Site Location
The Blue Ledge Mine site (Site) is an abandoned copper mine situated on patented private land within the Rogue River National Forest on United States Forest Service (“USFS”) Road 1060. It is approximately 35 acres in size. The geographic coordinates of the Site are 41° 57' 36" N latitude and 123° 07' 51" W longitude in Township 3 S, Range 9 E, on the Dutch Creek, CA (7.5-minute) topographic quadrangle..
The Site is approximately 4,800 feet above sea level on a north slope, in close proximity to the summit. Approximately four residences that comprise the community of Joe Bar, California, are located 1 mile downstream of the Site.
The Blue Ledge Mine was one of the largest mining operations ever undertaken in the southwestern Oregon area (Kramer 1999 in Environment International 2002). Over two miles of underground excavations and connections were developed to mine massive sulfide deposits rich in copper, zinc, gold and silver. Historically, the economic value of the mine lay in extraction of copper and zinc.
Tailings and waste rock have been dumped onto the steep slopes of the Site; the disposal area can be viewed easily from USFS Road 1060. The waste pile may be as deep as 30 feet in some places and is estimated to be between 30,000 and 40,000 cubic yards in volume. A stream course cuts down the mountainside through the waste pile. The stream is an unnamed tributary to Joe Creek. The tributary travels approximately 1,200 feet and descends 800 vertical feet to its confluence with Joe Creek. A log tailings dam, approximately 30 feet wide and 6 feet in height, intersects the stream course, preventing the tailings and waste rock from collapsing and blocking the tributary completely. Some waste material has already penetrated the dam. The dam shows signs of significant decay and is in danger of collapse.
Stream flows do bypass the dam and surface water contact with the waste pile has resulted in acid mine drainage (“AMD”) and acid rock drainage (“ARD”) in the tributary. An orange discharge leaches from the pile into the tributary. In addition, precipitate or “yellow boy”, and “ferricrete” indicative of AMD can be observed at the confluence of the tributary and Joe Creek.
Removal Site Evaluation
Surface water sampling conducted by the U.S. Forest Service (USFS) in September 2000, April 2001 and August 2001, documented releases of heavy metals, including cadmium, copper, iron, lead, and zinc to the tributary stream and to Joe Creek. Concentrations of cadmium and copper exceeded federal and state Maximum Contaminant Levels (“MCLs”) both in the tributary and Joe Creek. Surface water samples collected from Elliott Creek in April 2001 illustrated dramatic increases in copper, and zinc concentrations after the confluence with Joe Creek; suggesting that the Site is releasing dissolved heavy metals to the Joe Creek and that these dissolved metals are being transported to Elliott Creek.
Sampling results were also compared to Aquatic Life Criteria (“ALCs”). Cadmium, copper, and zinc concentrations exceeded their respective ALCs, at one or more sampling location, in all of the 3 sampling events.
In October 2004 USFS contacted the Emergency Response Section and requested assistance in mitigating actual releases of hazardous substances. U.S. EPA and the Superfund Technical Assessment and Response Team (START) conducted a Site screening event followed by a removal assessment at the Site. Screening samples were collected on May 4, 2005, and identified lead and arsenic as the contaminants of concern (“COCs”).
Statistical analysis of sampling results from the removal assessment conducted on July 25, 2006, documented that the mean and 95% upper confidence limit concentration for the sample population significantly exceeded health-based benchmarks (i.e., Region 9 Preliminary Remediation Goals (“PRG”)) and background concentrations for arsenic and lead.
Investigations by USFS and U.S. EPA provide evidence that continued releases from the site pose an imminent and substantial threat to human health, welfare, or the environment. An Action Memo, discussing the necessary steps to prevent the release of hazardous substances and AMD from mine tailings and waste rock to Joe Creek, Elliott Creek and their unnamed tributaries and to the surrounding environment where there is a greater likelihood of direct human contact, was written and approved. The removal action will include the following activities:
(1) Stabilize tailings and waste rock on steep slopes using slope stabilization techniques.
(2) Construct a sedimentation basin at the toe of the waste rock slope and above the log tailings dam. The basin will help de-energize run-off and allow metal-laden sediments to settle out.
(3) Strengthen the log tailings dam using large rocks from around the Site.
(4) Install passive AMD treatment.
Removal activities at the Blue Ledge Mine Site began on August 28, 2006. A summary of on-site activities between August 28, and September 1, 2006, is presented below.
August 28, 2006
Personnel: 2 EPA, 9 ERRS, 0 START
Weather: Clear skies, Sunny, High 80’s
Activities: On Monday, August 28, 2006, ERRS and the USEPA mobilized to the site. Equipment mobilized to the site included: a generator, a water truck, a bull dozer, a Gator, and an excavator. ERRS repaired Forest Service Road 1060. The road was re-graded with a bull dozer so that heavy equipment could be brought up to the staging area of the site. A drainage culvert was installed to repair a large, eroded section of the Road 1060. Additionally, ERRS began grading new roads on the Site itself. The roads will allow heavy equipment access to both high and low areas of the waste rock pile. The high road will provide heavy equipment access near the top of the waste rock pile where a drainage channel will be installed. The low road will allow heavy equipment near the bottom or toe of the waste rock pile where a sedimentation basin will be installed and the log tailings dam reinforced.
August 29, 2006
Personnel: 2 EPA, 9 ERRS, 0 START
Weather: Clear skies, Sunny, Mid 80’s
Activities: On Tuesday, August 29, 2006, ERRS continued grading and clearing the lower site road and began grading and clearing the upper site road using the bull dozer and the excavator. Pete Jones with the United States Forest Service was on site for a site walk and a discussion of the scope of the project.
August 30, 2006
Personnel: 1 EPA, 9 ERRS, 1 START
Weather: Clear skies, Sunny, High 80’s
On Wednesday August 30, 2006, START mobilized to the site to perform documentation and technical support. ERRS installed two culverts so that access roads could be temporarily built over on-site streams, finished grading and clearing the upper site road, and completed additional grading and clearing of the lower site road. Additionally ERRS began grading a terrace on the upper slope of the waste rock pile. The terrace was sloped into the pile to create a drainage trench which will direct runoff water away from the waste rock pile and reduce the volume of water flowing through the pile.
August 31, 2006
Personnel: 1 EPA, 9 ERRS, 1 START
Weather: Clear skies, Sunny, High 80’s
On Thursday August 31, 2006, completed installation of fence posts for a retaining wall which will be constructed on the west side of the upper terrace of the waste rock pile. The wall should prevent waste rock material from sliding in this area where it might potentially fill in the terrace area and reduce the effectiveness of the terrace for directing runoff. 14 posts were installed, at approximately 5 foot intervals. ERRS also began stockpiling large rocks from the waste rock pile to use in armoring the log dam at the base of the waste rock pile. Additional equipment mobilized to the site included a front end loader and a gas powered auger. The fire plan for the site was submitted to the Forest Service on this date.
September 1, 2006
Personnel: 1 EPA, 9 ERRS, 1 START
Weather: Clear skies, Sunny, High 80’s
On September 1, 2006, ERRS completed clearing out lower access road to provide adequate access for the front end loader, additional grading of the lower waste rock pile, installed boards on the upper retaining wall, and began clearing material from the channel below the log dam. During clearing of material below the log dam, it was noted that a significant amount of waste rock material including fine material was present in the channel. The OSC decided that this material would be removed from the channel and placed up above the log dam to prevent migration of the material downstream with runoff water.
Work will continue at the site half the day on September 2, and then return to full days on September 4, 2006. The ERRS contractor will continue to clear stream channel of waste rock material and transport it back above the log tailings dam. Additional removal actions that the ERRS contractor will start next week include: construction of a sedimentation basin, passive treatment efforts and re-enforcing log tailings dam.
See Above.
An action memorandum amendment requesting additional time and money has been submitted for approval. The ERRS contractor's task order ceiling will be amended as soon as the action memorandum amendment is approved.
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