EPA gives update on asbestos cleanup efforts and plans
The US. Environmental Protection Agency (EPA) has made significant progress in recent years understanding the extent of Libby Amphibole asbestos (LA) contamination at and near the former vermiculite mine. The purpose of this article is to provide an update on which forest-use activities pose ongoing risk, which don’t and how investigation results are being used to make decisions in this area, also known as Operable Unit 3 (OU3) of the Libby Asbestos Superfund Site.
As part of the Remedial Investigation and Human Health Risk Assessment for the Libby Superfund site (EPA, 2015), EPA did extensive sampling of air, soil, mine waste, tree bark, duff and other environmental media within OU3. We also tested the air in areas known to be contaminated in OU3 during recreation, logging, firefighting and other activities to determine the potential for human exposures.
After years of studying a large 40,000-acre area including the former mine and surrounding forest, EPA and our partners — U.S. Forest Service, Montana Department of Environmental Quality and Montana Department of Natural Resources — have identified an area of about 10,000 acres surrounding the mine that has the highest levels of contamination. EPA is currently in discussions with W.R. Grace to determine the best methods to reduce contamination and limit exposures in this area.
EPA, our partners and W.R. Grace will be evaluating different treatment technologies that can be implemented in different areas of the forest to reduce exposures to LA in soil, duff and tree bark. Some of these technologies may include removal of contaminated duff/soil, forest thinning for fire management and covering the contaminated duff/soil with slash, mulch or gravel. There may also be management techniques such as logging in the wetter months of the year rather than drier months to reduce the potential for LA-laden dust to be generated during logging activities and result in excessive exposures.
Since higher asbestos exposures have been detected during activity based sampling for fire suppression and mop-up activities, it is important to reduce the potential for large, persistent fires in the areas of high LA contamination near the mine. This is why we have a joint plan in place with Lincoln County and other local, state and federal agencies to ensure an expedited response in the case of a wildfire in the vicinity of OU3. Additionally, W.R. Grace is beginning efforts this summer to build fire-breaks to reduce the likelihood that fire would spread and clearing roads so there is better access to support a quick response. These efforts are welcome as we work together to define the long-term remedy for OU3 that will ensure protection for firefighters and loggers.
It should be noted that the human health risk assessment determined recreational activities in OU3 such as hiking, camping, ATV riding, and fishing are not considered hazardous with regard to LA exposures. The only exception to this would be hiking along Rainy Creek and digging in the mine by rock hounds and trespassers. Residents and visitors should continue to refrain from trespassing on the mine property owned by W.R. Grace.
EPA expects to share a proposed cleanup plan for OU3 by the end of 2019. We look forward to working with the community on plans for long-term site management. As always, EPA welcomes questions and comments from the community regarding the Superfund activities in and around Libby and Troy. Please don’t hesitate to contact me at mckean.deborah@epa.gov or call EPA’s Libby office at 406-293-6194.
Deborah McKean is senior toxicologist for EPA Region 8’s Operable Unit 3 Study Area for the Libby Asbestos Superfund Site.