The Desert Research Institute in Reno, Nev., examined snow samples from nearly 50 sites in the Rocky Mountains. Researchers melted down the snow and found mercury, zinc, cadmium, and antimony in the water.
Mountain snowpack acts as a frozen reservoir that supplies water to communities, and it “serves as a recorder of what's in our atmosphere,” said Monica Arienzo, an associate professor in hydrologic sciences at the institute who led the study.
Arienzo said the region has a long history of mining for those specific metals. What’s more, the drilling, blasting and extracting at mine sites produces metal dust that spreads through the atmosphere and into the snow and eventually ends up in the region's water supply.
Contamination was highest in the northern Rockies, across Montana, Idaho and northern Wyoming. That’s where several historical mines are federal Superfund sites. That means the clean-ups of some of the nation’s most contaminated land are being overseen by the Environmental Protection Agency.
“We really recommend that we continue to have remediation of the Superfund sites,” said Arienzo, adding that the pollution caused by active mining should also be closely monitored.
For now, she said the metal contamination in the Rockies’ snowpack is fairly low, and within federal guidelines for both drinking water and aquatic life.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
