County to try liquid de-icer

Noting the success Montana Department

of Transportation road crews are having using brine to de-ice state

highways, the Flathead County Commissioners has agreed to follow

MDT’s lead.

In a memorandum of understanding signed

with MDT in November, the county will pay 14 cents on the dollar to

equip two of its 20 plowing and sanding vehicles with saddle tanks

for applying brine, county public works director Dave Prunty

said.

A program intended to reduce dust will

provide the county 86 percent of the $58,000 needed for both

vehicles, he said. The equipment should arrive in August.

But while the initial cost of the

equipment will be sharply reduced, there are other costs, Prunty

noted. The county will pay MDT about 47 cents a gallon for the

brine, which is 20 percent sodium chloride (table salt) with a

corrosion inhibitor added. So with about 1,000 miles of roads to

maintain and a starting application rate of 30-40 gallons per mile,

brine isn’t cheap, he said.

“We’ll apply the brine mostly on hills,

curves and at stop signs,” Prunty said. “That’s all we can afford

to do.”

And then there’s the cost to vehicle

owners. The brine supplier assures the county that the inhibitor

reduces corrosion by 70-80 percent, but the county’s use of the

de-icer “will be good for car wash businesses,” Prunty said. MDT

recommends that owners wash their vehicles regularly throughout the

winter if they drive on treated roads. 

About six years ago, the county tried

using magnesium chloride on its roads, Prunty said, which is

believed to be less corrosive to vehicles than sodium chloride.

The county currently uses a mixture of

90 percent sand and 10 percent salt on icy roads. Much of the sand,

however, gets blown in the wind and contributes to the county’s

dust abatement problems.