Over the past decade or more, liquid salt brine - in place of traditional rock salt - has become more popular with transportation
officials throughout the state for keeping roads from freezing in the winter.
Its use will soon increase in Oneida County.
Highway department head Bruce Stefonek announced the county has been selected as one of 20 to participate in a Wisconsin
Department of Transportation (DOT) pilot program.
The state will supply a $200,000 high-capacity brine-making machine for each county in the program. In return, designated
routes on state highways will become experimental "brine-only" zones.
The word "only" in that phrase is up for amendment, explained DOT maintenance supervisor Anna Wisner.
Brine is only effective to about 8 degrees, although as part of a two-county pilot program last year, Shawano County reported
it to work at temperatures as low as 5.
Beyond that point, counties are free to default to the old-standby use of rock salt, though its usefulness is limited when it
becomes any colder.
"I called it 'brine-mostly'," said Wisner, "If there's conditions like, say, 10 below, the brine's not going to work."
"We don't want to create a safety issue out there, either," she said. "There's flexibility (for county officials) to use judgement
on whether or not to use liquid only or if you're going to go to rock salt ... That's part of the pilot."
She also explained the use of various techniques - like application by high-pressure spray nozzles or the use of chemical
additives - can help push the lower threshold at which the brine is effective.
She said the high-pressure nozzles "can cut through the hard pack or whatever's on the road versus when you apply rock salt,
it melts from the top down."
Wisner said some of the chemical additives may include "B-derivatives, mag(nesium) chloride, and calcium chloride."
Detailed data will be gathered during the pilot program to help steer the DOT's brine policies in the future.
"The UW Tops Lab is going to help us and document what's effective at what temperatures," Wisner said, "and kind of dial in
for us what our most efficient mixes are for different temperature ranges."
Another perk for those counties receiving the new brine-makers is the benefit of being able to use the liquid on its county
roads at no charge from the state.
In addition, counties would be able to sell brine to municipalities within their borders (and theoretically to neighboring counties
without machines) as a revenue stream without returning a cut to the state.
The public works committee is poised to commit to the program, pending approval by corporation counsel of a memo of
understanding (MOU) between the state and the county.
"The end goal is to save money," Wisner said. "Salt is our biggest cost for winter maintenance and we want to reduce the
amount of salt we put on the road."
Among the other effects of brine being tracked, the long-term environmental impact of salted roads is still inconclusive.
Wisner does believe the use of brine is a step in the right direction in terms of reducing that still-unknown impact.
"The benefit is you use less tonnage of salt by 40 to 50 percent," she said. "And you're diluting the salt into the water."
Affects on vehicles
The new medium - and perhaps its adhesive additives - is affecting vehicles in new ways, according to John Pearsall, manager
of Island Collision in Minocqua.
"It's just way, way more corrosive," he said. "Don't get me wrong: it must work for what they want it for, but as far as being
hard on vehicles, it really is. That's what we've seen. I don't know if it's a liquid and it just sprays around more, or if it's
because of what it's made of."
"It's everywhere," he said. "The whole undercarriages and the bodies ... (the corrosion) is quicker than it ever used to be,
Pending approval of the MOU and the county's commitment to the pilot program, the DOT hopes to have the Oneida
brine-maker in place for the next snowfall.