Hecla Greens Creek Mine just got the green light for an expansion that could extend mine operations for up to another 18 years. The U.S. Forest Service officially permitted the project on Admiralty Island on Thursday.
After nearly five years of planning and public review, Greens Creek is now allowed to build more storage for tailings — the ground-up rock that’s leftover after the extraction of valuable metals like gold, zinc and silver.
Greens Creek is the nation’s largest silver mine and one of Juneau’s most prominent and profitable employers. The expansion approval comes with new requirements for environmental oversight.
According to Forest Service geologist Matthew Reece, a number of individuals and environmentalists have expressed concern about the mine’s potential to contaminate the environment in Admiralty Island National Monument where it operates.
“One of the things that we heard loud and clear was that folks really wanted to see a concrete plan for mitigation and monitoring of fugitive dust leaving the tailings facility,” he said.
At Greens Creek, waste rock is temporarily stored in large outdoor piles before it is moved underground for long-term storage. That means there’s potential for fine particles containing heavy metals to blow off into the surrounding forest and waterways. That’s known as fugitive dust.
The mine does have measures to mitigate fugitive dust already, but moving forward they have to implement a new plan to do even more about it.
New ideas proposed in the plan include misting the tailings piles with water to weigh down dust particles and reducing the amount of exposed tailings during the winter months, when blustery conditions might spread dust further. The Forest Service has even committed to measuring the dust to make sure the mine is cutting down on how much spreads.
Another new piece of environmental oversight is the establishment of a collaborative monitoring panel, which will bring together representatives from the Forest Service, Hecla, state and federal environmental agencies and the nearby Tribe and Tribal Corporations of Angoon and Kootznoowoo, Inc.
Reece says the group is meant to introduce more transparency into the mine’s potential environmental impacts, especially near sensitive environments that communities like Angoon rely on for subsistence.
“The idea is to have a collaborative working group reviewing and making recommendations for potentially additional monitoring. This is going to be a pretty heavy lift,” he said.
Reece said the Forest Service will be working over the next couple of months to bring stakeholders together and come up with a more specific plan about what the panel will work on. In the meantime, Greens Creek is working to acquire the necessary permits to break ground sometime next year.