Road salt, for better or worse is back this winter

in Environment/Infrastructure/Transportation

Salt on the roads has becomes a fact of life in New England during the snowy months from November to April, but that was not always so.

In 2007, the State of Connecticut changed from a sand-salt combination to the exclusive use of salt on state roads, according to Kevin Nursick, spokesman for the Connecticut Department of Transportation, in a November 21 phone conversation.

“Salt has its own problems, it’s just less problematic than sand,” said Nursick, who has been with the DOT for about 15 years. “It’s more effective at melting frozen material on the roadways and so it improves road conditions. It is environmentally superior to sand-salt mixture, but it’s not perfect.” 

Sand picks up road contaminants and is effective in carrying them into water courses, he said, adding that it’s expensive to sweep the contaminated sand off the roads and dispose of it properly. 

“Road sand carries those contaminants into waterways and also causes turbidity and sedimentation in waterways, so it has more negative ramifications than just using salt alone,” he said. “At the end of the winter season we had to go and sweep all of the roads to the tune of probably $5 million a year. And then it can’t just be dumped anywhere, it needs to be disposed of because it’s considered hazardous material — fewer and fewer locations will take it.”

In 2018-2019 season, the state used 172,958 tons of salt on its 10,800 lane miles of state roadways. Nursick said the state has $38 million set aside for snow-fighting this year and about $10 million will be for salt. For the last three seasons, the state has paid about $60 per ton for salt — it’s been as high as $76 per ton and as low as $53 per ton since 2007. 

“Salt is cheaper than sand because you don’t have to clean up salt,” he said. “Salt has its problems but it’s the only cost-effective road treatment that is really available to winter weather states.”

With 634 plow trucks statewide, the DOT applies about 200 pounds of salt per lane mile, he said. 

The DOT has a total of 88 salt sheds stationed all around the state, “where our crews can go and load up for snowstorms,” Nursick said.

“All of our salt sheds are modern — they’re kind of a sarcophagus … with concrete foundations and it’s not permeable. The salt doesn’t get wet so nothing is permeated into the ground from there, it’s all contained, and that’s part of being responsible about using salt sheds,” he said.

Environmental impacts

The state treats its rock salt with liquid magnesium chloride and many towns buy salt pretreated with chloride. Rock salt is effective to about 25 degrees and then its efficacious starts to drop off. The addition of chlorides keeps the salt working as temperatures drop, said Nursick. 

The majority impact is the salinity in the inner water bodies and the well water impacts, he said. 

“We are very prudent about how we use chlorides, understanding there are ramifications. We’re not over-applying where it doesn’t need to be. We’re as responsible as possible about it,” he said. 

Other products can do as good a job as salt but cost three times as much or more, he said. “There are exotics out there if you’re willing to substantially escalate your snow budget.” 

Nursick said the DOT was working to produce the best road conditions with the least amount of chloride, at the same time hoping an affordable solution will come forth that works as well as salt with lower environmental ramifications.

“Ultimately there’s going to come a day when we’re going to get there because there are ramifications for using these things and they will build up in the environment,” he said. 

Strategic pretreating

Nursick said the state uses a special “brine” of 73 percent water and 23 percent salt to pretreat specific problematic areas, such as the Gold Star Bridge, before a storm. 

“It’s probably 300 lane miles total when you add up all the bridge surface areas and other locations — the hills and valleys, what we call microclimate areas — that we know tend to be more conducive to bad conditions,” he said. 

When the brine is sprayed on the roadway, the liquid evaporates and that leaves fine salt crystals in the nooks and crannies of the asphalt semi-bonded to the road surface, which will lie there undisturbed by motor traffic, in theory up to a week, until a climate condition such as snow activates the salt and it starts to work, Nursick said. 

“It’s the same thing if there’s an icing condition or a frosting condition, say on the Gold Star, and when the conditions become ripe for a freeze-up the salt starts to work and prevents the freeze-up,” he said. “The salt helps keep the snow from binding to that bridge surface so it helps us get down to bare asphalt sooner.”

The process is “basically an all-day operation” because the pretreating trucks do one lane in one direction, get off at an exit and go in the other direction and do the next lane — making big loops to cover the designated area, Nursick said. 

Spraying dry rock salt on a highway is not effective because high-speed traffic blows the salt off the roadway. Towns with lower traffic volumes can spray dry rock salt on roads and the salt will mostly stay put, he said. 

Pretreating prevents accidents, Nursick said, referring to a 2015 report by the Connecticut Academy of Science and Engineering that compared CT DOT data on the number of snow, slush or ice crashes from 1999 to 2006 and from 2006 to 2013 in the months from November through April. In 1999 to 2006, deemed the “deicing years,” the state used a sand-salt combination and there were 7,324 crashes with injuries. In 2006-2013, the “anti-icing years,” the state used salt exclusively and there were 4,875 crashes with injuries, or 2,449 fewer crashes than the sand-salt years. 

Salt coming ashore

When salt is unloaded at State Pier, most of the time it’s on a full ship holding about 45,000 metric tons of salt, or 49,600 U.S. tons, said Gilles Plante, Operations Manager of Gateway Terminal at State Pier. 

The ship’s salt, originating in places such as Egypt or Chile, is loaded onto trucks that can hold 20 tons each, said Plante. Over a period of five or six days it takes 2,500 trucks to haul all of the salt to the large, tall salt pile — owned by DRVN of Rocky Hill — that is protected by weighted tarps.

Plante said when a shipment comes in, the terminal’s crew work to protect all of the equipment on the pier, especially on windy days. 

“When we have a ship coming in and we have to use the main dock, there’s a lot of other materials we have to protect because it belongs to our other customers so we tarp it while we unload the ship,” he said. “The salt is not the best commodity to have close by — with salt you really have to be careful — it’s corrosive.” 

Two towns’ experiences 

Stonington puts out about 125 to 150 tons of salt during a typical storm on the town’s 117 miles of roads, according to Tom Curioso, highway supervisor. 

“We do stockpile here — our salt barn holds between 600 and 700 tons of salt and we use a treated road salt, it’s a product by Morton Salt called Ice B’ Gone,” he said, adding that the town is paying $65.87 a ton this year for salt compared to $73 per ton last year. 

The town buys its salt through the Capitol Region Council of Governments, which provides a discount, said Curioso. The town uses about 2,000 tons of salt per season, which is part of the town’s annual municipal budget for snow removal.

Pretreatment is done with the “dry” method — not using brine — “but only if we know there’s a predicted and probable storm,” said Curioso. 

“This year I feel well-prepared because we’ve had enough time and we start to prepare in the fall, of course we never know how many storms, so that’s the problem,” he said. “And it’s New England and it’s a coastal community here. If you go a few miles north up near I-95 they can six inches of snow and when you get to the coast it might be two inches so it can vary that much.” 

In East Lyme, Director of Public Works Joseph Bragaw said the town built a new salt dome about four years ago that can accommodate up to a year’s supply of salt. 

“We have about 1,200 tons on hand. Our typical winter is about 2,000 tons,” he said. “As the storms start rolling in, we might get 200 or 300 more tons at a time.”

Like Stonington, East Lyme purchases its salt through the Capitol Region Council of Governments

“Our salt comes out of the Gateway Terminal in New Haven. It’s about $70 a ton… so about $140,000 for the year. The rest of the money in our account is for plow blades, repair to plows, extra equipment for snow operations,” he said, adding that funding for the town’s salt is not affected by the state’s Town Aid Road bond because the town has a budget line item for salt and storm materials. 

Bragaw said the town averages about 60 inches of snow per winter and only received 14 inches last year, but his crew was still taking care of the roads to prevent ice formation. 

“Even though we only had 14 inches last year, you still have to go out all those times where there’s no snow, black ice, all that stuff. Typically you’re going to go out 15 or 20 times a year,” he said. “People forget about all the times that they wake up in the morning and it was raining the night before and it was a deep freeze. They wake up in the morning and everyone drives off to work and everyone’s happy but we were out since two in the morning applying salt to 114 miles of roads so that the ice didn’t formulate.”

He said even if there is no accumulation of snow, “there’s plenty of times we go out … and it’s not a snow day for all the students — we get them to school because we’re putting salt on the roads to take care of the ice.” 

Public expectations 

Over time the public has become more demanding in terms of the level of service from the DOT during and after snowstorms, Nursick said. 

“From our point of view the public is expecting higher and higher levels of service during winter weather with every passing season,” he said. “There seems to be a higher level of service expectations during and immediately after winter weather storms. The bottom line is people want to go faster and drive just like conditions are normal in winter weather storms and right afterwards and they are expecting us to achieve that level of road conditions so that they can do that.”

Safety on the roadways fundamentally relies on motorist adjusting their driver behavior during winter weather as opposed to how spotless the DOT can have the roadways in the winter, he said. 

“Road conditions are never going to be good during winter weather storms and we need the public to understand that. As we have refined and made more efficiencies in our technologies and application methods, we have definitely gotten better at making the roads and better driving conditions but we’re never going to get to that point where [we’re] going to get to these hyper-ideal conditions during a storm — that’s just not going to be the case,” he said. 

He said it takes about two hours on average for one truck to make a complete loop during a storm — that’s two hours of accumulation between passes, he said. 

When the state switched from sand-salt to exclusively salt, it was an instant change in road conditions, Nursick said. 

“Long gone are the days where 24 hours after a storm you’d have snowpack on the roadway or on a bridge,” he said. “Because the materials that we were using weren’t actually removing the frozen material to get us back down to bare pavement — you had to go out there with a jackhammer to get rid of it. The salt priority has virtually eliminated that type of scenario. There’s a much higher level of expectations on the part of motorists that they’re not going to hit those conditions.” 

Winter driving requires a “change in mindset,” he said. “The driver mentality is super-important when it comes to safety, to get drivers to change over to that winter weather mode.”

The biggest user

With about 35,000 lane miles compared to the DOT’s 10,800 lane miles, Connecticut’s 169 cities and towns are using more salt than the DOT, Nursick said. 

But, the biggest salt user is the private sector because of the fear of “slip and fall” lawsuits, said Nursick. 

“They are overapplying to try to reach an unattainable goal of protecting themselves from litigation,” he said. 

He said the biggest environmental concern is also the private sector. 

“In part it’s private individuals but mostly the commercial private sector — contractors taking care of retail parking lots and business facilities. You can see parking lots that are bright white with salt,” he said.  

Looking for balance

Nursick said salt is a compromise — the best available balance of cost, environmental impact and efficacy. 

“It’s not perfect, it’s not a silver bullet,” he said. “A majority of towns are using salt… it’s the standard bearer now, it’s the go-to material because there is nothing more effective for getting the mission accomplished with lower environmental impact… and it’s affordable.”

But he continues to look for alternatives that will check the important boxes and keep the roads open and safe. 

“If someone has something better, we’re all ears but until then there’s an expectation that we’re going to get out there and do something when it snows and we’re going to do our best and use the best balance that we can strike and that’s with salt,” he said. “There’s a lot going on behind the scenes, other little technologies like brine-making machines and stuff, but it all goes back to salt, salt, salt.”