by Larry Campbell, retired exploration geologist, Darby
The proposed Sheep Creek Rare Earth mine at the head of the West Fork Bitterroot River presents many environmental and economic problems. One in particular deserves early attention.
The mineral actinolite is reported to occur in significant quantity at the Sheep Creek REE deposit. Actinolite is a mineral that can have several forms, including asbestiform. In that form it is “amphibole asbestos” and is closely related to tremolite asbestos that has caused the death of hundreds of people in Libby, MT. Amphibole asbestos is more toxic than other forms of asbestos.
To my knowledge there have been no reports of and no testing for asbestiform actinolite at Sheep Creek. In the interest of prudence, I believe it needs early testing due to its high toxicity to humans.
The Hamilton vermiculite mine area also contains significant amounts of actinolite. In 1993, after much exploration drilling activity and a Final Environmental Impact Statement to permit mining, the Bitterroot National Forest belatedly required a Supplemental FEIS to analyze and disclose human health impacts from possible asbestiform actinolite. The possible presence of asbestos there is still not adequately tested.
However, we can guess the presence of asbestiform actinolite there is likely. As the 2020 book “Roadside Geology of Montana” by university geologists states, “Several early attempts to mine vermiculite in the Skalkaho intrusion went poorly. While at one time that seemed unfortunate, now it’s clear that we narrowly escaped having another major [asbestos related] environmental disaster.”
I believe the public needs to insist that the BNF and MT DEQ require the mining company to pay for asbestos testing at the Sheep Creek REE mine site prior to any ground disturbing exploration activities.
Email concerns to Daniel.pliley@usda.gov and ask to be put on the notification list for news about the Sheep Creek mine project.