Mag chloride – love it or hate it?
Eagle1s Tim Barka drives a rusted and pitted Œ84 Chevy Blazer with 210,000 miles on it bearing a sign contemptuously declaring 3Mag Chloride Test Vehicle.²
3I guess it1s kind of a statement,² Barka says. 3It1s a Colorado car. It1s not from the East Coast. I guess I didn1t wash it enough. It1s my bad weather car.²
Barka, an automobile mechanic, is living proof, however, there1s perhaps no substance more effective and more reviled than magnesium chloride, at least locally.
The love-hate relationship drivers have with the liquid de-icing salt is legendary. They love it because it keeps the roads largely ice- and snow-free; they hate it, however, because it coats windshields and vehicles with a brown, slimy grime.
One thing is certain: 3Mag chloride,² as it1s commonly known, isn1t about to go away completely anytime soon.
Use of mag chloride by highway crews has begun to generate a backlash, indeed, from citizens in mountain communities. Some of that backlash seems to orbit around the seemingly lost skill of driving on icy roads, fueled by the traditional struggle between locals and well-heeled and well-vehicled visitors, who may not negotiate icy roadways as well.
3There was a time when people used to know how to drive on ice. Now you buy the most expensive SUV you can get and go like hell,² says Eagle County Roads Supervisor Brad Higgins.
Higgins1 department does not use mag chloride to de-ice streets, but it does use it for dust reduction on dirt roads during the summer.
The City of Aspen no longer uses it to de-ice downtown streets, and nearby Glenwood Springs is considering doing the same thing.
The town of Avon stopped using mag chloride nearly a decade ago, said Public Works Director Bob Reed.
3We experimented with liquid magnesium chloride and found that it produced good results as an anti-icing agent, but it was somewhat corrosive to our equipment and damaging to the environment,² Reed says in a recent press release. 3Mag chloride adds a corrosive inhibitor, but it simply slows the inevitable process that results from chloride products.²
The town uses a more expensive de-icer, instead.
Steve Dziekan, a 23-year county resident, is taking his dislike of mag chloride one step further than Barka. He1s circulating a petition to ban use of the solution on all county roads.
3It1s really irritating and ugly to see this brown crap everywhere. It causes people to drive faster,² he says. 3CDOT does less plowing and they leave the stuff on the road. They1re looking for the easy way out. Aspen seems to be doing very nicely with plowing more and putting down sand and cinders and sweeping them up.²
Dziekan also is critical of the substance for the damage it creates to roadside evergreens and other trees.
For mag chloriders haters who want use the power of the pen to demonstrate their discontent, Dziekan says, copies of his petition are available for signing at:
€ Beaver Liquors and Nature1s Providers in Avon.
€ The Sole Man in Minturn.
€ Mountain Quest Sports in Edwards.
€ Bart n Yeti1s in Vail.
Dziekan says he1s trying to get 1,000 signatures. He plans to present his petition to the Vail Town Council and the Eagle County Commissioners.
More is less
CDOT Supervisor Paul DeJulio, a 20-year veteran of the department, is a big fan of mag chloride. In charge of keeping Vail Pass open in the days before mag chloride, he1s seen what it can do in terms of keeping traffic moving.
In 1994, for example, Vail Pass was closed by 38 times by accidents and wintery conditions. Those closures increased the pressure on CDOT to keep the vital transportation artery open, DeJulio says. More plowing and sanding, however, wasn1t the answer.
3All we did was fight sand all winter,² he says. 3All we did was put it down and pick it up.²
That routine has created a multi-million dollar cleanup on Vail Pass, where more than 300,000 tons of sand are eroding into Black Gore Creek, threatening to smother the watershed.
While it1s a matter of conjecture, just how to clean up such massive quantities of sand from often-inaccessible locations along the interstate, results were immediately apparent when the transportation department began using mag chloride in 1995, DeJulio says. Supervising a station for truckers to install highway chains at East Vail, he watched as a highway maintenance truck sprayed the substance on the icy roadway. Before long the ice was gone and the roadway stayed wet for hours.
Now, with some 600,00 gallons of the de-icer being used by highway crews on I-70 from Wolcott to Vail Pass and on Highway 24 to Leadville, the use of highway traction sand has dropped by nearly a third, DeJulio says.
During the winter of 1996-97, for example, 34,781 tons of sand were used, along with 274,800 gallons of mag chloride. Last year 25,759 tons of sand were used, along with 691,977 gallons of mag chloride.
3If we went away from it the accident rate would rise considerably,² he says.
DeJulio says there are some corrosion problems caused to his equipment by mag chloride. To counter them, he says, crews simply wash vehicles more often.
What about the environment?
In 1997, William Lewis, a professor of Limnology at Colorado University, concluded a three-year field study of mag chloride1s environmental toxicity along Clear and Straight creeks in Summit and Clear Creek counties.
3I think the case that this stuff is outright dangerous is very hard to make,² Lewis concludes in the study. 3Overall, preliminary environmental studies show no reason to expect environmental damage from magnesium chloride de-icer, especially if CDOT exercises control over metals and nutrients in rust inhibitors or as contaminants in de-icing materials provided by vendors.²
Lewis also studied the impact of mag chloride on aquatic organisms.
3We don1t have any field evidence of negative effects of mag chloride on aquatic organisms,² he says.
Typically the substance is diluted to levels where it has little or no impact once it hits area streams, he adds.
One impact, he says, is that mag chloride 3burns² roadside conifers. The phenomenon is well known on the East Coast, where rock salt is mixed with road traction sand, he says.
3It (mag chloride) doesn1t kill the tree; it just turns exposed branches brown,² he says. 3It1s unsightly, but it doesn1t extend very far from the road.²
Lewis recommends limiting naturally occurring concentrations of heavy metals in mag chloride, such as cadmium, copper and zinc. Those substances are found naturally in the Great Salt Lake and are concentrated by evaporation, he says.
3As long as we keep control of the composition and monitor what we buy from vendors, we will be okay² he says. 3We need to have some way of assuring levels of metals and nutrients are not exceeded.²
While the state1s massive transportation department has the wherewithal to ensure that, Lewis says, smaller road maintenance departments, such as those in towns and counties, may not.
3They may not know what they1re buying,² he says.
Division of Wildlife fisheries biologist John Woodling says he has not seen negative impacts from mag chloride use. The main impact has been positive.
3There1s less sand, and that1s good,² he says.
Works too well
Even Barka admits mag chloride has its uses.
3I don1t have problems with the stuff on roundabouts. But when you put it on the interstate, that1s just ridiculous,² he says. 3I can drive in winter weather. (Mag chloride) makes people drive faster because they have a false sense of security.²
The Colorado State Patrol does not have statistics on the relative safety or danger of using mag chloride. Those statistics could be difficult to interpret because traffic levels on the interstate have increased significantly over the years. Last year, for example, nearly 40,000 vehicles per day passed through Dowd Junction between Vail and Avon.
DeJulio said anecdotal evidence from state troopers suggest about 200 accidents per winter before mag chloride ‹ or four times the roughly 50 accidents per winter nowadays.
Facts about Œmag chloride1
€ Magnesium chloride1s ability to lower the freezing point of water is what helps keep roads open in cold weather. More importantly, it keeps maintenance crews from having to use more of the troubling traction sand.
€ The use of magnesium chloride in Colorado grew out of the massive project of constructing Interstate 70 through Glenwood Canyon. Environmental concerns about traditional salt and its negative effect on roadside vegetation ultimately drove the Colorado Department of Transportation, or CDOT, to use something besides highway sand, a mixture of sand and salt.
€ Mag chloride creates a smeary film when combined with road grime. Splashed by vehicles, it can obscure visibility by coating windshields and headlights. That tendency, which can make winter driving a mess, leads some to say mag chloride actually obscures all-important visibility.
€ Mag chloride corrodes metal and has been credited with causing power outages at electric substations when the salty mist kicked up by cars on nearby roadways drifts across transformers and power lines causing short circuits. That happened last winter in Eagle-Vail.
€ The de-icer costs 30 cents per gallon and is applied as a 27 percent solution at rates of 40 to 80 gallons per mile per lane of highway.
€ Crews applying mag chloride monitor temperature and roadways conditions constantly to decide when and how much of the substance to use.
€ Mag chloride can be applied to pavement in a light coat before a storm to prevent ice from bonding to the pavement. During a storm it can be used to melt what1s already there.
€ Highway crews still must use a salt-and-sand mixture for certain types of conditions where mag chloride may not work.
€ Unlike traditional salt-and-sand mixtures, mag chloride remains on the roadway when applied by highway crews before snowfall ‹ instead of getting blown off by passing vehicles.
€ Mag chloride prevents cracked windshields by reducing the use of sand and gravel, which gets flicked up by passing vehicles.
€ Mag chloride actually reduces roadside dust, a source of air pollution.