Reclamation research blossoms at Bingham Canyon

Rio Tinto Kennecott and Brigham Young University (BYU) researchers are trialling agriculture-based remediation methods at the Bingham Canyon copper mine in Utah, US.
Reclamation research blossoms at Bingham Canyon Reclamation research blossoms at Bingham Canyon Reclamation research blossoms at Bingham Canyon Reclamation research blossoms at Bingham Canyon Reclamation research blossoms at Bingham Canyon

Some 5,900 acres (2,388ha) of land at the mine has already been reclaimed

Six different projects are underway with innovations including engineered seed coatings, and the use of perennial grasses and native trees.

In June 2020, a group of students and professors from the BYU department of plant and wildlife sciences broke ground on four research projects on land areas surrounding the mine with the goal to increase plant diversity, stability and enhance the aesthetics of areas visible from Utah's Salt Lake Valley.

Matt Madsen, associate professor of plant and wildlife sciences at BYU, said: "The restoration can benefit Utah's land and community by bringing back native vegetation, improving the site for wildlife habitat, air quality and the viewshed here."

Gaby Poirier, managing director at Rio Tinto Kennecott, added: "This joint project is mutually beneficial for Rio Tinto Kennecott, BYU and our surrounding communities, and we hope this project will be a stepping-stone for future collaboration that helps improve reclamation work at other locations in Salt Lake City and more widely."

Alex Larson is one of two female BYU graduate students leading projects. Her Saints Rest biodiversity study is working to increase the diversity of plants on reclamation land by introducing shrubs and forbs that match the surrounding landscape, using a technique inspired by the process of how anti-epileptic medications work.

The team aims to engineer seed coatings that will improve seeding success on waste rock piles. To help meet this objective, they have developed a seed coating that enhances the germination of dormant seeds that may not otherwise germinate due to low moisture availability in the harsh rocky soils. This technology was evaluated on four different forb species and a shrub. 

Larson explained: "When anti-epileptic medications are taken, the compounds that treat the symptoms are embedded in a biodegradable polymer, essentially a biodegradable plastic, which dissolves after ingestion, so it slows the release of the medication and increases its effectiveness. We are applying this same method to seeds. We have a biodegradable biocompatible polymer coating embedded with a growth hormone wrapping the seeds we are planting. This coating will help increase the germination success on the site compared to what would exist naturally."

Fellow graduate student Holley Lund is spearheading the Yosemite Waterboxx study nearby. This project was designed to improve the viewshed of waste rock piles visible from the Salt Lake Valley by establishing native trees and shrubs that would help the hillslope look similar to areas not impacted by mining. They evaluate the use of a novel water capture and release storage device, called the Waterboxx, for improving the establishment of five different species. Waterboxx irrigation technology maintains moisture in the soil during dry periods of the year so that seedlings can establish in the rocky soils. By the end of the project, they will have planted 656 shrubs and trees.

Lund said: "Restoration has been done on this site before. It looks great during parts of the year; however, these particular species go dormant, turn brown and stand out from the native hillsides during other seasons. Our goal is to establish a woody species that will match the green textures of the surrounding mountainside, help with erosion and provide food for wildlife."

In 2021, the partnership will add two additional research projects to give a total of six focus areas. One will seek to understand how site characteristics influence revegetation efforts to help predict reclamation potential, improve reclamation efforts, and guide management decisions; the other will be to develop strategies for reclaiming rock piles without following the standard practice of adding a 1m cap of growth media.

Rio Tinto Kennecott said that 5,900 acres (2,388ha) of land at the mine has already been reclaimed, with 9,000 additional acres committed to be reclaimed. 

As part of its commitment to a more sustainable future, Kennecott decided in 2019 to permanently shut its coal-fired power plant and purchase renewable energy certificates, reducing the annual carbon footprint associated with its operation by as much as 65%. 

In 2020, Kennecott also became the first producer to be awarded the Copper Mark, the copper industry's new independently assessed responsible production programme, demonstrating it meets over 30 criteria for responsible environmental, social and governance practices.