Anyone who travels Wichita’s main roads during the ice and snow season might notice that the city has laid down ribbons of whitish material onto the pavement.
It’s called brine, a mixture of pure salt and drinking water, according to Alan King, the city’s director of public works and utilities.
“So it’s really, really safe stuff,” King said.
The salt comes from the Hutchinson salt mines, and the city is fortunate that the source is so close, King said. The salt gets mixed with drinking water so that the salt makes up 23 percent of the concentration. Any higher percentage, and the salt wouldn’t dissolve. The 23 percent level works on ice when the temperature gets as low as 12 degrees, or 20 degrees below the freeze point. Below 12 degrees, even salt can’t cut the ice.
Rust a downside
The bad thing is that while the salt dissolves ice and helps keep people safe and roads passable, it corrodes cars. Every year, King hears motorists’ complaints about that downside.
“Now, it does rust cars,” King conceded Friday.
“I got a car, and I don’t like it either, but I would prefer that to driving in unsafe, icy conditions,” he said. “It’s a tradeoff.”
One mitigating factor, King said, is that newer cars have more protective coatings. But even with extra layers, as a car rolls over wet streets, the vapor sprays brine “into every crook and cranny, and it sits there,” eating into the metal, said Kurt Fowler, co-owner and service manager at Autotech, near Central and West Street. Each time the trapped brine gets wet, it starts chewing again.
A related problem is that the sand that also is used to treat roads chips away at coatings, exposing unprotected spots to salt’s corrosive effect, Fowler said.
He recommends regular rinsing of the surfaces you can see as well as a thorough “belly-washing” in the spring – to get underneath a vehicle and scour the crevices where the brine hides and wears into the metal. Some commercial car washes have sprayers that clean underneath a vehicle.
Fowler also is a vintage-car specialist and active member of the Central Plains Region Cadillac LaSalle Club. Rust is the club members’ bitter enemy. When the brine is out, they keep their lacquered and chromed cars in, away from the dampness and corrosion.
For all his love of cars, Fowler said, he agrees with King that salt and sand is “a tradeoff we have to accept” for safe transit.
Fowler called the city’s use of salt and sand “the very best combination” for battling road ice.
A preemptive strike
City crews put down just enough brine to do the job and help control the cost, King said. The price basically amounts to the cost of the salt used to mix with water, so the “material cost” is 5 cents a gallon, said Joseph Pajor, deputy director of the city’s Department of Public Works and Utilities. The city uses its own brine-mixing facilities.
The city has been using the same brine recipe for years, King said.
In the war on ice, the city’s strategy is to be preemptive in its brine strike, King said, so the brine gets deployed with nozzles before the ice and snow parachutes in. That way, the brine is ready to melt the enemy when it hits the pavement.
The brine has to go a long way. It gets applied onto 1,500 “lane-miles” of priority routes, out of a total of 5,000 paved lane-miles in the city, King said.
After crews apply brine to the streets, they use a 50/50 mix of pure, dry salt and sand to further treat the roads. The sand comes from sand pits.
When it rains, some of the brine will wash into the waterways, but King said the effect is negligible. The city, he said, has never been found to have violated its state permit regulating the quality of water that runs off the streets and into creeks and rivers after a rain.
In King’s dream world, there would be no need for brine.
“If I had my preference,” he said, “it would be 80 degrees all year.”
Reach Tim Potter at 316-268-6684 or firstname.lastname@example.org.