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, 9/19/03
ERRS Response Manager arrived at site to scope project and identify local equipment. Subcontract archeologists (Northwind Environmental) arrive to begin archeological survey of areas that will be disturbed and identify areas that need to be protected.
Saturday, 2/20/03
Archeologists continue archeological survey work. 4 ERRS equipment operators and 1 field clerk mobilize to site.
Sunday, 2/21/03
Equipment delivered to site: 2 40-ton haul trucks; D8 bulldozer, D6 bulldozer, 966E wheel loader. 3 additional ERRS equipment operators/laborers mobilize to site. Archeologists continue archeological survey work. ERRS begin clearing of repository area and begin improvement of access road and staging area.
Monday, 2/22/03
EPA OSC mobilize to site. START project engineer mobilize to site. Personnel on site:
EPA OSC - 1
Forest Service OSC - 1
START Project Engineer - 1
ERRS contractor personnel - 9
Archeologist subcontractor - 2
ERRS continue widening and improving approximately 10,000 feet of road to mine site to allow 14' wide haul trucks to access safely. Archeologists finish archeological survey.
Tuesday, 2/23/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Road improvements progressed 2,000 feet to the vicinity of the debris flow. Rock was taken from talus slope and placed on constructed roads. The debris flow area turned out to be saturated and would not support heavy equipment. 2 office trailers and generator delivered to site. 300E excavator delivered to site.
Wednesday, 2/24/04
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
Excavated and stockpiled muck where debris flow crossed road. Diverted unnamed tributary to it's original channel so that it doesn't cross road. Continued road improvement 1,500 feet beyond debris flow to the switchback. Continued placing rock from talus slope on constructed roads. Fuel storage tank delivered to site. Constructed secondary containment for fuel storage.
Thursday, 9/25/03
Personnel on site:
EPA OSC - 1
FS OSC - 1
START Project Engineer - 1
ERRS contractor - 9
EPA and FS OSCs conducted site visit for Forest Supervisor and DEQ Regional Administrator. ERRS continued road improved addional 500 feet. Scoped what it'll take to divert creek around tailings pile and reviewed cultural features to be protected. Set repeater up on ridge to establish communications across site, from tailings pile to staging/office area.
Continue punching road through to access tailings pile. Should take another 3-4 days. Will complete creek diversion above tailings pile within a couple days. Finalize repository design with Project Engineer and FS OSC. Improve BMPs along constructed road near creek.
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.
|
