Findings of UW scientists could improve mine cleanup

CASPER — New scientific findings could transform the way Wyoming reclaims, or cleans up, its roughly 90,000 acres of land disturbed by surface mining.

Researchers at the University of Wyoming studied the results of an innovative reclamation technique known as geomorphic reclamation at two mine sites in southwest and central Wyoming. Ultimately, the scientists found the alternative process revived native plant vegetation and supported species diversity more effectively than traditional reclamation methods.

The findings, published by UW professor Kristina Hufford and graduate student Kurt Fleisher, unlock new possibilities for sustainable reclamation in Wyoming, if researchers can find a way to make the practice of geomorphic reclamation economical.

Geomorphic reclamation reconstructs the heterogeneous features of surrounding land to mirror the diverse conditions found before uranium and coal mining commenced. In comparison, Fleisher described more traditional reclamation as an effort to create “one, uniform landform.”

By cultivating a diverse landscape with multiple kinds of terrain and plants, geomorphic reclamation can promote a stronger and more sustainable ecosystem for both plant and animal species, the research found.

“The idea is to create a landform that resembles the native topography of the region,” Fleisher explained. “Because of the heterogeneity in the landscape, you have all these micro-climates that can support greater diversity and vegetation.”

Restoring the abundance of native sagebrush and rabbitbrush at old mine sites could also help preserve the state’s critical wildlife, like sage grouse.

Hufford and Fleisher worked on the grounds of a retired uranium mine site in the Gas Hills of Fremont County and a former coal mine site outside of Rock Springs in Sweetwater County.

Seeds were spread on the soil at each site as part of both traditional and geomorphic reclamation processes over a decade ago. In 2017 and 2018, the researchers investigated the sites to record the progress of the vegetation.

The sites where geomorphic reclamation was applied still did not restore the landscapes to its exact former state. However, “geomorphic reclamation was more likely to resemble undisturbed controls,” the report concluded. “Shrub abundance was up to 10 times greater on geomorphic reclamation compared to traditional reclamation.”

The results from the studies were published in the Journal of Environmental Management.

As for next steps, Fleisher said he would be interested in experimenting with different seed mix varieties to more closely mimic the vegetation in surrounding rangeland. A better understanding of how climate variations and topsoil quality affect geomorphic reclamation processes could also be a subject of future research, he added.

Wyoming Department of Environmental Quality’s Abandoned Mine Land program supported the research. The state has experimented with geomorphic reclamation on a small-scale over the last decade, especially after it ran into costly issues with traditional reclamation methods.

But the agency wanted to identify the most effective approach to revive and sustain the landscapes. The UW study, moreover, could help inform the state’s reclamation decisions down the road.

“The whole purpose of geomorphic reclamation is really to improve on the (traditional) model,” Fleisher noted.

Forging advancements in reclamation techniques could be critical to the future of the state’s public land. Compared to its Western peers, Wyoming has by far the most acreage of unreclaimed land disturbed by surface mining activity.

Of the 184,488 acres of mined land throughout Wyoming, 146,653 acres — about 80 percent — is being reclaimed or mined as of August, Wyoming Department of Environmental Quality data showed.

About 106,964 acres — or 73 percent of disturbed land from mining — are in one of three phases of reclamation. Wyoming has cleaned up over 50,000 acres to a state adequate for agricultural production too, according to the department.

But a new report published this month by the Western Organization of Resource Councils came to graver conclusions. Throughout the West, over one-third of all land disturbed by strip-mining has yet to be reclaimed after 50 years of intensive extraction in the region. Nationwide declines in coal demand have left companies financially vulnerable and at risk of foundering on reclamation liabilities too, the report concluded.