Molasses and beet juice. And lots of salt.
Keeping the roads and streets from becoming slick ribbons of ice takes more than loading up the trucks with sand and salt as the snow begins to fall. Pretreating is the thing now, and what you put down then depends on what will be coming down later — and how low the temperature will go.
Tom Hunt, highway foreman for the Milford Department of Public Works, has learned from his colleagues in Fairfield, North Branford and upstate New York. He’s found that a mixture of molasses and rock salt, when put down in really cold weather, will melt ice really well and keep melting it for six hours. The sugar in the molasses lowers the ice’s freezing temperature.
“There’s a very interesting story behind it,” Hunt said. “In the Great Lakes there was a brewery and the DEP allowed them to dump molasses in the lake during the winter months.” People noticed that while the lake iced over, the area where the molasses was dumped didn’t freeze.
The molasses actually comes from the leftover mash used in distilling rum and vodka, Hunt said. Mixed with magnesium chloride and marketed as Ice B’ Gone Magic, it has other benefits besides being a good ice melter.
“You’re using less salt and you’re using more of the leftover rum and the vodka and the mash itself,” Hunt said. Also, “it saves on cleanup,” because Hunt doesn’t have to use sand. That helps during the winter and also in the spring, when sand clogs up the catch basins.
It also requires his city workers to drive for fewer hours, saving on the budget. “Plowing snow is blood money,” Hunt said. “You’re out and you’re doing 16 hours behind that wheel. … It takes a certain individual to do this job.”
Something else about Ice B’ Gone Magic: Dogs love it. “You’ll see them lap it up on the side of the road sometimes,” Hunt said. Deer like it, too.
When he pretreats Milford’s 282 miles of roads (including private streets but not state roads), Hunt will let it sit before he starts plowing. “I’ll leave the material knowing that I’m going to get ice soon, so I’ll let it sit on the road until the temperature rises. Then we’ll clear.”
The amount of material Hunt has his drivers put down depends on how much snow he’s expecting. They’ll drop 200 pounds per lane mile for 1 to 2 inches, 300 pounds for up to 8 inches. “If I know I’m going to get walloped and get a foot, sometimes I’ll put 400,” he said.
The drivers have electronic controls in their cabs with which they can adjust the amount of material that’s spread on the roads and gauges on the truck that take the temperature of the air and the roadway as they go.
Another material Hunt uses is a mixture of brine, magnesium chloride and calcium chloride. “This is a liquid salt paste,” he said. “Upstate New York has been using it. It’s more effective [than brine alone] and I can use it two days to three days prior to a storm.” Because it’s a paste, it sticks to the ground.
The paste is best used in higher temperatures, he said, and trucks have alarms to warn them if they go too fast. “You can’t go over 20 mph because you want it to be real thick,” Hunt said.
Hunt said he stays with brine rather than rock salt as a defensive measure. “There’s always an overabundance of liquid vs. there’s always a shortage of salt,” he said. The state Department of Transportation “overrules us” if there’s not enough salt to go around, so Hunt would be left short if he stuck to rock salt, he said.
In New Haven, Rick Fontana, director of emergency services, said the Public Works Department, under Jeff Pescosolido, uses beet juice to supplement its salt. “The reason why we’ve actually stocked up on the use of beet juice is a couple of things,” Fontana said. “Number one, it’s more friendly to the environment,” doesn’t hurt trees when it gets sprayed onto them and doesn’t corrode cars.
Also, “you can use it down into the teens. It can melt ice and hard snow formations.” The disadvantage of beet juice, though, is that it’s expensive. So salt and a combination of salt and sand are more commonly used.
The DOT pretreats about 300 lane miles with brine, consisting of 77 percent water and 23 percent salt, according to agency spokesman Kevin Nursick.
That’s less than 3 percent of the 10,800 lane miles of state and federal roads the DOT has responsibility for, including the interstate highways, and includes bridges, hills, valleys, some on-ramps and off-ramps and certain micro-climate areas that are known to freeze more than most.
“Salt is not great for the environment but it’s better than what we were previously using, which was a sand/salt mixture,” Nursick said. The switch to the brine was made in 2007.
“Salt is not perfect [but] it is the only product currently available that is mission-effective and cost-effective,” he said.
Typical salt, sodium chloride, breaks down when temperatures go below freezing, so the state also uses liquid magnesium chloride when temperatures drop, but, Nursick said, “We’re very judicious about our use of chlorides here,” he said. “We use rock salt and when conditions warrant we add liquid magnesium chloride. We make sure our equipment is calibrated appropriately … enough to do the job but not more.”
The state also has 39 roadway weather information stations that “provide real-time data to the DOT for proactive and reactive measures, to address weather threats,” Nursick said.
The stations measure air and road surface and subsurface temperatures, humidity, dew point, barometric pressure, wind speed and direction, the rate and type of precipitation and the pavement condition, including the amount of salinity on the road, Nursick said. They are also equipped with cameras.
“We can use all of this data to address real-time conditions and to give us trending information, too,” he said.