Plows become more eco-friendlyThey’re big and they’re sturdy — at first glance, Cottage Grove’s fleet of plow trucks looks more like public works workhorses than pieces of high-tech machinery.
By: Jon Avise, Woodbury Bulletin
They’re big and they’re sturdy — at first glance, Cottage Grove’s fleet of plow trucks looks more like public works workhorses than pieces of high-tech machinery.
But more than $50,000 in funds from the South Washington Watershed District is changing that, helping the city install a computer-based road salt distribution system in its dozen plow trucks. That, says a public works official, will save the city money and keep the potentially environmentally harmful salt from washing away into area ponds and wetlands.
The computer systems — at a cost of about $24,000 to the city, $75,000 in total — sense ground speed and road temperature, delivering just the right dosage of ice-melting road salt to slick streets and eliminating piles of the white stuff at intersections.
“We’re not looking to compromise pubic safety,” said city engineer Jennifer Levitt. “The key thing is we still want to put out the right amount of salt, we want the same results with the least amount of salt (usage) possible.”
The trucks also feature GPS systems that will help public works evaluate and possibly rework the city’s plow routes.
Since 2001, Cottage Grove’s plows have applied an average of 5,200 tons of sand and salt per year to the city’s 168 miles of roadway, according to statistics provided by public works. Cottage Grove Public Works has moved to phase out the use of sand — except in extremely low temperatures, when salt loses its effectiveness — saying the substance does little to improve road conditions and is expensive to clean up.
Levitt said last week the city estimates the new salt distribution systems will reduce the city’s salt usage by 5 to 10 percent — valuable, considering the wintertime necessity cost the city $56.40 per ton this year.
“The cost of salt has gone way up,” said public works streets foreman Gary Orloff. The in-plow computers will be “better for runoff, water quality, and salt usage.”
Plow drivers will manage the computer system with a single joystick, an easier task than dealing with the series of levers and buttons that controlled the release of salt and sand in the past, Orloff said.
The computer system will sense road temperature — applying more the colder the surface — and vehicle speed — slowing the spread of salt from the truck bed as a plow slows at an intersection to allow for an even distribution.
It’s more scientific, by a long shot, Orloff said, than how plow drivers were applying salt and sand in the past.
“It was a sight thing,” he said. Now, plow drivers “can keep an eye on the road more than what you’re doing in the truck.”