Vermiculite was mined near Libby, Montana from the 1920s until 1990. That vermiculite was contaminated with Libby Amphibole asbestos, a toxic form of asbestos fiber. EPA added the site to the Superfund National Priorities List in October 2002 and declared a Public Health Emergency in 2009 to help victims of asbestos-related disease access federal health care.
Asbestos is the only contaminant of concern at this site. It has been found in soil and buildings across multiple areas, including residential and commercial properties, highways, a screening plant, an export plant, a lumber mill, and a railroad corridor. The primary health risk comes from breathing dust from dirt and vermiculite that contain asbestos fibers. EPA has determined that human exposure is not currently under control, meaning an unsafe level of contamination has been detected and people could still be exposed.
The site is divided into eight operable units. Cleanup is complete at several of them. The Export Plant, Screening Plant, Stimson Lumber, Burlington Northern Railroad, and State Highways units have all finished remedial action and been partially deleted from the National Priorities List. The Remedial Sitewide unit finished remedial action in June 2020 and is estimated for partial deletion between September and November 2027. Over 2,600 homes and businesses in Libby and Troy have been cleaned, and more than one million cubic yards of contaminated soil have been removed. Air asbestos levels in downtown Libby are now nearly 100,000 times lower than during mining. The former mine unit, called Operable Unit 3, is still under investigation. EPA expects to release a proposed cleanup plan for that area in 2027 and select a final remedy after a public comment period. Wildfire preparedness at the mine area is an active concern because firefighters face higher asbestos exposure during wildfire suppression.
Redevelopment is already under way in cleaned areas. Riverfront Park opened in 2013 and hosts an annual blues festival. A golf course, recreational trail, and fishing pond have also been developed on cleaned land. As of December 2024, 366 businesses operating at the site employ about 2,572 people and generate roughly $334.8 million in annual sales.
Community members who own property in the area should contact the Lincoln County Asbestos Resource Program at (406) 291-5335 before any construction, renovation, or excavation. Property owners outside the site boundary who have ZONOLITE brand vermiculite attic insulation may be eligible for up to $4,125 in reimbursement through the Zonolite Attic Insulation Trust. The most recent five-year review was completed in June 2025, with a public meeting held in July 2025. Fact sheets, newsletters, and meeting presentations are available through EPA.
