BOZEMAN — A Montana State University faculty member researching ways to rehabilitate soil made toxic by old mining practices recently received a Fulbright Specialist Grant in environmental science to work with Private Northern University in Peru to improve soil reclamation efforts in that country.
Tony Hartshorn, assistant professor in the Department of Land Resources and Environmental Sciences within the College of Agriculture, will travel to northern Peru for about three weeks this summer to explore innovative approaches to reclaiming land affected by mining. Like Montana, Peru has more than 8,500 abandoned or inactive mines. More than 4,000 “high risk” sites have been identified in Peru, with most of these mines, according to Hartshorn, presenting potential for contaminated soils without a “responsible party”—a company liable for paying for the cleanup—or even baseline environmental data.
“Though Montana has a 150-year legacy of gold, silver and copper mining, Incan miners across Peru were chasing the same precious metals 1,000 years ago,” Hartshorn said. “One problem with mining in general is when you crush rock to get the gold or silver out, you’re also liberating elements I refer to as ‘the Big Five’ — arsenic, cadmium, copper, lead and zinc.”
Arsenic, a dangerous chemical known to cause cancer in humans, and other carcinogens are common in areas near abandoned mines and smelting operations, such as the one in Anaconda, Montana, which processed nearly 190 million pounds of copper between 1919 and 1981, helping electrify much of the American West.
“The problem with super nasty chemicals like arsenic and lead is we have hundreds of square miles in Montana that are laced with high levels,” Hartshorn said. “Some contaminated soils in Montana contained more than 30,000 parts per million of arsenic — that’s a really large number.”
Although mining-affected areas in Montana and Peru face some of the same risks posed by the Big Five in the soil, water and air, the differences in climate, governmental regulations and lack of a Peruvian “Superfund” program require different approaches to mitigation. In Montana’s dry climate, arsenic carried by blowing dust is a top-level concern. The ecosystems are different in the 12,000-foot highlands of northern Peru, where it’s wet year round, and in the low-lying Peruvian Amazon.
“In Peru, where they don’t have a lot of blowing dust, the issue is acidity. If you open up a hole in the ground and subject that rock to oxygen and water, this can create acid mine drainage, which can contaminate water and soils alike.”
At the center of Hartshorn’s planned workshops and conference participation in Peru will be discussions of best practices across different ecosystems.
“Dr. Hartshorn’s work in soil remediation, reclamation and conservation is vitally important, especially in Montana and other places around the world with a history of mining,” said Charles Boyer, MSU vice president of agriculture, dean of the College of Agriculture and director of the Montana Agricultural Experiment Station. “This Fulbright grant will enable greater collaboration with international scientists working to make their regions safer and more productive.”
Hartshorn said there are ways to expand the remediation functionality of plants beyond simply stabilizing the soil.
“Because plants suck up nutrients through their roots, we’re researching ways to trick plants into slurping up these Big Five elements,” Hartshorn said. “If we could do that, then we could harvest and bale that plant material, burn it and safely dispose of the small amount of ash left over in a hazardous waste landfill.”
But, given Montana’s rich ranching legacy, there’s another possible tack to consider.
“We might want a rancher-preferred forage grass that grows well in contaminated soils but doesn’t absorb any of the Big Five chemicals into its leaves,” Hartshorn said. “That way, we may be able to safely graze cows there. This is an important stakeholder consideration in Peru as well, with many farmers hoping to be able to re-use reclaimed soils to support their families and livelihoods.”
Contact: Tony Hartshorn, (406) 994-6323 or Anthony.firstname.lastname@example.org