Mining Careers aren’t Just for Mining Graduates

Restoration ecology graduate student Sierra Lauman saw her future in forest restoration, maybe with a government agency like the U.S. Forest Service. In pursuit of her doctorate at the School of Natural Resources and the Environment, she’s focused on investigating better methods for revegetating lands disturbed by hard rock mining. Now, after three years of studying revegetation of legacy mine waste at an active operation, Lauman has added mining to her list of potential career areas, an option she didn’t know existed. “I had no concept of what went on in mining, much less what happened when it closed and needs to be cleaned up,” says Lauman.

Examining how seeds germinate at a closed smelter site in Superior, Arizona, led her to consider expanding her opportunities. The project by the University of Arizona’s Center for Environmentally Sustainable Mining (CESM) was suggested by partner Resolution Copper, which inherited the site after its closure. The company sought to determine the best way to take advantage of seasonal rains to grow plants in areas that won’t be irrigated. Researchers also wanted to test the effectiveness of a fungal soil treatment.

Mine reclamation project needed a plant expert

Resolution removed desert vegetation and top soil to rid the land of dangerous levels of arsenic left by the old Magma Mine operation. In a 2019 randomized trial, CESM worked with Resolution Copper to seed plots under several different conditions. Treatments included hydroseeding just before either summer or winter rains with or without a fungal soil amendment. Hydroseeding sprays a mixture of fertilizer, soil treatment and seeds onto a landscape. Another plot was sown with seed balls tossed on top of the soil. These mixtures of clay and fertilizer break up in rain to release seeds. A final plot was left unseeded as the control.

As each plot was seeded at the proper time, the research team waited for rain. But no substantial rain came in the summer monsoon of 2019 and the winter of 2019. None came for the summer of 2020. By fall of 2020, few seeds had germinated in any of the plots, and the treatment “became null and void,” says CESM Director Julie Neilson.

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Wanting to save Resolution’s investment in the project, Lauman in 2021 decided to test the viability of seeds in the experimental plots. It turned out that several dozen species of the sown seed grew well in a greenhouse environment, showing that the seeds were not only viable, but ready to germinate and grow when conditions were right. Additionally, Lauman discovered that some species did better in germinating than others. That provided a tantalizing clue of how to proceed. Maybe seasonal planting for revegetation isn’t as important as what you plant and where you plant them. “Even within a mine site not every species that you put out on a hillside will do well,” she says.

Lauman’s seasonal seeding project received funding from the Mineral Research and Innovation Initiatives program by the UArizona’s new School of Mining and Mineral Resources.

Initiative backing expands mine restoration research

Armed with $53,768 from the program and $120,000 from industry partners, CESM aims to expand its ability to research and address environmental issues that face mining operations. Resolution Copper says it values this cooperative work. “Our partnership with CESM is an important part of our effort to build a 21st century copper mine, which sets a new standard for safe and responsible operations,” says Brad Lingard, who leads the firm’s health, safety, environment and security team. “We are committed to understanding the impact our operations may have on the environment.”

“One of the goals of CESM is spreading the reach of the mining department into the area of sustainability in mining,” Neilson explains. “We say sustainability issues are more the area of expertise of students in other disciplines. We want to bring these students into the fold.” Environmental scientists, ecologists and other students can inform sustainable practices and find meaningful work with consulting firms and mine companies, she says.

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Lauman continues to investigate customizing seed mixes for mining reclamation efforts. A different project has her looking into desert broom as a useful species for revegetation at mining sites.