Behind the Scenes at DPW: "It's Not The Inches, It's the Ice"

The presentation on winter operations held in the "war room" at Norwalk DPW headquarters at 15 South Smith Street was the Mayor's idea.

Rilling rode along in a plow truck at 6:30a.m. during the recent Hercules storm and was impressed enough with the process he described as sophisticated both in terms of science and skill that he thought citizens would want to know more.

And so, on Wednesday, DPW Superintendent Chris Torre and Operations Manager Lisa Burns showed off the up-to-date fleet from the operations center catwalk, followed by a talk given in the war room. 

Gone are the days that employees spent August chipping the rust off the vehicles, Burns joked, adding that DPW has invested heavily in its fleet, which has brought down maintenance costs.  

And DPW doesn't just use classic snow plows, but rather utilizes different types of vehicle for different purposes. 

"It's not the inches. It's the ice," said Torre, explaining that freezing rain and wintry mixes bring out the fleet far more often than accumulations of snowfall. So, while the citizenry may count two significant snowfalls so far this winter, by DPW's count, they're up to seven, and anticipate between 10-15 on average for the year.

Torre and Burns took guests to from the "war room" to the "catwalk" at DPW Operations Center for a good view of the fleet.

"We have 35 trucks and a ten-year fleet replacement program," Burns said. "So we rotate three trucks in, and three trucks out every year. It's in the budget. We had a really old fleet when Hal and I both started," she said, referring to Hal Alvord the DPW director. "That impacted our ability to do snow removal."

"All our plow trucks are either Sterling or Mack trucks," said Torre of the investment in the fleet.

"We budget for 6,000 tons of salt for a total of a half million dollars for the year," Burns added, before delving into the science of de-icing.

"We'll pre-wet the salt so, first of all, you use less of it because it's not bouncing, scattering across the road. And it goes to the center of the road and dissipates outward. The green salt is a magnesium chloride and that works like a slurry, and works at lower temperatures," Burns said after mentioning that DPW stopped using sand in 2006 because it provided little traction.

All the salt and liquids are eco-friendly, according to Torre and Burns. For example the brown colored "Magic Salt" has a coating of molasses. 

At the onset of any storm, DPW maps out a strategy, working backward from the anticipated end of the storm. Going into a winter storm, DPW's anti-icing strategy features a "direct liquid application" executed up to 24 hours prior to the storm event. This helps break down hard packed ice in extreme cold. 

Also, in particular, hills and curves throughout the city are pretreated.

"We kicked butt on Nemo," Burns continued. "We basically had everything done in Norwalk the day after the storm. All the schools and everything were done by Sunday at 7:00pm. We could have had schools open on here in Norwalk on Monday, but we didn't because the teachers couldn't get here. The city looked great."

"We're getting the right equipment so that we can be more efficient – faster, with less resources," Burns said. For example, Burns said the city's three new plow boxes are ideal for clearing school parking lots quickly.

With 60 sidewalks to clear and 625 lane-miles of city roadway to plow, plus responsibility for 22 school and civic parking lots, efficiency is important.

Indeed, not only is every vehicle in the fleet tracked by live GPS so every supervisor can see where the trucks are via an iPad or iPhone, but the City Works software puts all sorts of information at DPW's fingertips. Staff can constantly monitor progress on any of the city's 26 snow removal routes. 

And since salt is such a big budget item for DPW they are able to monitor its use carefully as well.

"We know how much salt each truck has used down to the pound," said Burns. "This enables us to pinpoint problems." 

According to Burns, the efficient use of salt is key because rock salt costs $58 a ton and treated salt comes in at $90 a ton, with a total annual cost of a half a million dollars. 

Beyond vast quantities of salt housed in the massive "salt house" on site, there are liquid tanks in the garage that replenish the smaller tanks on the individual plow trucks. A liquid application of magnesium chloride or a blend helps treat the road surface to prevent hard pack that plows can't remove.

DPW operates with only one shift of staff, so when there is a 24- or 36-hour storm it's the same plow operators during the entire storm. Burns said that during a long storm, staff don't go home during breaks, but rather, during eat at the operations center and sleep there on sofas and cots.

Ten years ago, according to Burns, "Ten years ago, snow plowing boiled down to 'How much is it going to snow?' and 'How much salt do we need?'" 

Burns and Torre described an intricate system of factoring in dew point, precipitation levels and dosage levels. They also consider the temperatures of the road surfaces and air temperature forecasts as variables in their calculations.

And, with a storm like Hercules DPW factors extremely low temperatures into their approach. The truck's electronic controls tell the driver what program to run for a particular timeframe. 

Challenges and Obstacles
Some challenges to snow removal are in the terrain, such as curves, hills and intersections. And then there's the cul-de-sacs. 

"Those trucks don't exactly turn on a dime, so there is tremendous skill involved," said Torre who added that trainees in the department will spend time with experienced operators to build their skills.

Perennial challenges to efficient plowing are cars out driving during a snow emergency, and, according to Torre, the issue of cars parked along the streets and homeowners shoveling snow back into the roadways are significant challenges.

With its system of live GPS tracking of DPW trucks, the city of Norwalk is a trendsetter and neighboring towns, including Wilton, plan to follow suit. 

Rilling mentioned that during Hercules he only received two complaints about snow removal, and was heartened to receive four or five calls complimenting DPW on a job well done. 

Check out the DPW Facebook page for individual photos of vehicles including plow boxes. Like DPW on Facebook to keep up to date with their operation.

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