Winter weather poses myriad challenges for road crews in Northwest Montana, but next year crews will have a new weapon to battle the snow and ice.
On Nov. 1, the Flathead County Commission signed a memorandum of understanding with the state Department of Transportation to facilitate the purchase of brine anti-icing solution.
This means trucks can spray the salt water on Flathead County roads before the snow hits, creating a barrier between the chip seal and the precipitation, according to Kyle DeMars, maintenance chief of MDT’s Kalispell division. MDT refers to this as its “just in time tactic.”
The level of separation allows for easier plowing since the snow doesn’t stick to the rock, DeMars said.
Brine solution is just salt and water, DeMars said, which is different from previously used magnesium chloride.
Flathead County Public Works Director Dave Prunty said the county used magnesium chloride years ago, but lately the county’s de-icing and anti-icing methods have consisted of dry materials, such as salted sand.
“We have not done any liquid de-icer for at least four years, and maybe a couple before that,” Prunty said.
Chloride solutions are often used over sand mixtures because sand can be blown off the road and can contribute to air quality concerns, according to MDT.
Prunty said magnesium chloride can be problematic in certain temperatures and situations because it can pull moisture from the air and cause issues on the road even when the weather is clear.
The brine solution does not share this characteristic, he said.
“This stuff can go down pre- and post-storm,” Prunty said. “It doesn’t have the quality of pulling stuff out of the air.”
Both magnesium chloride and the brine solution are corrosives and can adhere to vehicles, Prunty said, but MDT adds a corrosion inhibitor to the mixtures. The brine solution is made at MDT’s Whitefish plant near Highway 40, he said.
The county has a storage capacity of 10,000 gallons for the solution, Prunty said, so when road crews start using it next winter, they will only be using it on intersections and hills to help prevent accidents.
And at 47 cents a gallon, Prunty said the brine solution isn’t cheap, but it is about half of what the county would be paying for magnesium chloride.
DeMars said the salt water mixture has a cut-off temperature of about 20 degrees, but that should not be too much of a problem for county crews.
“If we use it right in the valley, it’s a pretty nice temperature through here,” he said.
Prunty said this new anti-icing tactic would not be possible without a program through MDT that helps pay for new county equipment, such as two combination sanding trucks that can be fit with saddle tanks for the brine solution. The trucks cost about $29,000 each, he said, but MDT covers about 86 percent of the cost through the program.
Flathead County will end up paying roughly $8,000 for both vehicles, he said.
“It’s a screaming deal,” Prunty said. “We’re getting equipment that there’s no way we could afford without this program.”
MDT uses brine solution for highway maintenance throughout the state, DeMars said. It looks to drivers as though the truck is spraying water on the road, but it is actually a highly diluted salt mix, he said.
Since chlorides are corrosives, MDT recommends drivers who use these roads wash their cars regularly through the winter. Tests on the anti-icing solutions used on Montana highways show no negative effects on water quality, vegetation or wildlife, according to MDT.