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EPA in Montana

Public Notice: Sixth Five-Year Review for the Libby Ground Water Contamination Superfund Site Complete

Publish Date: 07/27/2020


EPA, in cooperation with the Montana Department of Environmental Quality (DEQ), has conducted the sixth five-year review of the Libby Ground Water Contamination Superfund site in Libby, Montana. The purpose of the five-year review is to make sure that the cleanup actions completed to date are adequately protecting human health and the environment.

The site is a former lumber mill and wood-treating operation located on Highway 2 in the City of Libby, Montana. EPA added the site to the National Priorities List (NPL) in 1983. Historical operating practices and the release of wood-treating fluids at the site resulted in impacts to soil and the underlying groundwater. The site is broken into two Operable Units (OUs). OU1 consists of the alternative drinking water supply for the town of Libby. OU2 consists of the affected environmental media, including contaminated soils, upper aquifer groundwater and lower aquifer groundwater.

The recent review, completed in July 2020, concluded that the remedies for OU1 and OU2 are protective in the short term.

For OU1 long term protectiveness, the remedy must include additional institutional controls to prohibit groundwater use outside of the city limits.

For OU2 long term protectiveness, the remedy must include: additional institutional controls to restrict land use and activities that may interfere with remedial activities in all areas with remaining waste; a decision document modifying groundwater ARARs; assessment of risk-based cleanup levels and residual soil contamination; and additional modification of the remedy as needed to meet the remedial action objectives.

Questions? Please contact:

Beth Archer (ORA-PA-C)
Community Involvement Coordinator
U.S. EPA Region 8
1595 Wynkoop Street
Denver, CO 80202-1129
(303) 312-6611 or
(800) 227-8917 ext. 312-6611 (toll free in Region 8 states only)

Additional site information is available at:

Lincoln County Health Department
418 Mineral Ave.
Libby, MT 59923

EPA Superfund Records Center
1595 Wynkoop Street
Denver, CO 80202-1129
(303) 312-7273

Or online at