a certain level at least, salts become toxic to plants as well as to animals. So, animals that live in a freshwater stream don’t want to live in a saltwater stream,” he said. “So, they’ll actually start dying out and we’ll have a decrease in the small animals, the invertebrates, that live in the water. And that will decrease the numbers of birds and fish that can rely on that as a food supply.”

Dr. Haake is now RiverWatch Director at Lewis and Clark Community College’s National Great Rivers Research and Education Center in East Alton. She has expanded the chloride monitoring program into Illinois and is looking for more volunteers.

“It’s something that any age can participate in. The actual sampling is pretty simple, it takes maybe 10 or 15 minutes,” she said. “You just take a quick water sample, read what the results are, and we have an app that you can put the results in on your phone.”

If you’d like to volunteer to be a citizen scientist and help Dr. Haake with her research, you can email her at and she’ll point you in the right direction.