It was below freezing on Wednesday morning as Greg Kimutis dropped a tin can into Richland Creek in Centennial Park in Swansea.
Kimutis is one of hundreds of volunteers who regularly test their local streams and waters for salt, through a statewide program called Winter Chloride Watchers. The program is one of multiple efforts to monitor how waters are affected by road salt applied during winter storms like the ones moving through St. Louis this month.
Kimutis’ reading Wednesday was relatively low, just 50 parts per million of salt, which is above what streams might see without humans around but not so high it could hurt animals or humans. Levels aren’t always so low across the rest of the St. Louis region.
“The highest readings that I've seen were actually in the range of what you find in the ocean,” said Danelle Haake, director of Illinois Riverwatch and an aquatic ecologist.
Excessive road salt and bad storage practices can lead to salty streams in the St. Louis region. That is harmful for aquatic critters, like bugs, but the problem can also move up the food chain because so many larger animals eat those stream invertebrates.
Haake has been studying salt in local water for more than 10 years. She said there are ways cities and businesses can change their practices to both protect streams and save money.
Webster Groves has been at the forefront of this effort. More than a decade ago, it was the first municipality in the area to adopt a different technique for salting roads, called brining. The city takes the same road salt it normally applies but dilutes a smaller amount in water, which is then sprayed on roads. The solution makes it harder for snow to stick to the road.
“I would say it's probably reduced our cost by 25% on what we spend annually on winter storm maintenance,” said Todd Rehg, a civil engineer for the city’s public works department.
Rehg and his colleagues are also trying something new this year; they have three new monitoring systems to keep track of hyperlocal weather and road temperatures, so Rehg knows exactly when the roads are going to freeze. The system means the city doesn’t have to pay overtime to employees waiting around for the right moment to salt the roads, and it also doesn’t have to apply extra salt because the first batch was applied too early.
Webster is also promoting their practices to other local cities. In October, the city held a workshop with the Deer Creek Watershed Alliance to show off their system.
“We had several municipalities that came to hear about what efforts we’re making and whether it's a good fit for them,” Rehg said. “And a couple of them were saying, ‘Yeah, we're gonna look at getting into this.’”
Seven other municipalities had joined Webster Groves in using brine as of 2022, according to the Metropolitan St. Louis Sewer District. Those are Ballwin, Bridgeton, Hazelwood, Jennings, Ladue, Richmond Heights and University City.
But it’s not always possible to brine, especially during winter storms that start with rain, like the ones the region has experienced this week. That means Webster still uses salt sometimes.
“It's been raining for the last 12 hours, so we could not brine before this storm,” Rehg said Tuesday evening. “It's just now starting to turn over to snow, so we are out, putting salt down, at a light amount.”
Haake said there are other things cities and businesses can do to keep salt out of nearby streams, including covering piles of salt so rain doesn’t wash it away and just using less salt when it’s needed.
“Most businesses that I've seen, they tend to overapply the salt,” Haake said. “They use a lot more than they need.”
People can also reduce salt in the environment at home, by applying reusable sand on sidewalks and driveways, or making their own at-home brine to spray outside.
