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% 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 form of naturally-occurring asbestos called tremolite-actinolite asbestiform mineral fibers.
In response to local concern and news articles about asbestos-contaminated vermiculite, the U.S. Environmental Protection Agency sent an Emergency Response Team to Libby, Montana in late November 1999. The Team immediately began collecting information. Both state and federal government issued an urgent response that can be seen on video here.
EPA's first priority was to assess the current risk to public health from asbestos-contaminated vermiculite in Libby. Next, the Agency began taking necessary actions to reduce this risk.
In December 1999 EPA began collecting samples - nearly 700 - from air, soil, dust and insulation at homes and businesses. Indoor air sample results were released in January - first to property owners and then to the media and general public. EPA also moved immediately to locate areas in and near Libby that were likely to have high levels of contamination such as two former vermiculite processing facilities.
EPA also looked at general asbestos exposures in the community and at health effects seen in people who had little or no association with the vermiculite mine in Libby. EPA worked closely with local, state and federal agencies to understand how people might come into contact with asbestos-contaminated vermiculite and what can be done to prevent future exposures - in Libby and elsewhere.
Libby was added to EPA's National Priorities List in October 2002.
EPA established a program to inspect all properties in Libby. Approximately 3500 properties were inspected in 2002 and 2003. Over 12,000 soil samples were collected and analyzed and the results are being sent to property owners.
As of 2006, the former vermiculite processing plants and other public areas have been cleaned up. Clean ups have also been completed at a total of 794 residential and commercial properties. EPA expects to complete at least 170 cleanups is 2005.
Based on current information, EPA estimates that 1200-1400 residential and business properties will need some type of cleanup. The total number depends upon the final cleanup standards set by EPA. EPA intends to propose these standards later this year.
Contact the EPA Information Center (406-293-6194) for the latest information on the work being done by the Environmental Protection Agency in Libby. The staff will answer your questions or direct you to the appropriate resource. You can find out if your property has been screened for asbestos and if any cleanup work was done. Also, you can see samples of vermiculite in various forms and you can pick up a number of informative fliers and brochures.
Since November, 1999, EPA has cleaned up the major source areas of contamination around town. EPA is now cleaning up smaller sources found in a variety of places such as around homes and businesses. EPA conducts stringent clearance sampling after cleanup and has begun some targeted sampling to measure the effectiveness of cleanup several months later. EPA is also working on long-term plans to ensure that the cleanup remains protective and human health risks continue to be reduced over time. EPA's ongoing cleanup efforts continue to make Libby a safer place to live, work, and visit.
Until the cleanup is finished, disturbance of vermiculite is the most likely source of exposures to asbestos. Learn what it looks like here and if you find it on your property, don't handle it!