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.