With an El Nino winter on the horizon, meteorologists are projecting a higher chance for a warmer and drier winter in the greater Chicago region.
While the winter might look different, the way the Lake County Department of Transportation prepares for potential snow and weather events doesn’t change, but the climate pattern is closely monitored to avoid over-salting the roads.
Environmental advocates and scientists are concerned about rising levels of chloride in wastewater and waterways, a consequence of using rock salt for decades to prevent roads from freezing over.
A highly corrosive material, salt dissolves well in water, making it the preferred, and most economical way, to melt ice.
However, the road salt eventually dissolves and accumulates in sewer systems, rivers and streams, ultimately harming aquatic life and vegetation, according to Thomas Minarik, principal scientist at the Metropolitan Water Reclamation District of Greater Chicago.
Corrosive road salt can even damage roadways, cars and infrastructure, added Jennifer Hammer, director of watershed programs for The Conservation Foundation and co-coordinator of the Salt Smart Collaborative.
“There’s all these different things that salt damages, but at this point we don’t really have a good alternative to salt across the board,” Hammer said. “We still need to use salt to keep our roads safe, so that’s a key piece here.”
Adequate practices and equipment are key to how municipalities, and people, can use salt in a conscientious way.
High chloride concentrations
A milder winter, with less storm events, could lead to less road salt use and lower rates of chloride loading into the water systems, Minarik said.
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Lake County and the northeastern Illinois region are leaning above normal for temperature and below normal for precipitation this winter, according to the National Weather Service’s Climate Prediction Center.
But the exact tracks and timing of storms are highly variable, so transportation departments are always at the ready.
Since November, the Lake County Department of Transportation has had snow plows staffed and ready to go in case of a weather event. The team has already gone out three times this season to plow — the most recent time being Sunday — which is earlier than last winter, according to Alex Carr, deputy communications officer for Lake County.
“For any snow season, no matter what predictions of weather conditions may or may not be, we’re staffed up and ready to go,” Carr said. “We are a 24/7 operation during the wintertime.”
The county is responsible for maintaining 280 miles of county roads, which make up 26 different snowplow routes.
As the climate change continues, Minarik said the more intensive storms lead to more ice and the need for more de-icing. In the springtime, heavy rains flush remaining road salt through the water systems.
State permit standards for wastewater discharge mandate chloride contamination levels cannot exceed 500 milligrams per liter at any time.
During the winter, Minarik said the department anticipates chloride levels to exceed the standard. Removing chloride from wastewater requires reverse osmosis, an expensive process, so he said it’s best to fix the problem on the front end, encouraging municipalities and residents to be conscientious with rock salt use.
“Safety is always the number one priority,” he said. “We want to make sure the roads are safe. It’s a challenge because (salt) is the most economical, efficient way to do it, but we’re learning now these trends are going the wrong way. If we don’t do something now, it’s going to be a problem for us in the near future.”
A little salt goes a long way
“Salt is absolutely a concern for us,” Carr said. “Conditions determine how and what is most effective, but whenever we can, we try to utilize best salting practices.”
Weather forecasts inform what concentration of brine formula Lake County sprays on the road, in an effort to reduce the use of road salt.
Brine — a combination of salt and liquid — can significantly reduce the amount of salt needed on the roads, and is typically sprayed as a pretreatment to prevent ice.
“Using salt alternatives like beet juice and salt brine can reduce the amount of salt needed by up to 30%,” said Kevin Kerrigan, maintenance engineer for Lake County.
Beet juice in brine helps reduce the freezing point of the brine, and adds a stickiness element to help it stick to the roads. Minarik, however, found beet juice clogs up his equipment, so use of alternatives can vary.
Residents can also make salt brine at home to reduce salt use. Hammer recommends following a recipe to get the correct ratio of salt to water. Prewetting sidewalks with brine makes the salt more effective while using less.
Hammer, who advises municipalities on methods to reduce salt use, said using newer plow equipment with capacity for liquid brine and pavement temperature sensors can help make better decisions in regards to salting.
At home, residents should only use what they need when salting driveways and sidewalks. One 12-ounce cup of rock salt is enough to cover 10 sidewalk squares or 20 feet of driveway.
“A little bit of salt goes a long way,” Hammer said.
It’s also important to monitor the temperature, because that affects the working ability of salt. At 15 degrees, rock salt doesn’t work to melt away the ice and residents should switch to a different product formulated for colder temperatures.
“You could put three times as much (salt) and it’s still not going to melt any faster,” Hammer said. “It’s about using the right product for the conditions.”
In Lake County, residents can monitor road conditions and see live video from the plows at https://www.lakecountypassage.com/. The transportation department asks that residents don’t crowd or pass the plows for safety reasons — the safest roads are behind the snowplows.