Road salt to make icy roads safer can harm aquatic ecosystems, Illinois RiverWatch director says

We are entering the road-salt season. But that salt — meant to treat roads and sidewalks — often ends up in waterways, where it can harm aquatic life.

The Illinois RiverWatch Network is tackling this problem with citizen science, training anyone who’s interested to monitor those levels. Their program is called Winter Chloride Watchers.

Danelle Haake, director of Illinois RiverWatch, spoke with WBEZ’s Melba Lara about what’s being done.

Melba Lara: Let’s start with road salt. How exactly does it impact aquatic ecosystems?

Danelle Haake: The salt that we put on the roads ends up dissolving in the snowmelt and ice melt. And then it’s carried through the stormwater system into local rivers and streams.

There’s no treatment process to remove the salt. So it increases the salinity — the amount of chloride in the water. It doesn’t usually get to the point where it’s the same as ocean water or seawater, but it does make it more of a saltwater system than a freshwater system for what our invertebrates are looking for.

Lara: What aquatic life is affected?

Haake: Really, all the aquatic life. Specifically, it tends to cause a problem for the aquatic invertebrates — the insects that live in the water. But if we are damaging our insects, that’s the food base for our fish. And the fish and the insects combined are the food base for a lot of waterbirds. And so this is really something that affects the whole ecosystem.

Provided

Provided

Lara: Municipalities use it every winter to make it easier and safer for us to get around. How can road salt be used responsibly?

Haake: The use of road salt is better when done in moderation. There’s an amount that’s kind of prescribed. If we go over that amount, we’re really just wasting the resource, and we’re wasting money and causing damage to so many different things.

Lara: Tell us what the Winter Chloride Watchers do.

Haake: Participants in Winter Chloride Watch take a little water sample from a river or stream, and then they put a small test strip into that sample. They wait for the water to wake up the little material in the test strip. And then they come up with a number, and that number tells us how much salt is in the water.

Lara: We often think of science happening just in an academic setting. Why is empowering everyday individuals to collect data around something like this important?

Haake: There’s several reasons to have citizen scientists or community scientists working on this project. It’s something that — it’s very understandable for people. You know, you can see the salt yourself. And then we just draw the link of: This salt goes into your rivers and streams and changes what can live there. So it’s an easy connection to make, and it’s something that people care about.

In addition to that, scientists can’t be everywhere at once. We can’t collect all of the data everywhere. So having these people — volunteers out monitoring — can help us pinpoint places where maybe we need to do a little extra work.

Lara: What got you interested in this work?

Haake: I actually got into road salt as a volunteer, as a citizen scientist. I was working with another group of volunteers, and we noticed high chloride concentrations, and I said: This is really bad. This is a lot higher than it’s supposed to be. The amounts were more than four times what could be toxic to aquatic life. And so I contacted some other volunteers, and they said, yeah, we’re seeing the same thing. And it kind of expanded from there.

And I ended up getting a Ph.D. looking at road salt because of this community science project.