The Harmony Mine is a former copper mine and milling facility, which operated between 1916 and 1931. The Site has been inactive since 1931. The property consists of approximately 330 acres of private patented land surrounded by the Salmon-Challis National Forest (SCNF), and includes a large tailings pile which lies approximately 1/3 on the private land and 2/3 within the SCNF. The Site tailings pile is at approximately 7,000 feet elevation. The South Fork of Withington Creek originates upstream of the tailings pile and flows through the existing tailings pile. Withington Creek flows into the Lemhi River approximately 8 miles downstream of the Site. The Lemhi River flows an additional 10 miles to its confluence with the Salmon River.
The tailings pile is not contained and has partially collapsed into the stream channel. It appears that over one-half of the volume of material in the original tailings pile has been released, via failure of the tailings dam and stream erosion of the tailings pile. An estimated 10,000 to 20,000 cubic yards of tailings remain at the original tailings pile area.
The Site is located near Baker, northeastern Lemhi County, approximately 15 miles southeast of Salmon, Idaho. The property is near the headwaters of Withington Creek. Access to the Site is via an unimproved extension to the Withington Creek road, approximately 9 miles from State Highway 28.
In August 2003, the Withington Creek forest fire destroyed the vegetative cover in the upper Withington Creek drainage at and above the Site. There has been one significant rain event in the drainage since the fire, which has already caused erosion and washouts in various locations around the mine Site. It is likely that any subsequent high intensity storm event or high volume runoff this coming Spring could result in massive failure of the remaining tailings pile.
EPA and the USDA Forest Service are taking joint CERCLA Removal action to remove the existing tailings pile to a secure repository approximately 1 mile below the mine site on land admistered by the Forest Service. Forest Service has provided approval for siting of the joint EPA/Forest Service repository.
Friday, 9/26/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Archeologist subcontractor - 1
Continued road improvement to mine site. Cleaned out diversion ditch above tailings pile for placement of creek diversion pipe. Cleared repository area of timber. Conducted areological oversight of road construction adjacent to historically significant can dump area.
Saturday, 9/27/03
Personnel on site:
START Project Engineer - 1
ERRS contractor - 9
Approximately 2000 feet of road was improved today, including the road in the vicinity of the old mill building. 220 feet of 12-inch diameter pipe was staged in the diversion channel.
Sunday, 9/28/03
No site activity.
Monday, 9/29/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Archeologist subcontractor - 1
Installed 220 feet of 12" diversion pipe in the upper diversion channel. The remaining 360 feet of pipe was delivered late in the day and will be installed tomorrow. Felled trees and prepared bottom surface of approximately 80 feet by 300 feet in the repository area.
Tuesday, 9/30/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Installed remaining diversion pipe and diverted creek around and above tailings pile to dry out tailings so that they can be removed. Completed road construction to mine site.
Wednesday, 10/1/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Archeologist subcontractor - 1
Constructed road from mine site to access tailings pile. USFS crew surveyed constructed repository area. Received water truck on site.
Thursday, 10/2/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Archeologist subcontractor
EPA and FS OSCs conducted site visit for reporters from Salmon newspaper. Began hauling tailings from mine for placement into constructed tailings pile. Received second excavator and third 40-ton haul truck on site. Installed BMPs along toe and downgradient of repository. Spilled approximately 15 gallons of transmission oil onto haul road and in repository area when a line broke on haul truck. Reported spill to Idaho State Comm, and received approval from Idaho DEQ and from Forest Service to place excavated contaminated soil into tailings repository.
Haul tailings to repository. Estimate production rate of approximately 1,000 cy/day. Construct large sedimentation pond below tailings pile to capture runnoff from rain/storm events during construction.
Completion of the removal as designed is contingent upon seasonally mild weather. Early severe winter weather could force alternate plan for attempting to secure at least a portion of the tailings in place.
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