EPA ID# IDD984666024
EPA Region 10

2nd Congressional District

Other Names:
Last Update: February, 2007

Hide details for Site DescriptionSite Description

The Triumph Mine Tailings Piles site is an inactive mine which consists of two large tailings piles, a waste rock pile, process areas, and underground workings with a draining adit. The site occupies 60 acres. The site is located in a relatively rural area of Blaine County, Idaho. The East Fork of the Wood River flows near the southern edge of the piles. From 1882 until 1957, the Triumph Mine processed silver, zinc, and lead ore. These operations involved crushing, grinding, and flotation activities. The slurry remaining from the flotation process was pumped into the upper pile from 1882 until 1930, and into the lower pile for the remaining years of site operations. EPA's preliminary site investigations in 1991 and 1992 showed elevated levels of heavy metals, such as lead and arsenic, in the piles and the former mine. These metals have migrated into the surrounding residential soil, ambient air, and neighboring wetlands. On several occasions, the State of Idaho and local health agencies conducted blood sampling of local residents for lead and urine sampling for arsenic. There were some signs of community exposure to arsenic levels above national averages; however, there were not signs of community exposure to lead above the national averages.

Site Responsibility: This site is being addressed through State and potentially responsible parties' actions.

NPL Listing HistoryDates
Proposed Date:05/10/1993
Removed Date:04/30/2003
Withdrawal Date:
Final Date:
Deleted Date:

Hide details for Threats and ContaminantsThreats and Contaminants

Media Affected: Air, Environmentally Sensitive Area, Groundwater, Soil & Sludges, Surface Water
The tailings piles, waste rock pile, and the mine contain elevated levels of heavy metals, such as lead and arsenic. These metals also have migrated into the surrounding residential soil, ambient air, neighboring wetlands, and surface water. People who inhale airborne tailings, or ingest contaminated soils, may be at risk.

Hide details for Cleanup ProgressCleanup Progress

April 30, 2003, EPA withdrew this site from the proposed National Priorities List. EPA does not believe that further response under Superfund is appropriate at this time. All major sources of risk have been mitigated. All contaminated yards, gardens, roads, waste rock, tailings, and other soil areas have either been excavated and replaced with clean soil, or capped with clean soil and a vegetative cover. The State and community strongly supported withdrawing the site from the proposed NPL, and EPA did not believe the mine water discharge warranted retaining the proposal to list the site on the NPL. Current status as of November 2005:
Mine Water from Tunnel
The mine adit plug was completed in 2004. The mine water has reached an elevation of 235-245 feet behind the adit plug. A seep survey was conducted in September 2006 to determine if there is any seepage from the plug. To date, no evidence has been found of seeps. The flow of water from the Triumph tunnel has remained stable. Water quality of the mine drainage is relatively good.

Groundwater Monitoring
Idaho Department of Lands continues to perform site water quality monitoring. Some of the shallow wells are dry during the fall testing due to the dry summer season and the lack of flow from the Triumph Tunnel. Manganese levels remain elevated from groundwater wells sampled down gradient from the Lower Tailings Pile. A comprehensive evaluation of groundwater quality is in the initial planning phase.

Community Protection Measures
The Idaho Department of Environmental Quality and the Idaho Department of Lands continue to work with impacted residential property owners on a conservation easement. Another possible option is an overlay district that could be established by the Blaine County Commission.

Lead Agency and Ovesight
EPA and the State of Idaho signed a Memorandum of Agreement to defer oversight of this site to the State of Idaho. The site was addressed in a long-term remedial phase focusing on the cleanup of the entire site.

Under the oversight of the State of Idaho, the potentially responsible parties (PRPs) conducted a site Remedial Investigation (RI) to determine the nature and extent of contamination, and Feasibility Study (FS) to evaluate remedial alternatives. The RI/FS was completed in March 1998. The selected remedy included capping the tailings piles, waste rock pile, and process area; removal of contaminated soils in residential yards to a depth of one foot; removal of discrete piles of visible tailings in the wetland; plugging the mine portal with a contingency for treatment if deemed necessary. The cleanup began in September 1998 and was completed in summer 2004.

Hide details for Regional ContactsRegional Contacts

SITE MANAGER(S):Mark Masarik
PHONE NUMBER:208-378-5761
PHONE NUMBER:208-378-5761
Information pertaining to this site is housed at the following location(s):
Hailey Public Library (Administrative Records)
7 West Croy Street
Hailey, Idaho 83333
Phone: 208-788-2036
Fax: 208-788-2924