TRAVERSE CITY — As Traverse City leaders push to reduce salt use on city streets, the city Department of Public Services is exploring its options.
Frank Dituri, director of the city DPS, told commissioners Monday that he’ll ask them in a week to approve buying a V-box spreader for a new plow truck. That’ll allow the truck to spray brine where local streets intersect.
City Streets Superintendent Chris Weber said the department selected a route that doesn’t overlap with many others so the DPS can evaluate the de-icing technique.
It’ll be the second time since 2019 that the department has experimented with using liquid de-icers instead of rock salt or a mix of liquid and salt crystals, Dituri said. He’s looking to Kalkaska County Road Commission, which is experimenting with spraying intersections at a rate of 30 gallons per lane-mile with a mix of Beet Heet and De-Ice Master Plus, two proprietary liquid de-icers.
“They’ve had really good results with reduced use and promising performance,” he said. “So there certainly are alternative uses we’re looking for and are on our radar, and you’ll see purchasing requests coming to the commission in the coming weeks that are requesting some of this equipment.”
Dituri said the department already cut salt use by 42 percent by spraying it with a 50-50 mix of Beet Heet — a mix of four sugars derived from beet molasses and four chlorides — and 23-percent brine, at 15 gallons of solution per ton of salt.
Prewetting helps salt stick to the pavement, preventing loss from scattering, and helps kickstart the melting process. Beet Heet takes both even further, making salt crystals even stickier and dropping the effective temperature from 15 degrees for untreated salt to as low as minus 10.
All told, plow truck drivers spreading 200 pounds per lane-mile, on par with other northern municipalities Dituri spoke with in recent weeks. Others use more, with a few using up to 600 pounds per lane mile.
In response to a later question from Commissioner Jackie Anderson, Dituri said the DPS’ approach to treating a road surface to make it safe for travel varies from street type to street type. For Michigan Department of Transportation routes, the state highway agency expects the city to keep the entire road surface free and clear of ice and snow, within reason. City plow truck drivers use the same approach for emergency routes to ensure first responders can reach people who need emergency services.
For local streets, plow drivers still clear snow but only spread salt sprayed with brine and Beet Heet in and approaching intersections, Dituri said.
Anderson asked if Dituri is confident the current policies and procedures are as “salt-thrifty” as possible. Dituri responded the DPS could change its approach if city commissioners desire.
“I think from what you’ll hear from staff is that right now we’re doing it the best way we can in the safest manner we can, but if the body decides to do something different, you certainly have the option to do that,” he said.
Along with another trial of using liquid de-icer only — a previous trial in 2019 proved the city needed better gear than a sprayer made in the DPS garage — Dituri also requested the city consider a policy that it purchase up to 2,500 tons of salt per year.
That wording prompted some confusion, with city Manager Liz Vogel adding the idea is to start with the same amount every year. Commissioner Heather Shaw wondered if the goal is the same, is the city actually using less salt, and Anderson noted the data she found showed the city didn’t buy or use nearly that much salt in the last several winters — she later requested more complete data from Dituri, to which he agreed.
Dituri responded the 2,500-ton figure comes from analyzing years of salt use — it’s also the DPS salt barn’s capacity, although a second barn could hold more. He agreed the idea of his proposed policy is to buy, say, 2,000 tons before winter if the city still has 500 tons left in the barn. He’ll ask commissioners to buy that much on March 17 as well.
The city makes its own brine using the road salt it buys and a brine maker bought in the 1990s, Weber said. While Shaw asked whether using brine actually cuts down salt use, he responded it undoubtedly does.
Weber also showed commissioners a bag of different de-icers, including salt as it arrives from suppliers Morton Salt or Detroit Salt, and as it appears as city plow trucks apply it. He also showed them a bag of calcium magnesium acetate. The compound is used on the Zilwaukee Bridge in Saginaw County, as required by law — it’s less corrosive to both iron and concrete.
“So you don’t get the concrete spalling like you get from salt, but it is required by law and it’s very expensive,” he said. “A ton of salt costs approximately $73 to $75, and a ton of this is $2,400.”
Shaw wondered if setting a policy to start each winter with 2,500 tons of salt made sense, given the goal is to cut use. Weber responded this could be reevaluated, noting the highest use over the last 10 years was roughly 2,400 tons. For the current winter so far, the city has used about 1,700 tons.
Weber agreed he wants to see the city use less salt. With Beet Heet already showing promising results and Kalkaska County Road Commission’s own trial run with liquid de-icer, he’s looking to thoroughly evaluate liquid de-icer in Traverse City over the coming winter.
Monday’s discussion followed a vote where commissioners agreed to buy 500 tons of salt, but only if city staff came back with a presentation about how much the city uses and why. While Dituri previously cited the city’s responsibility to maintain safe travel conditions, commissioners noted road salt’s impact both on infrastructure and the environment.
Sarah U’Ren, program director of Watershed Center Grand Traverse Bay, said those impacts are apparent in Kids Creek. In-stream monitoring shows spikes of chloride levels when snow falls or melts, and that’s impairing water quality in the stream.
U’Ren echoed Dituri in noting he’ll meet with the Watershed Center Grand Traverse Bay in the coming week, adding the environmental nonprofit will keep working with the DPS.
Weber said earlier that, as a lifelong city resident, he understands the concern, as does DPS staff.
“Our No. 1 is safety, our No. 2 is the environment,” he said.