The U.S. EPA announced in November 2018 that asbestos cleanup had been completed on residential and commercial properties in Libby, Montana. The asbestos contamination of the village and the mining site nearby occurred from around 1910 to 1990 when vermiculite ore was mined as an insulation product and for plaster and masonry mixes. Small amounts of tremolite asbestos were in the ground and were mined along with the vermiculite, contaminating it with asbestos.
The investigation and cleanup of asbestos contaminated vermiculite insulation at the mine and in Libby started around 20 years ago. During that time around 2,600 properties in the area have been cleaned up.
The on going work in the Libby area will focus on monitoring to ensure that the cleanup has been working correctly and be monitored by an oversight committee called the Libby Asbestos Superfund Oversight Committee. Eventually the EPA will hand over control to the state of Montana Department of Environmental Quality and the local county government.
More information is available at on the EPA web pages for the Libby cleanup:
The Libby vermiculite, which was sold under the brand name Zonolite, was added as attic and wall insulation in close to 1 million homes around the country. The Wisconsin Department of Health Services has additional information about potential asbestos hazards in vermiculite: https://www.dhs.wisconsin.gov/air/vermiculite.htm.
In addition, the WR Grace company has set up a reimbursement program for property owners that want to have the vermiculite insulation removed from their home: