Earlier this week, the Telluride Daily Planet reported that Telluride, a small Colorado mountain town located some 300 miles southwest of Denver, was experimenting with a new type of dust control for its unpaved roads. The most common dust control suppressants contain a relatively high amount of magnesium chloride, which, as a 2009 study from Colorado State University revealed, can negatively affect roadside vegetation, of which Telluride has plenty. The study concludes that non-chloride based products are the safest form of dust suppressant.
The formula that Telluride is experimenting with has less of the harmful magnesium chloride. Yet, as Telluride road superintendent Mike Horner told the Daily Planet, the new suppressant is more expensive and labor intensive, and they'll likely stick with the old version "unless [the new one] really works." But why? If the new mixture reduces the amount of harmful magnesium chloride introduced into the local environment, even just a little, isn't it worth it? Well, it turns out that suppressing dust, and suppressing it efficiently, is very important to Telluride. The 45 miles of dirt roads strewn throughout San Miguel Country—which encompasses Telluride—and its dust has a large effect on one of Telluride’s biggest sources of revenue: snow.
It seems that dust, often regraded as nothing more than a minor nuisance, can have all sorts of negative natural ramifications.
When dust is kicked up by cars and settles on neighboring snow banks—or snow much farther away, depending on the quantity of dust and wind speed—it directly affects the snow’s albedo, or its reflecting power. Snow, when met with the sun's harsh rays, is able to re-direct the heat skyward and keep the ground nice and cold. A layer of dust coated across the top, though, turns that mirror-like surface into one that traps heat, and in turn speeds up the melting process.
Way back in 1987, researchers in Alaska noted the large role dust played in "early phase melt-off" and soil thaw. In Alaska, the early snowmelt would not necessarily affect skiing—although, as one of the world’s premier heli-skiing sites, it could—but more the wildlife. Researchers found that caribou, grizzlies, raptors, and ptarmigans all return to usually snow-covered areas before they normally would as a result of dust-induced melting. It seems that dust, often regraded as nothing more than a minor nuisance, can have all sorts of negative natural ramifications.
A study by researchers at the University of Colorado found that in 2009 and 2010, years of particularly high dust levels, snowpack melted almost two months early. Additionally, the 176-page 2015 Colorado Climate Change Vulnerability Study, a joint report from the University of Colorado and Colorado State University, made special note of the effects that dust deposition has on snowpack and resulting runoff into the Upper Colorado River Basin. Now, most of the dust that these studies address blows in from the nearby desert, but on a much smaller scale, the same principle applies to the dust kicked up by cars on unpaved roads.
"This product is more expensive and more labor intensive. Unless it really works, we probably don’t have a lot of time to spend doing the miles," Horner told the Daily Planet, referring to the county's trial run. Last summer, for the third year in a row, Telluride drew more revenue from tourism during the summer than it did winter—and this in a town that’s considered to be one of the best ski destinations in the world. If there’s a way to save even just a bit of snow for Telluride’s ski season, it seems city officials are going to do it. For now, that means some form of magnesium chloride on its unpaved roads.
*Special thanks to Mary Slosson for suggesting Telluride as a point of coverage.