Road salt can harm the environment. So is there a better way to treat roads? Experts have ideas.
Salt is essential to keeping our roads safe during snowy, cold weather, but our use of the chemical takes a lofty environmental toll -- road salt can contaminate drinking water, endanger wildlife and damage property.
To tackle the harm of sodium chloride runoff on our environment, experts focus on minimizing the amount of salt used while keeping roads and walkways safe. That's because there isn't a chemical or product that could be used as a practical or safer alternative.
"It has been a difficult issue to address until recently because, for a long time, I think a lot of people thought we couldn't do anything about chlorides because of the public safety component. We need to use road salt to keep people safe, and that's absolutely true," said Jennifer Hammer, the director of watershed programs for the Conservation Foundation. "It really is about getting out good practices that we could be doing to help reduce the amount of chlorides going in."
Scott Kuykendall, a water resource specialist for McHenry County's planning department, said while safety continues to be the No. 1 priority in how roads are managed, the amount of salt that's being used is unnecessary.
"We absolutely positively need to maintain safety, but what we're doing right now is not providing that safety. We're just unnecessarily overloading our paved surfaces with salts and other chemicals," he said.
"These are not benign materials. You've got sodium chloride, which is your typical road salt. You also have calcium chloride and magnesium chloride. Each of these are toxic chemicals that have profound impacts and destroy infrastructure."
The reason salt runoff is such a concern among conservationists and water resource specialists alike is that once salt enters an ecosystem, it is practically impossible to take it out.
"Salt is very soluble. It's going to dissolve in water, which means once we apply it to the roads, it's got to go somewhere. It's got to go to the surface water bodies, to the groundwater or to the soil water," said Walt Kelly, a groundwater geochemist with the Illinois State Water Survey. "It's going to get into our water supplies no matter how we put it on."
Kelly said that while the chemical is not necessarily a health concern once it contaminates groundwater -- which many communities still rely on for drinking water -- but if enough salt concentrates in the groundwater supply, that drinking water will begin to taste salty.
The effect on our natural ecosystems is more pronounced, often lowering biodiversity.
Salt can dry out natural vegetation, killing native plants and trees that aren't used to the high levels of sodium. In large amounts, the chemical can kill fish, amphibians and other wildlife in our lakes, wetlands and other waterways.
"Even small amounts will kill the phytoplankton and zooplankton and macro-invertebrates and other things lower in the food chain," Kuykendall said. "The base of the food chain gets knocked out, which then affects all the other creatures higher up in the food chain. So even small amounts of chloride in the water can have profound impacts on the health of the ecosystem."
As far as regulation, Hammer said the Illinois Environmental Protection Agency encourages counties and municipalities to find ways to reduce their use of road salt. Many Chicago-area communities are additionally subject to specific best practices under recent changes to chloride-level standards.
Those best practices include annual training, outreach on chlorides and annual reporting on progress.
Kuykendall said one of the best strategies municipalities can adopt is applying a salt brine liquid mixture to roads both before and after icy storms. The mixture typically consists of salt brine, liquid calcium chloride and beet juice, which all work together to use less salt more effectively.
"For the liquid-only routes, a 38% reduction in chlorides also translates into a 30% reduction in cost, so each of those routes are saving significant tax dollars as well," Kuykendall said. "We're making the road safer, we're causing less pollution and we're saving taxpayer dollars."
While local government use of road salt has some amount of oversight, private use of salt has zero regulation. It's often the case that private companies are actually motivated to use more salt, to avoid accidents outside their businesses.
"It's not just roads -- every paved surface has to be managed in winter. When you think about the amount of paved surfaces we have for our stores and businesses, it's just a massive amount of paved surface that is having a salt applied to it," Kuykendall said. "We want to fundamentally change the way parking lots and sidewalks are managed in wintertime."
To help educate and train both business and professional contractors who clear and salt private spaces, Hammer is leading an initiative to develop a regional training and certification program as well as a manual of best practices.
Hammer added that there are small changes individuals can make to use less salt at home, such as shoveling as much as possible before applying salt and refraining from using too much of the product.
According to Hammer's Salt Smart Collaborative, a 12-ounce coffee mug of salt should be enough for 500 square feet of a driveway, or 10 squares of a sidewalk. More resources and tips can be found at saltsmart.org.
• Jenny Whidden is a Report For America corps member covering climate change and the environment for the Daily Herald. To help support her work, click here to make a tax-deductible donation.