EPA Region 10 Lemhi County Town of Lemhi
2nd Congressional District Other Names:
Last Update: May, 2010
The Blackbird Mine site encompasses approximately 830 acres of private patented mining claims and 10,000 acres of unpatented claims within the Salmon National Forest. The site is located 20 miles west of Salmon, Idaho and is in the Panther Creek drainage basin, which drains into the Salmon River. Big Deer Creek and Blackbird Creek drain into Panther Creek. Since the late 1800s, several companies have mined cobalt and copper on the site with both mine tunnels and open-pit methods. The current owner, the Noranda Mining Company, ceased operations in 1982. Mine tunnels, waste rock piles, and the open pit are located at the headwaters of Meadow and Bucktail Creeks which drain into Big Deer and Blackbird Creeks. There is a tailings impoundment located on the West Fork of Blackbird Creek and tailing deposits located along Blackbird Creek from transport of tailings to the West Fork tailings impoundment or direct discharges of tailings into the creek. The waste rock piles alone are approximately 4 million cubic yards. Investigations have shown that acid rock drainage and leachate from the tunnels, waste piles and tailings have contributed to the poor water quality in local creeks. High levels of heavy metals such as copper, cobalt, and arsenic are present in surface water and/or sediments downstream from the site. The copper levels exceeded EPA's Fresh Water Ambient Water Quality Criteria. Arsenic in soils located along the banks of Blackbird Creek and Panther Creek downstream of the mine may pose a potential risk to humans. The Snake River sockeye spring/summer Chinook salmon, Snake River steelhead and bull trout, listed as threatened or endangered under the Endangered Species Act, are threatened by the poor water quality.
Site Responsibility: This site is being addressed through federal and potentially responsible parties' actions.
NPL Listing History
Threats and Contaminants
Media Affected:Groundwater, Soil & Surface Water
Surface water and sediments are contaminated with high levels of heavy metals such as copper, cobalt and arsenic. Groundwater and surface water are primarily contaminated with copper and cobalt. Sediments and soils are primarily contaminated with copper, cobalt and arsenic. Site studies have shown that acid rock drainage from tunnels and waste piles have contributed to the poor water quality of local creeks. This water quality affects local aquatic life, including the Snake River spring/summer Chinook salmon and other endangered or threatened species. People who come into direct contact with or ingest contaminated sediments or soils could be at risk.
This site is being addressed by early actions and a long-term remedial phase focusing on the cleanup of the entire site.
In 1983, the Idaho Attorney General filed a natural resources damage suit against current and two previous site owners/operators for alleged damages to State surface water and groundwater. The suit was settled in 1995. In 1993, the potentially responsible parties (PRPs) initiated early actions to stabilize the West Fork Tailings Dam by diverting the West Fork of Blackbird Creek to prevent failure of the tailings impoundment. In late 1994, the PRPs, under EPA supervision, began an investigation to determine the nature and extent of site contamination. Results of this investigation, scheduled to be completed in 2002, will be evaluated to determine the most effective remedy for final site cleanup.
In late 1994, the PRPs began investigations and analysis of alternatives for an early removal action on major sources at the mine that release metals to surface water. In 1995, the PRPs began a removal action to address the waste rock piles, underground mine tunnels, the open pit and impacted groundwater and surface water at the mine. The action includes relocating some of the waste rock piles, capping waste rock, construction of a water storage dam and a water diversion dam, expansion of the existing water treatment plant and interception of ground water and surface water for treatment, and were completed in November 1998.
The West Fork of Blackbird Creek diversion channel and the early removal action on sources at the mine have helped to support restoration of water quality downstream of the Blackbird Mine site while site studies are being conducted.
Another removal action was conducted at the Panther Creek Inn (PCI) property, located about 7 miles east of the Blackbird Mine where Blackbird Creek and Panther Creek meet.
The PCI property is comprised of an inn, a cabin and adjacent campgrounds. Investigations conducted in the past identified elevated concentrations of arsenic in soils which pose a potential risk to humans. The soils were removed to a minimum depth of one foot and replaced with clean fill. The removal action also included construction of three sediment ponds along Blackbird Creek and removal of contaminated overbank deposits (sediments and soils) that are susceptible to erosion along Blackbird Creek. This will reduce the potential for recontamination of the PCI property. This removal action was completed in August 1999.
Another removal action was completed in October 2001 to address potential risks to humans from arsenic found in soils along the bank (overbank deposits) in some locations along Panther Creek. Contaminated soils were removed to cleanup levels or the water table, whichever comes first, and then replaced with clean fill.
A remedial action is underway to address potential risks to aquatic life from remaining releases of metals into surface water from the mine site. Construction activities to address releases of metals to surface water have been underway since 2003 and are projected to be complete in 2012. Removal of contaminated soils along the banks of Panther Creek to address potential human health risks were completed as part of the remedial action. However, during the spring of 2008 and 2009 high water in Blackbird Creek resulted in contaminated sediments and tailings to be mobilized and redeposited along the banks of Panther Creek at levels that pose a potential human health risk. Additional removal of the contaminated soils along the banks of Panther Creek occurred in 2009 and will continue in 2010. Additional measures are being taken to stabilize and remove contaminated sediments along Blackbird Creek to reduce the potential for remobilization during high flow events. These actions are planned to be completed in 2010.