Dave Dethloff’s job is to keep a 52-mile section of Interstate 84 as safe as possible for travelers despite Baker County’s occasionally polar climate.
He’s sold on salt.
As the Oregon Department of Transportation (ODOT) moves through its second winter using salt to combat snow and ice on Interstate 84 from Boardman to the Idaho border, Dethloff, who manages ODOT’s Baker maintenance section near the Milepost 302 interchange in north Baker City, said salt has proved its value.
“It’s incredibly effective in just about any condition,” Dethloff said.
When temperatures are moderate, salt helps prevent falling snow from sticking to the freeway, he said.
And when the temperature plummets and a layer of ice forms, salt can start to melt the ice and help plows scrape it off the pavement more thoroughly and quickly.
“It’s been a huge tool for us,” Dethloff said. “We’re getting better driveability for the public, and that’s the goal.”
Although many states have used salt for decades to deal with snow and ice, Oregon officials had long resisted doing so in part due to concerns about salt corroding vehicles and polluting fish-bearing streams.
In 2012 ODOT started a five-year pilot project in which it spread salt on a mountainous section of Interstate 5 near the California border, and on Highway 95 in Oregon’s southeastern corner.
ODOT officials said the experiment on I-5 and Highway 95 showed the benefits of salt, and in 2017 the agency enacted Phase 2 of its pilot project, which includes using salt on Interstate 84 between Boardman and the Idaho border (for a list of areas where salt can be used, see boxed story at right).
That roughly 200-mile section includes areas infamous for nasty winter driving conditions, including the Blue Mountains, Baker and North Powder valleys, the Burnt River Canyon and Three Mile Hill between Farewell Bend and Ontario.
Dethloff acknowledges that neither last winter, nor so far the current version, was as snowy as the 2016-17 winter, which brought near record amounts of snow and sub-zero temperatures to Northeastern Oregon.
But he said both this winter and last were meaningful tests of the efficacy of salt, and in almost every case the simple compound passed.
“We knew it was going to be a good tool (based on the pilot project on I-5 and Highway 95), but we didn’t know how successful it was actually going to be,” Dethloff said.
Besides helping ODOT crews keep the freeway clear during and after winter storms, he said salt has greatly reduced the need to spread traction-adding rock on the freeway.
As of early this week, Dethloff said the Baker maintenance station has gone through about 80 cubic yards of salt on its section of I-84 during the winter season, starting Nov. 1.
By comparison, during previous winters — the entire winter, not just through early January — the station has dumped around 1,000 tons of rock, Dethloff said.
In past winters, he said, crews often had to apply sand multiple times as falling snow covered the previous layer.
Using salt instead has often alleviated the need to use any sand.
Dethloff said ODOT workers are still learning how to get the best results from salt.
“We’re still learning as an agency,” he said. “I think it’s going to take a few more years to fine-tune all the equipment and make sure it’s dialed in.”
Dethloff said drivers have settled on a maximum application rate of 200 pounds of salt for one lane over one mile.
In some conditions they are distributing salt at half that rate — 100 pounds per lane mile.
“The goal is to use as little as possible and still be effective,” Dethloff said.
ODOT’s application rates are low compared with the figures listed in a guidebook from the Salt Institute, a nonprofit trade association in Virginia that promotes the use of salt on roads.
The Institute’s “Snowfighter’s Handbook” lists a variety of salt application rates depending on road conditions and temperatures, but in most cases the group recommends rates from 150 pounds to 400 pounds per lane mile.
ODOT crews continue to use another de-icing chemical, the liquid magnesium chloride.
Drivers apply magnesium chloride on secondary highways — salt at this point is used only on I-84 — in advance of storms to reduce the risk of ice forming, Dethloff said.
The de-icer leaves distinctive parallel lines along the highway, and is useful on shaded corners and hills, he said.
ODOT also mixes magnesium chloride with the salt — about 20 gallons per ton of salt, a process known as “pre-wetting” — to make the salt more effective, Dethloff said.
According to the Salt Institute, “salt needs moisture to provide melting action.”
See more in the Jan. 9, 2019, issue of the Baker City Herald.