When snow arrived Saturday night for the first time this winter, 90 plows were ready to keep Needham’s roads open: 28 routes planned, drivers briefed, salt loaded, tanks of brine at the requisite 23.3% salinity. After reviewing the information board, the weather forecast, and temperature data of not only the air but also the pavement, Assistant Director of Public Works Shane Mark gave the signal and plow drivers headed for the routes they would follow for the next 24 hours or so.
At the snow removal command center housed in the aging, 1960s Department of Public Works building, magnetic tiles on a white board represent each of the plows and their information. When a truck stops for any reason — mechanical problems, frozen hydraulics, driver rest stop — the driver calls the command center and the marker for that route is turned sideways until plowing resumes.
“We get a team together, so we have our highway director, assistant director, public works director and me,” said Mark. “We’re talking frequently the day before the storm and during the storm about the overall operations. As we’re looking towards the end of the storm, we’re projecting out how long it will take us once the storm ends and planning those staffing levels.”
Having arrived in Needham just over a year ago, Mark is relatively new to Needham’s DPW, but he has spent a significant amount of time and attention preparing for the town’s snow events. His first job out of college involved deicing air-freight planes. When he went into municipal street maintenance, which involved getting a master’s degree, and rose through the management ranks in Columbus, Ohio, and then Newton, he began attending the annual snow conference held by the American Public Works Association. He now sits on the subcommittee for snow and ice operations.
“Snow removal is art and science,” he said. “The art is finessing the plow. Our goal is to get as close to the curb line as possible. We want to widen that road out and open up the catch basins to allow melting snow to drain. The second reason for plowing curb to curb is you always want to create storage space for future storms. If we get a season where we’re seeing back-to-back storms, we want to make sure that we have enough storage space for our snow so that our streets don’t go down to one lane.”
The science is largely about making sure the roads have good traction without oversalting them or using some of the more environmentally damaging techniques. Salts, said Mark, only work when they are saturated. On hard ice they work very slowly, but dilute them in water to create a brine, and they hit the ground running, so to speak. Needham is slowly expanding its brining capabilities to improve road quality and reduce overall salt use, lessening the negative impact that salt has on the environment.
Brine is widely used in the Midwest, but rarely in Massachusetts. Mark and other professionals seek to change that. “For the last four years we’ve been touring the commonwealth and training snow and ice professionals on the advantages of brine – what conditions you should use it, what conditions you shouldn’t use it. And so what we’ve really seen through this training over the last four to five years is that a lot of municipalities are now embracing the liquids application.”
The real effect of salting is to break the molecular bond between the ice and the roadway, Mark said. That’s why DPW teams check pavement temperature with infrared thermometers similar to those some doctors use to scan patients’ foreheads. Colder pavement means a stronger bond. “The purpose of the salt is to break the bond or delay the bond of the snow and ice so that we can use the plows to push it off the roadway,” Mark said. “The brine leaves a thin layer of salt crystals that begin to melt the snow as it falls — deicing from the bottom up.” Ultimately, the team is looking for good grip and friction (called grip index), which is the standard that airports use when plowing runways. “New technology can provide a grip index as well as pavement temperature. It’s amazing. It’s exciting to be part of it.”
Even the town’s ever more sophisticated approach does not make everyone happy, though. Homeowners are frustrated when plows leave a new line of snow at the end of cleared driveways. And the sidewalk-clearing equipment occasionally tears up lawns. “We get those complaints and come back and put loam and seed out in the spring,” Mark said. “It doesn’t make sense to do it after each storm — we may turf that lawn again in the next storm.”
The pattern of warmer winters makes for more of that lawn work because the ground under the snow is still soft, Mark said. Warmer winters have also made it harder to find contractors to plow. The contractors who own fleets of dump trucks are able to use their trucks for landscaping and building projects through the winter months rather than outfitting them as plows for occasional use. While there was a full fleet ready for the weekend storm, many of the contract trucks were smaller pickups rather than large dump trucks.
“I would just say to our residents, try to be patient with us,” said Mark. “These long-duration events are tough to manage. You know, 6 inches over the course of 17, 18 hours is tough. Our operators have been up all night long. We plow each street multiple times, so you may have to clear your driveway apron several times. So just try to be patient with our operators.”