A Grain of Salt
They just don't make winter roads the way they used to — for which many Maine drivers are grateful. But some vehicle owners fear that in its zeal to keep the state's highways clear, the Maine Department of Transportation (MDOT) is using methods that might have a high cost in the long run.
Several years ago the MDOT began using a new technique to keep the state's winter highways clear of snow and ice. Rather then wait for snow to fall and then plow, the trucks hit the road before the first snowflakes do, applying a rock-salt solution that creates a layer of extremely salty brine on the pavement surface. It is cheaper, faster, and more effective than the old methods of plow and sand. It meets the public's demand for high-speed highways in all but the worst storms. It drastically reduces the department's need to sweep and shovel sand from roadsides in the spring and periodically dig out drainage ditches.
But it comes with a cost. Because the technique uses more salt, complaints about salt contamination of wells have soared in the last fifteen years. Even worse, body shop owners say the salt brine has turned into a corrosion monster that is eating brake lines and sheet metal on cars and trucks all over the state.
It wasn't all that long ago that bare pavement in midwinter was more a wish than a reality. Many Maine residents remember sledding or tobogganing on slick, snow-packed streets and roads. Spreading sand meant a man standing in the back of a dump truck with a shovel. Even ten years ago Route 1 could go for days without showing the center line.
No longer. The goal these days is a snow-free driving environment within two hours after the storm has stopped, according to Brian Burne, a maintenance engineer with the Maine Department of Transportation. In fact, any snow build-up on the road is considered unprofessional. "These days, the philosophy is: If you've got snowpack on the road, you're doing something wrong," he explains.
The change in snow-removal tactics dates back to the late 1990s, Burne says, when the MDOT decided to stop trying to plow snow after it fell in favor of melting some of it the moment it hit the asphalt. "We used to let the snow build up, then plow it and spread traction material [sand and salt]," Burne notes. "When the storm ended, we had to go back over the same highways and deal with the ice that had formed from vehicles driving over the packed snow."
The new approach is called anti-icing. "Up to six hours in advance of a storm, we send trucks out to spray a salt brine on the roads," Burne explains. The brine is made of rock salt dissolved in water — a 23-percent solution, compared to 3.5 percent for seawater — and it dries within forty-five minutes of application. "When snow falls, it wets up" — engineer-speak for the snow melting when it hits the salt — "and forms a brine layer on top of the pavement," he says.
The brine keeps the snow from packing down and freezing to the road surface, Burne explains. As snow continues to fall, trucks spread a mixture of salt and sand that is treated with a wetting agent — salt brine above fifteen degrees or a solution of calcium chloride or magnesium chloride at lower temperatures — that keeps the grit and rock salt from bouncing off the road. The resulting snow and slush can be plowed to the verges much more easily.
On average, the MDOT expects to spread thirteen tons of salt per lane mile over the winter. (A "lane mile" is one mile of one lane; a mile of two-lane highway equals two lane miles.) "On the Interstate it might run a little higher, fifteen tons per lane mile," Burne explains. "In all, we're responsible for 8,300 lane miles of highway."
The method has its attractions. For one, it's cheaper. The MDOT used to go through half a million cubic yards of sand every winter in the 1990s. Now it uses only fifty thousand cubic yards, and much of that is in the mountains of western Maine. And using less sand means the MDOT doesn't spend as much to sweep it up in the spring. Burne says the department saved upwards of three hundred thousand dollars in its southern Maine district in spring-cleaning expenses alone. Salt use is up, of course, from around 75,000 tons in the 1990s to more than 100,000 tons now, at a cost of $5 million to $5.6 million this year.
But using more salt worsens environmental problems, especially groundwater contamination. Fifteen years ago, for example, the department's environmental office fielded ten to fifteen complaints a year about salt contamination of wells. These days the MDOT receives upwards of fifty or more each year, according to Dwight Doughty, chief of the environmental bureau.
He makes a point of noting that MDOT trucks use the latest technology to calibrate the precise amount of salt to use each time they hit the roads. "But one of the unfortunate impacts is on water supplies," he admits. He says the number of complaints has been "pretty consistent" over the past five years.
Doughty attributes the complaints to "a combination of anti-icing and getting the word out that someone who has an issue with well contamination should give us a call. State law requires us to remedy any adverse impacts, and we have a team dedicated to well claims." Additionally, salt has been implicated in damaging roadside plants and trees, as well as having an impact on nearby vernal pools during the spring runoff.
Despite the problems, the new method is seen as meeting the driving public's increasing demand for better road conditions in bad weather. Burne acknowledges that "the public certainly does play a role" in the department's push for ever-more-aggressive snow removal strategies. "We have more traffic on the roads every year, more demand for the ability to go faster," he explains. And less snow on the roads means safer roads, although no one has done specific research on accident rates to prove the suspicion that there are fewer highway crashes attributable to slippery roads today.
But some Mainers suspect that the war against snow and ice carries a hidden cost, one they're seeing in corroded brake lines and rusty rocker panels. "I started seeing it about two years ago," reports Dan Vaillancourt of Smart's Body Shop in Bath. "There's a lot more corrosion than what I saw previously."
"We've had cars in here that are a year old and found rust inside the body panels and door posts," reports Bill Sanderson, who oversees the body shop at Shepard Motors in Rockland. "You never saw that before. And brake lines are rusting through after three years."
Sanderson, 59, has spent a lifetime in the car business, and he can't recall a similar situation. "We had a Chrysler Cirrus in here that was five years old, less than forty thousand miles on it, and both rocker panels were totally rotted out," he recalls. "It was a six thousand dollar job to fix it."
"Look at cars on the Interstate; they're snow white with salt," points out Sid Bubar, of Butler's Auto Body in Hampden. "You know the underside of the car is going to look even worse."
Both Sanderson and Bubar say the salt brine that keeps roads from icing also splashes and sprays off the wheels and penetrates every tiny nook and cranny. "That liquid gets into the pinch wells, the point where panels come together and are welded," Bubar explains. "It doesn't take much to get rust started — a little ding from a rock kicked up from a tire or just normal wear and tear."
Brake and fuel lines, which run along the frame under a vehicle, seem to be special targets. "Under the new vehicle inspection rules that went into effect in December, you can't have rusty fuel or brake lines," Sanderson explains. "It used to be a judgment call, but now there's no room for that."
The MDOT's Burne has heard the complaints, but he's not convinced they are as serious as some people think. "I'm not denying chloride accelerates the corrosion process," he allows. "But it's not the calcium chloride that's rusting cars, as many people seem to think. First, we use corrosion inhibitors in it. Second, we don't use that much of it — eight to ten gallons per ton of salt as a wetting agent."
The salt brine today "uses the same salt we used in the old days, plain rock salt," he adds. "I think it tends to get sprayed around a lot more, though." While Burne admits he has fielded calls from mechanics "asking me why they're seeing a lot of rusted brake lines," he counters that he has never had to replace a brake line on his own cars, despite driving them well past the hundred thousand-mile mark.
"I think we're seeing older cars having this problem, and manufacturers who are using cheap brake lines," he offers.
Bubar agrees that older cars are vulnerable, possibly because they've been exposed to the salt longer. "We're really seeing the effects in cars more than five years old," he reports. "Just recently I've seen a couple of Caravans and a Taurus that had panels rusted out."
But in Bubar's view that just makes the problem more insidious. "People who have enough money to trade in their cars every couple of years, they're not going to be bothered by this," he points out. "It's the poor people who are being hurt. Someone with a seven-year loan on a used car is out of luck if the body panels start rusting through after two or three years or the brake lines need replacing."
Washing cars more frequently, especially in commercial carwashes that spray the underside of a vehicle, can ease but not totally eliminate the problem. "It's pretty hard for most people to wash the underside of a car themselves," adds Vaillancourt. "Even in a carwash it doesn't work that well."
"You're trying to wash off hours and days of salt buildup with a few minutes in a car wash," notes Sanderson. "You can't get the water up into all the places you need to. With the old salt and sand mix, it was solid and didn't stick much to begin with. Even when it did build up, you could knock it off pretty easily."
Salt isn't the perfect solution; it's just the best one. There are no alternatives if public expectations are to be met. "I suppose this is the best of two evils," Sanderson muses. "You can have the salt or you can have the snow."
"People drove differently years ago," recalls Bubar. "No one thought about driving fifty-five miles an hour down the highway. But we got where we needed to go. We put the tire chains on and drove a lot slower."
"I can remember when Route 1 would be covered with packed snow for a week or two at a time," adds Sanderson. "We drove slower and more carefully. Now people buy an SUV with all-wheel-drive and traction lock and antilock brakes, and it gives them a false sense of security. They think they can drive the speed limit or better in any weather, and when they go off the road in a snowstorm they blame the highway department instead of themselves."
Even the MDOT's Doughty, who grew up on a dead-end road in rural Cumberland before it became a suburb of Portland, remembers a different philosophy toward winter driving. "When I was a kid, we knew we weren't going anywhere for a while when we had a bad storm," he recalls.
In a way, the MDOT has been a victim of its own success, he says. "We've gotten so much better at improving the maintenance of our roads, and folks have become accustomed to it," he points out. "Going back to the old ways is not an option."