June 12—TRAVERSE CITY — The source of a mysterious spill at a US 131 roundabout in Fife Lake a week ago was confirmed as a truck traveling on Grand Traverse County roads.
The slippery substance, later identified as a harmless calcium chloride solution used in brining, closed the highway for several hours on the evening of June 5 so Fife Lake Springfield firefighters could clean up the spill.
A tanker truck operated by Great Lakes Chloride, and retained by the state road commission for brine roads, was the source of the spill, said Zach Clothier, a GLC representative in Michigan.
“The truck had a leaking valve and the driver stopped to properly close it after noticing the leak,” Clothier said.
The roadway reopened at 1:15 a.m. on June 6.
Dust control on unpaved roads in the province is currently a high priority for a number of reasons: Dust not only reduces visibility, it can also wear out mechanical systems in vehicles. Additionally, road dust and other non-exhaustive fine particles may be linked to acute and chronic cardiovascular problems, according to a 2022 scientific study published in the journal Environmental Science Technology.
This year, the road commission will spend more than a quarter of a million dollars to control road dust through this process called “brining.”
The costs for this are usually shared with the townships on a 50-50 basis. And the county highway commission contracted with GLC to do the work.
“Our contractor completed 175 miles of dirt roads across the county last week,” said Larry LaCross, superintendent of field operations for the road commission.
“We are trying to get the dust control done before Memorial Day,” LaCross said, “but this year there was a shortage of the (brine) material and we had to make our first application the week of June 3.”
Another 260 kilometers of unpaved roads were not brined in the final round, mainly because they are too small for the large brine tankers to turn on.
This year the county is paying just under 86 cents per gallon for brine solution. Brining one mile of dirt road requires approximately 1,900 gallons of brine, which works out to approximately $1,630 per mile. (In contrast, building one mile of new paved road costs about $2 million.)
All townships in the province participated in the brining process this month. A second round of dust brining will take place later this summer or fall. But not all townships are asking for the second round, Lacross said.
What is brining?
Brining involves spraying a liquid solution of calcium chloride and water onto unpaved roads using tankers with special nozzles on the lower back. The solution adheres to dust, clay particles and other fine material on the roadway.
Because calcium chloride is a “hygroscopic salt,” it tends to attract ambient moisture from the environment, increasing dust control effectiveness and reducing sediment runoff into nearby streams and rivers.
Calcium chloride also resists evaporation, making one application long-lasting. Intermittent rain can help reactivate the solution, industry officials said.
Before brine is sprayed, all gravel roads being worked on must be graded or knifed, officials said. Leafing involves shaping the crest or slope of a roadway, as well as associated shoulders and drainage dips, to prevent water from accumulating on the surface.
Not only does brining help improve road user safety and reduce exposure to dust particles, it can also reduce maintenance costs associated with gravel roads and replacement.
GLC, headquartered in Warsaw, Indiana, uses a calcium chloride solution called “Liquidow,” which is 53-72 percent water (by weight) and 28-42 percent calcium chloride. It also contains less than 3 percent potassium chloride and calcium chloride (table salt).
Calcium chloride brine is not considered dangerous or carcinogenic according to federal regulators, although it can irritate the skin and eyes with direct exposure. Walking with shoes along a recently salted road is not considered direct exposure.
“If you walk barefoot along a road that is still wet from brining, just wash it off with water,” Clothier said. “We don’t use oil-based brine at all.”
Calcium chloride solution is one of four products approved by the Department of Environment, Great Lakes and Energy (EGLE) for road brining without a permit, he said.
“When we apply the dust control, the surface is wet for some time,” Lacross said. “I would wait until the Liquidow soaks into the gravel and dries before letting your pets walk over the application area.”
ENVIRONMENTAL DEBATE
The use of salt-based products, such as road salt and brine, is the subject of debate among state regulators, environmental groups and county road commissions.
Michigan has about 35,000 miles of dirt roads, many of which have been treated with brine to tamp down the dust.
According to researchers at Grand Valley State University, runoff of chlorine-based materials has seriously affected water quality in areas such as Church Lake in Grand Rapids in recent years.
The region’s dependence on rock salt is even causing Lake Michigan to become salinized, according to a 2023 report from Bridge Michigan. Toxic algae blooms caused by nutrient overgrowth are also a growing problem in the Great Lakes region.
However, chlorine levels in lakes and waterways may be more related to the sodium chloride used in rock salt, rather than the calcium chloride used for brining dust.
Tests show that calcium chloride is less harmful to plants and less corrosive to metals than sodium chloride, according to the U.S. Environmental Protection Agency.
Today, sodium chloride (“rock salt”) is the most common substance used for deicing roads and highways, largely because it is much cheaper, EPA officials noted. By comparison, calcium chloride can be up to three times more expensive, she added.
Due to looming calcium chloride price increases, the county road commission took action earlier this year to negotiate lower-cost brine contracts, drawing praise from county commissioners.
Efforts to regulate chlorine-based road construction products in Michigan have had little success.
Last year, state EGLE officials proposed new road brining limits, but withdrew after strong opposition from county road commissions who said there was no effective alternative to calcium chloride brine.
Other possible brine solutions, such as oil-based brine, agricultural byproducts and asphalt emulsion, are just as bad – or worse – from an environmental perspective, according to Bridge Michigan.
Ultimately, the future of brining in Michigan may depend on deeper environmental and chemical studies, the data of which could then support more informed decision-making at the regulatory level.
