Andover DPW Using Salt Brine as Pretreatment for Roads to Reduce Ice Buildup, Environmental Damage and Costs

Trucks are lined up inside the Andover Department of Public Works garage, where workers are preparing for winter snow with help from a new technology: salt brine. Salt brine bonds to asphalt, making it more effective than regular rock salt, and yet also less expensive for the town and better for local water supplies and lawns. (Photo Courtesy Andover Department of Public Works)

ANDOVER — Town Manager Andrew Flanagan and Department of Public Works Director Christopher Cronin would like to inform the community that the Andover DPW will be spraying liquid salt brine on town roads this winter before snowstorms.

Salt brine is a precisely calibrated mixture of water and rock salt that will be sprayed on roadways up to 24 hours before some winter storms in order to reduce ice buildup and to reduce the effort required to clear away ice that does form.

Using salt brine instead of traditional rock salt saves taxpayer dollars because far less rock salt is needed. Rock salt costs between $62 and $65 per ton — with those costs expected to rise. Pretreating Andover’s roads with rock salt requires about 49 tons of rock salt, whereas only 18 to 22 tons of rock salt are needed to make enough salt brine to pretreat the entire town before each storm.

Salt brine is also far better for the environment since it requires a lower volume of rock salt to pretreat roads, resulting in less salt making its way into local water supplies, where it is a significant pollutant.

Salt brine will also reduce damage to lawns in town, which can be harmed when rock salt is blown or brushed off of roadways and into grass. Salt brine bonds to roads and leads to far less salt ending up on lawns.

Salt brine’s ability to bond to the roadway also means DPW crews can pretreat roads far earlier than they can with rock salt, which tends to get blown or brushed off busy roads by traffic. Rock salt must be applied as a pretreatment as close as possible to the time when snow starts falling, whereas salt brine can be applied up to 24 hours before a storm while still being effective.

“Using salt brine as a pretreatment is not only a more effective and flexible method of preventing ice from forming and bonding to local roads, it also saves taxpayer dollars by reducing the amount of raw materials needed for each storm and limits environmental damage,” said Director Cronin. “It may seem counterintuitive that spraying a liquid on roads before a storm will help stop ice, but salt brine provides proven results while also providing important benefits compared to more traditional pretreatments.”

The brine is mixed in specialized equipment purchased by the Town and located at the DPW, which can prepare up to 6,000 gallons of the mixture in an hour and then store it in two large tanks in anticipation of storms. The mixture is then sprayed on roadways by DPW trucks using specialized tanks and sprayers that can be attached to both traditional snow plows or smaller vehicles like heavy duty pickup trucks.

Salt brine will not replace the DPW’s traditional methods of clearing snow after storms, or change the way roads are treated once snow has fallen, as traditional rock salt is still the most effective treatment once snow is on the ground.

Salt brine will also not replace treatments used at particularly low temperatures — below 10 degrees Fahrenheit — because at those temperatures treatments like calcium chloride remain more effective.

“We are excited to bring this new technology to bear to reduce costs, help the environment, and to provide our crews with more flexibility before storms. The Andover Department of Public Works is fully committed to using only the most effective methods of treating town roads,” said Director Cronin. “We hope everyone stays safe and drives responsibly this winter as we once again face a New England winter together.”

To view a video on the use of salt brine that was prepared by Andover TV, click here.