CLAREMONT — If you are walking down Pleasant Street this winter and the brownish slush in the road suddenly makes you crave gingerbread cookies, don’t worry. There is molasses in the road treatment now.
According to Jeremy Clay, assistant director of the city’s Department of Public Works, Claremont road crews are using a new type of road treatment this winter, which may prove more effective, efficient and less corrosive than traditional rock salt.
Pre-treated rock salt is a liquid sodium chloride of salt brine, which according to Clay is the condition that solid rock salt particles become once dissolved in the road.
“Rock salt [in solid form] doesn’t melt the ice,” Clay explained. “It’s the brine it creates after dissolving in water that melts the ice.”
There are numerous advantages to using pre-treated rock salt, according to Clay. For starters, the brine of pre-treated rock salt remains effective as colder temperatures, as low as 8 degrees Fahrenheit, as opposed to untreated salt brine which loses effectiveness at 20 degrees Fahrenheit. In some cases with untreated rock salt, the brine solution becomes too diluted and refreezes.
“Then you’ve made an ice skating rink,” Clay said.
Another problem with untreated salt crystals is their penchant to “bounce and scatter” when hitting the road, winding up off the road or down storm drains.
Pre-treated salt is an “anti-icer,” rather than a “de-icer,” according to Clay. In anti-icing, the crews lay the solution to the roads before snow falls and ice forms in the roadway. The brine melts the snow or ice from underneath.
A key additive to this formula is molasses. The molasses acts as a stabilizer, a substance that binds the salt and the water to prevent the solution from separating. The substance sticks together in clumps when applied to the street. This allows road crews to lay it evenly and in a line.
Clay said the strategy is for road crews to apply the substance to the path that the vehicle tires will follow. The tires of the passing vehicles push the substance outward to new areas, where the substance continues to melt.
Since the substance is already in brine form, it begins to melt quickly, according to Clay.
“We used it in the last storm [on Dec. 2 and 3] and I liked how well it worked,” Clay said.
Purchasing the solution already treated is expensive, approximately $92 per ton, as opposed to $62 per ton for untreated rock salt, according to Clay. To lower the cost, the department purchased two 150-gallon tanks and attached each to a plow truck. These tanks hold the molasses solution, which is mixed into the untreated rock salt before being applied to the road. Clay said this was the most cost-effective solution.
The other advantage of molasses is that it is found to be less corrosive to vehicles than salt. Clay hopes that reducing the amount of corrosive agent in the treatment will have additional cost savings for the department, with less repairs to their vehicle fleet, better resale condition and possibly a life extension.
One lingering concern with using a molasses based treatment could be the attraction of deer to the roads.
Clay has asked the Claremont Fire Department to log the number of vehicle collisions with deer this winter to study whether the treatment is attracting animals. When snow accumulates and covers food sources, deer may gravitate toward roads and the fragrant molasses. With a relatively new product, the potential impact on wildlife is still being studied, according to Clay.
“The molasses smell is strong, like cookies in the oven at grandma’s house,” Clay said.
The pre-treated salt leaves a brown residue. Clay said in Vermont where it is used, the residue is green, per the request of the governor. The Claremont Department of Public Works opted against applying the pre-treated rock salt to sidewalks in the downtown commercial district because business owners might not want customers bringing a brown residue into their stores or offices.
The city is applying the solution on sidewalks near schools, such as Maple Avenue Elementary, because there is enough ground between the sidewalk and the school building for the residue to come off students’ boots.