Flooding in Montana Raises Concerns Over Asbestos and Water Safety

A deluge of warm-weather precipitation in Montana triggered record-breaking streamflows, raising concerns over potential asbestos contamination and drinking water safety in Libby.

December 13, 2025

Record-breaking streamflows in Montana’s northwesternmost county have caused severe flooding along Libby Creek and the Yaak and Fisher rivers. This flooding, aggravated by heavy rainfall and warm temperatures, washed away infrastructure and raised concerns about water supplies and asbestos contamination from old mining waste. Communities are worried about the potential spread of toxic soil from a local Superfund site, and the safety of their drinking water is in question.

Inquiries to environmental officials confirmed no immediate asbestos-related risks, yet residents should boil water and may find vermiculite post-flood. Asbestos, a harmful byproduct of vermiculite, can cause lung diseases if inhaled. The contamination originates from a former W.R. Grace mine, now part of an established Superfund site. Most areas have been remediated, but some unaddressed zones still pose a threat.

BUT FIRST, WHAT IS ASBESTOS AGAIN?

Asbestos fibers in vermiculite ore are toxic when airborne, causing lung issues and cancer. The U.S. EPA declared Libby a Superfund site in 2002 due to lingering asbestos from W.R. Grace’s operations, which prompted a public health emergency in 2009.

WHERE IS THE FLOODING HAPPENING RELATIVE TO THE SUPERFUND SITE?

Flooding, predominantly south of Libby and Troy, overlaps the Superfund site’s boundary, raising contamination concerns. The closed vermiculite mine lies northeast of Libby, slightly away from major flooding. The DEQ and W.R. Grace, which owns the site, report no current structural issues. The EPA also noted no flooding impacts on the Superfund site.

SO, WHAT ARE ENVIRONMENTAL REGULATORS CONCERNED ABOUT?

Environmental officials are focused on potential asbestos exposure from displaced vermiculite. Although immediate health risks from asbestos are minimal while submerged, flooding could reveal previously unseen vermiculite, which becomes hazardous when dried. Inspections and remediation will occur if mine waste is discovered post-flood.

Residents finding vermiculite should contact the Lincoln County Asbestos Resource Program for removal. The shiny, mica-like material should be safely transported to the designated landfill.

IS IT SAFE FOR LOCAL RESIDENTS TO DRINK TAP WATER?

The DEQ has advised Libby residents to boil water after floods affected water clarity, complicating treatment. The advisory remains until the water meets the Safe Drinking Water Act standards. Local sources assert the issue is unrelated to asbestos but due to clay bank erosion, with turbidity levels dropping but still under observation.

Libby’s water treatment staff confirm no asbestos contamination, citing “other contaminants” as the issue due to the storm runoff affecting water quality. Residents are encouraged to use boiled water for consumption and hygiene until further notice.