Wednesday April 2, 2025
Desert Research Institute —
Mountain snowpacks accumulate snow throughout the winter, building up stores of water that will supply communities across the American West throughout the long dry season. Now, a new study shows that as storms carry snow to the Rocky Mountains, they are also bringing mercury and other contaminants from mines in the region. The research helps scientists understand how contaminants are spread by atmospheric circulation and has implications for snowpack preservation and illuminating the lasting environmental impact of mining activities.
The study, published in the May issue of the journal Environmental Pollution, examined contamination levels for Mercury, Zinc, Cadmium and Antimony from nearly 50 sites in the Rocky Mountains. DRI’s Monica Arienzo, Associate Research Professor of Hydrology, led the research, along with colleagues from the U.S. Geological Survey (USGS), the University of Nevada, Reno, and Portland State University. They found higher levels of metal contaminants in the northern Rockies and identified mines in the Pacific Northwest, Idaho, and Montana as the likely source by following winter storms back in time. It is one of the first studies to look at metal contamination across the greater Rocky Mountains.
“Metal pollution in the Rockies is relatively understudied,” Arienzo said. “Other studies have focused on certain parts, so the fact that we have this transect from Montana to New Mexico makes this study unique.”
Although contamination levels were found to be within guidelines set by the EPA for both drinking water and aquatic life, dust can accelerate snowmelt by decreasing the reflectivity of the snowpack. The data can also provide critical information about how environmental contaminants and dust are distributed by the atmosphere.