Superfund Information Systems: Site Profile

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Gold miners discovered vermiculite in Libby in 1881. In the 1920s, the Zonolite Company formed and began mining the vermiculite. In 1963, W.R. Grace bought the Zonolite mining operations. The mine closed in 1990.

While in operation, the Libby mine may have produced 80 percent of the world's supply of vermiculite. Vermiculite has been used in building insulation and as a soil conditioner. Unfortunately, the vermiculite from the Libby mine was contaminated with a toxic and highly friable form of asbestos called tremolite-actinolite series asbestos, often called Libby Amphibole asbestos (LA). EPA’s investigation determined LA to be present in air (indoor and outdoor ambient), vermiculite insulation and bulk materials, indoor dust, soil, water, animal and fish tissue and various other media.

In 1999, EPA responded to citizen, local government and media concerns regarding possible exposure to asbestos from the nearby vermiculite mine. EPA’s Removal program began conducting investigations and removal actions to address LA beginning in 2000. EPA placed the site on the Superfund program’s National Priorities List (NPL) in October 2002. In 2009, for the first time in the history of the agency, EPA declared a Public Health Emergency in Libby to provide federal health care assistance for victims of asbestos-related disease.

EPA has made significant progress in reducing the amount of LA in the area. This has reduced the chance of contact with LA, which is known to cause lung disease and other breathing problems. The amount of LA in air in downtown Libby is now nearly 100,000 times lower than when the vermiculite mine and mill were operating.

Investigation and cleanup of the site was completed in 2018 with the exception of the former vermiculite mine and forested areas (Operable Unit 3).

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What Has Been Done to Clean Up the Site?

In December 2014, EPA completed a rigorous scientific review of toxicity values and finalized a risk assessment a year later. The final risk assessment confirmed that EPA’s indoor and outdoor cleanups have effectively managed risk from exposure to asbestos.

As of November 2018, EPA had completed cleanup of over 2,600 properties located within Libby and Troy and had investigated over 7,600 properties within the Superfund site. This means that EPA has removed more than one million cubic yards of contaminated soil.

Cleanup is complete at all schools and parks, the former vermiculite processing plants and other contaminated public areas. EPA has safely removed well over one million cubic yards of asbestos-contaminated waste from major source areas and structures. Contaminated soils are disposed of at the former vermiculite mine. Contaminated construction debris is placed in a specially designed landfill cell.

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What Is the Current Site Status?

Site cleanup is being addressed through federal, state and potentially responsible party (PRP) actions.

The site consists of eight areas, referred to by EPA as operable units (OUs). These OUs address the following areas:

OU1: The former Export Plant and the Highway 37 embankments. The major components of the long-term remedy, selected in May 2010, included containment, removal and institutional controls. EPA completed remedial action in July 2013. Operation and maintenance activities are ongoing.

OU2: Areas impacted by contamination released from the former Screening Plant. These areas include the former Screening Plant, the Flyway property, the Highway 37 right‐of‐way next to the former Screening Plant and/or Rainy Creek Road and privately-owned properties. The major components of the long-term remedy, selected in May 2010, included removal, containment and institutional controls. EPA completed remedial action in May 2012. Operation and maintenance activities are ongoing. Partially deleted in April 2019.

OU3: Property in and around the former mine impacted by Libby Amphibole asbestos, including a tailings dam and impoundment of vermiculite mine waste, the Kootenai River, Rainy Creek and Rainy Creek Road, and surrounding forested areas. EPA completed the remedial investigation in 2016 and we expect to complete a feasibility study in 2019. EPA is currently evaluating different treatment technologies that could be implemented to reduce exposures to LA in soil, duff, water, sediment and mine waste. Since higher exposures to LA have been observed during wildfire suppression and mop up activities, EPA works closely with the US Forest Service, WR Grace, state and local partners, and other stakeholders to prepare for and prevent wildfires. We are also working closely with WR Grace, and state and local partners to address concerns about degradation at the tailings dam, also known as the Kootenai Development Impoundment Dam.

OU4: Residential, commercial, industrial (not associated with former W.R. Grace operations) and public properties, including schools and parks in and around Libby, or those areas that have received material from the mine not associated with W.R. Grace operations. EPA has completed investigations at more than 6,400 properties and cleanups at more than 2,400 properties.

OU5: The former Stimson Lumber Company property. This approximately 400 acre industrial park is bound by the high bank of Libby Creek to the east, the BNSF railroad to the north and residential/commercial/industrial property in OU4 to the south and west. The area is currently occupied by various vacant buildings as well as multiple operating businesses. The remedial investigation was completed in 2013 and removals were completed where needed. Remedial action was completed in 2016. Operation and maintenance activities are ongoing.

OU6: Owned and operated by the BNSF railroad, these properties encompass 42 miles of rail line, rights-of-way, and rail yards. EPA anticipates no further cleanups within OU6. Institutional controls will be required to ensure that the remedy remains protective.

OU7: All residential, commercial and public properties in and around the City of Troy, Montana, about 20 miles west of downtown Libby. As of January 2016, EPA has completed investigations at 1,400 properties and cleanups at more than 200 properties.

OU8: United States and Montana State Highway transportation corridors, these properties include 30 miles of U.S. Highway 2, Montana Highway 37, and Farm to Market and River Roads. EPA anticipates no further cleanups within OU8. Institutional controls have been established to ensure that the remedy remains protective. Operation and maintenance activities are ongoing.

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Emergency Response and Removal

EPA’s Removal program began conducting emergency responses to address LA in 2000. EPA has removed major sources of LA in and around the communities of Libby and Troy, investigated thousands of properties and has conducted removals at numerous private homes and properties.

Removals were conducted at the former export plant, former screening plant, Riverfront Park and boat ramp, rail yard, golf course, schools and school yards, creek banks and other public areas. EPA has removed more than one million cubic yards of impacted soil and more than 30,000 cubic yards of contaminated building material. EPA has also used our emergency response authority at the former vermiculite mine and forested areas (OU3) to support the U.S. Forest Service and local and state partners with wildfire preparedness since firefighters are at risk of higher exposures to LA during wildfires.

Since 2016, when EPA signed a Record of Decision for cleanup in the communities of Libby and Troy, cleanup work has been conducted as remedial action. At this point, EPA doesn’t anticipate future removal actions unless they are needed for interim actions at OU3. EPA anticipates sharing a proposed cleanup plan for forested areas of OU3 in 2019.

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