Monday’s snow was a reminder that while the holidays are over, the winter season certainly is not. With more snow possible this weekend, hundreds of tons of salt will be dispersed on roads and walking paths across Lake County, highlighting a growing concern over waterway salinity in the region.
Aaron Packman, a professor of civil and environmental engineering at Northwestern University and the director of the Northwestern Center for Water Research, said that while road salt doesn’t pose undue risk to local wetlands or Lake Michigan, there’s been a documented effect on the region as a whole.
“Generally speaking, across the northern part of the U.S. and Canada, there’s been a noticeable increase in background salt in all the waterways,” Packman said. “If you look at smaller lakes, for example … they’re getting saltier over time.”
Although the increased salination doesn’t impact drinking water, there are concerns for native ecosystems vulnerable to salinity, especially for inland lakes where salt can build up. Over the decades, there’s been a “slow, progressive, long-term change in salt concentrations,” he said.
“Think Minnesota, for example, the water coming from the snow belt has historically been very pure, high quality,” Packman said. “You start adding salt to those lakes — that’s a significant shift in the ecosystem condition.”
It’s an issue seen, “in basically every environment that has a lot of snowfall,” he said. However, it’s a difficult problem to address.
Salt use is “ubiquitous wherever you have traffic,” Packman said, and while there are some alternatives, such as using sand, they can’t match the simplicity, cost and effectiveness of salt. Municipalities that moved to reduce salt use or find alternatives often return to excessive salting of roads over cost and safety concerns, he said.
But as salt levels continue to rise in waterways, concerns have continued to grow. Packman advised finding a middle ground.
“There’s a real question here of balancing safety and convenience versus long-term degradation,” he said. “We cannot just continuously salt and make all the lakes and smaller rivers saline. That would be a real problem long-term. I would aim for solutions, either alternatives or more limited salt applications that better balance safety with sustainability.”
Lake County winter storms
Kevin Kerrigan is the engineer of maintenance at the Lake County Department of Transportation, which handles winter maintenance for the county highways and secondary arterial roads.
Working with the National Weather Service, Kerrigan said once county officials get an alert, they begin calling in a crew for snow-plowing, which can consist of up to 26 plow truck drivers and about three mechanics.
This season alone, Kerrigan said the county has put out about 2,300 tons of salt over about 14 calls, just for the roadways under the county’s jurisdiction.
“Every storm is different,” he said, requiring different methods. An ice storm, for example, requires far more salt than a snowstorm. And during bigger storms, Kerrigan said they’re often only salting intersections, since crews are regularly plowing the roads and would remove any salt.
Today, modern technology allows trucks to be more efficient and effective with salt usage, with calibrated computers controlling the drop of salt on specific roadways.
The county has also made efforts to reduce road salt and other deicing materials in general. Several departments team up every year to offer “deicing workshops” to public agencies and private contractors according to the county website, showing how to use road salt in a way that will reduce the environmental impact.
Last year, Lake County partnered with the Salt Smart Collaborative, a group dedicated to addressing the “growing impacts of chlorides” on surface and groundwater resources, to host multiple in-person and virtual workshops on reducing salt in snow operations. More workshops are planned in 2025.
