Mag chloride spills on Highway 40 and into Colorado River

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photo courtesy of Grand County Sheriff Office
photo courtesy of Grand County Sheriff Office

by Marissa Lorenz
Traffic was restricted through Byers Canyon for most of the day on Tuesday when a tanker truck carrying magnesium chloride tipped over, spilling about 4,200 gallons of the liquid compound into the Colorado River.

According to Colorado State Patrol (CSP), the eastbound tanker was traveling too fast when it entered the final right-hand curve before Hot Sulphur Springs. The driver hit the brakes,causing the liquid freight to shift and tipping over the trailer and cab. The vehicle came to rest across both lanes of the federal highway, with the rearmost 15 feet of the trailer extended beyond the guard rail and hanging over the steep embankment.

Grand County Sheriff’s Office, Grand County EMS, and Grand Fire responded to the scene. State Patrol responded with troopers, representatives from the CSP Motor Carrier Safety Assistance Program, and a Hazmat (Hazardous Materials) crew.

The Colorado Department of Transportation (CDOT) was on site to repair about 50 feet of torn guard rail. And ECO’s Environmental, a private contractor out of Grand Junction, responded to continue clean-up efforts.

The driver of the tanker was transported to Middle Park Health in Granby where he was treated for a laceration to his
head and a shoulder injury.

Hazmat specialists attempted to mitigate the spill by plugging the holes with absorbent socks and using kitty litter and dirt to absorb the leaked fluid. But “efforts ultimately failed,” stated the report, due to the location of the punctures and the hydraulic pressure behind them. An estimated 4,200 of the 4,500-gallon load of 30% magnesium chloride made its way down the steep slope toward the Colorado River.

Magnesium chloride is a salt used to stabilize and suppress dust on unpaved roadways, reducing maintenance costs, and can be used to de-ice paved roads in the winter.

According to the Colorado State University Extension Office, “High concentrations of [magnesium chloride] ions in the soil may be toxic or change water relationships such that plants cannot easily accumulate water and nutrients.” The compound can accumulate in plants, ultimately leading to death.

And though the salt compound is water-soluble, a 2017 CSU Extension and Colorado Parks & Wildlife study determined that mag chloride as a road treatment can result in “significant reductions in abundance, taxa richness, and community biomass” of important aquatic macroinvertebrates and that effects were observed at considerably lower concentrations than those reported in traditional lab toxicity tests.

The application of the substance has been banned or restricted for environmental reasons in many Colorado mountain communities, such as Aspen, Vail, Basalt, and Summit and Moffat Counties.

Grand County Water Quality Specialist Katherine Morris reported that, at the time of the spill, water flow in the river was about 195 cubic feet per second (cfs). She stated that “even if the full volume of the spill entered the river in the course of one minute, it would constitute less than 4% of the river’s flow. Though I don’t have concentration information, that’s a pretty favorable dilution rate.”
Morris pointed out that some of the spill would have been absorbed by the soil on the hillside and that it will likely be flushed
out in smaller quantities through future rains and snowmelt.

“Both magnesium and chloride are naturally occurring ions, which are very mobile,” she explained. “They will continue to dilute, and that’s good. It’s only in the concentrated solution when they can be harmful.

“This being a point source in the river, fish and aquatic life could move away from the plume. Aquatic insects would do this by letting go of the rock and ‘drifting’ to a less concentrated area. Fish would swim to the side, upstream, or downstream.”
Morris indicated that, as a courtesy and precautionary measure, downstream irrigators were notified of the spill and advised “to close headgates at their discretion to avoid drawing sodium into their fields.” The Town of Kremmling was also contacted, confirming
that they are not currently and do not plan to utilize their Colorado River intake any time soon.

Katlin Miller of the Middle Park Stockgrowers Association indicated that, while some landowners are still irrigating, the recommended 18-hours of headgate closure was “not enough time to have a significant impact on most irrigators’ water supply.”

CPW and the Colorado spill-reporting hotline have been notified of the Byers Canyon mag chloride spill. The State and CPW will continue to monitor for impacts, although Morris assures, “As far as the extent of downstream impacts, I think it will dissipate fairly rapidly, and I don’t anticipate measurable impacts downstream.”

Coincidentally, while siren-blaring first responders rushed past the County Admin Building toward the scene of the accident, Grand County Superintendent of Road & Bridge Chris Baer was informing County Commissioners of a possible shortage of magnesium chloride due to the recent mudslide-related interstate closures near Glenwood Springs.

Baer noted that, with transportation hold-ups and recent weather patterns including rain, the County may not be able to conclude its planned 2021 mag chloride, road-stabilizing treatments.

On Wednesday, Baer confirmed that the mag chloride involved in the spill was not being delivered to Road & Bridge but that current material availability and weather were expected to be favorable for the completion of the road treatment process over the next couple of weeks.

If those treatments cannot be completed, Baer observes that it would save some money in the County’s 2021 budget but would increase the longer-term costs to maintain and repair roads that went untreated.