Public works crews use different salting methods to clear roads
COLUMBIA, Mo (KMIZ)
Columbia, Jefferson City and Cole County public works crews each have already used up to 2,000 tons of rock salt to treat the roads this winter season.
All departments use rock salt, but every department has a different method of mixing the salt with other additives before it's put on the road.
Jefferson City only uses rock salt and liquid calcium chloride in low temperatures. Rock salt alone is only effective in temperatures higher than 20 degrees. When calcium chloride is applied, salt is more effective in colder temperatures.
"It helps activate the salt, liquefy that salt, which then helps with the melting, but it also lowers the temperature that the salt continues to give you a melt," Operations Division Director of Jefferson City Public Works Britt Smith said.
The City of Columbia uses a rock salt brine mixture with water and beet juice. The sugars in beet juice lower the freezing temperature of snow and also help the salt to stick to the pavement while also being an eco-friendly additive. The liquid brine also allows less salt to be used overall.
"It [beet juice] adds a little bit of stickiness to that rock salt so that, when it hits the pavement, it liquefies, it sticks to the pavement so that when ice forms, it doesn't bind as much with the pavement," Columbia Public Works spokesman John Ogan said.
Cole County uses a combination of methods with crews using different mixes of rock salt, calcium chloride, beet juice and sand, depending on outside temperatures and the type of road. Beet juice is specifically used for icy bridges, while sand is used on gravel roads.
"If we have too much salt on the gravel road, it deteriorates the rock structure of the road and becomes a problem for maintenance," Cole County Public Works Director Eric Landwehr said.
According to the Cary Institute of Ecosystem Studies, the U.S. uses up to 32 million metric tons of road salt per year. The Institute added that runoff from road salt can greatly harm the environment, corrode metal and salinize drinking water.
Landwehr confirmed that this line between public safety and environmental health can be a thin line to walk. Landwehr, as well as Smith and Ogan, confirmed that each department tries to use the least amount of salt possible.
"We found that just because you use more salt, doesn't mean it's going to treat the roads any better, so we try to balance that," Landwehr said. "The environment is something to be concerned about, but it's not shown to be a problem and we're more interested in the safety of the traveling public when these things occur."
Landwehr added that snow plow crews wash their vehicles at car washes where the water is drained into the sewer. Columbia's road salt storage also features a runoff pool where salty runoff sits to evaporate instead of soaking into the ground.
