Severe winter weather has forced state and local road maintenance crews to use more road salt than anticipated so far this winter season.
Typically the Ohio Department of Transportation District 11 uses from 48,000 to 52,000 tons of road salt during the winter. The district has already used about 47,000 tons with a month left of winter driving, according to Becky Giauque, public information officer.
"We are farther into our stockpiles than we would have expected at this point in the year," she said."Our record usage was 55,000 tons."
District 11 encompasses a seven-county region in eastern Ohio, including Belmont, Carroll, Columbiana, Harrison, Holmes, Jefferson and Tuscarawas counties. District 11 is responsible for 3,300 lane miles of roads and over 1,000 bridges utilizing 125 trucks and over 200 drivers. After a road is first plowed, de-icing chemicals are usually applied in a windrow two to four feet wide down the middle of a two-lane road.
"We are in no danger of running out of salt," Giauque said. "All seven of our counties have ordered additional salt."
Giauque explained that plain road salt is effectively useless in the subzero temperatures that are expected in Ohio for the next two days. The ODOT chart for pounds of ice melted per pound of salt at different pavement temperatures shows that at 30 degrees one pound of salt melts 46.3 lbs. of ice. As the temperature drops so does the effectiveness of salt.
"The surface temperature of a snow- or ice-covered road determines de-icing chemical amounts and melting rates," Giauque explained. "As temperatures go down, the amount of de-icer needed to melt a given quantity of ice increases significantly. Salt can melt five times as much ice at 30 degrees F as at 20 degrees F. The effectiveness of de-icing is also sensitive to small differences in pavement temperatures.
In addition she stated that ODOT uses calibrated salt spreading machines that control the amount of salt distributed according to the snow and ice conditions on the roadways. Additionally, ODOT plow trucks have infrared temperature sensors which allow operators to see the exact surface temperature of the roadways, so they apply the right material.
Using one pound of salt at 25 degrees the amount drops to 14.4 lbs. of ice, at 20 degrees 8.6 lbs. of ice, 15 degrees 6.3 lbs. of ice, 10 degrees 4.9 lbs. of ice, 5 degrees 4.1 lbs. of ice and at zero the amount of ice drops to 3.7 lbs. The time that salt takes to melt one-eighth inch of glare ice increase from 10 minutes at 30 degrees to nearly an hour at just 20 degrees colder.
According to ODOT policy, once the temperature drops below 15 degrees, they will start to utilize calcium chloride or other additives to melt snow and ice. In extreme cold conditions, ODOT combines rock salt with liquid calcium chloride to better melt ice. This salt additive is effective on roadways with pavement temperatures up to negative 25 degrees Fahrenheit.
The state is also using a sugar beet juice product called Geo Melt blended with salt brine in Tuscarawas and Carroll counties. The blend has been poured out of tankers in preparation for sub-zero temperatures, coating bridge decks and overpasses since 2007 in the district.
The Deicing Product marketed as Beet 55 is a natural organic product made from sugar beet molasses blended with Calcium chloride. The manufacturer contends the mixture reduces corrosion levels by 70 percent, improves longevity of Calcium by 1 to 2 days and will melt more snow and ice than straight calcium by a 10 to 20 percentage.
The contention is that the juice reduces the total chloride load to the environment by 43 percent and neither stains the roads nor attracts animals.
Giauque explained that the shovel-able snow event this past weekend is not the main culprit for the above average salt usage, "The little events, the one to two inches of snow spaced 12 or so hours apart are real salt burners."
Throughout severe winter events, ODOT crews constantly monitor pavement conditions with road sensors scattered throughout the state and treat areas that are re-freezing. "We're continually monitoring the road conditions and we'll have crews out as conditions warrant," Giauque said.
Even though most eastern Ohio roads are safe and passable this morning, the Ohio Department of Transportation District 11 office is urging drivers to remember in Ice and SnowTake it Slow," Giauque warned.
With a winter weather advisory and wind chill warning in effect for much of the state through Wednesday, it's important for motorists to understand how quickly wet roadways can freeze, creating dangerous patches of ice. A winter weather advisory means that snow and a flash freeze of wet roads are possible and can cause travel difficulties.
Wind chills are predicted as low as 30 below due to temperatures and winds of 15 to 35 mph. The lowest wind chill values are expected tomorrow morning, and with visibility reduced at night and in the early morning hours, drivers need to be cautious of black ice.
Current air temperature, surface status and temperature, and visibility among other things are easy to view by visiting ODOT's Web site for traffic and road condition information www.ohgo.com and selecting the Road Sensors icon located on the menu at the right side of the page.
Palmer may be reached at firstname.lastname@example.org