Public Comment July 15 to August 15, 2011
Blackbird Mine Superfund Site
Lemhi County, Idaho
July 2011
EPA seeks your comments on revisions to the Blackbird Mine cleanup plan. EPA has explained these
changes in a draft Explanation of Significant Differences to the 2003 Record of Decision for the Blackbird
Mine Superfund Site. These revisions involve new sediment control measures, cobalt cleanup levels, and
arsenic cleanup levels.
Sediment Control Measures will
Reduce Recontamination along
Panther Creek
Numerous cleanup actions have attempted to
reduce contaminated sediments in Blackbird Creek
from polluting other areas outside the mine site. In
several cases after cleanups were completed, high
runoff caused recontamination of sediment and
areas along the banks of Panther Creek.
Different alternatives were considered to address
this problem. The most effective alternative is
believed to be one that installs a diversion from
Blackbird Creek and constructs two settling basins
at the former Panther Creek Inn property. EPA
anticipates that these additional measures will
reduce the potential for contaminated sediments
to be deposited along the banks of Panther Creek
during high flows. Also, EPA expects to decrease
disruption to private property and public land along
Panther Creek.
Changes to Cobalt Cleanup Levels
In 2008, EPA published new health toxicity values
for cobalt. Using these new values, EPA developed a
soil cleanup level, revised the groundwater cleanup
level, and re-calculated health risk for cobalt at this
site. The draft report explains these changes as well
as soil and groundwater test results from some areas
at the Blackbird Mine site that exceeded the revised
cleanup levels.
Changes to Arsenic Cleanup Levels
In 2003, EPA established an arsenic soil cleanup
level based on recreational day-use in the area.
Since then, EPA has discovered that recreational
uses vary depending on access to U.S. Forest Service
lands near Panther Creek. Based on this new
information, the draft report explains an increase of
the arsenic cleanup level from 590 mg/kg to 1180
mg/kg for some rarely used U.S. Forest Service
lands that require fording Panther Creek.
[Public CommentJSought
How to Comment
EPA is accepting written comments about the
changes to the cleanup plan until August 15,2011.
Send comments to: ^
Fran Allans
U. S. Environmental Protection Agency
1435 N. Orchard Street, Boise, ID 83706
allans.fran@epa.gov
Fax: (208)378-5744
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United States
Environmental Protection
Agency
1200 Sixth Avenue, Suite 900, ETPA-081
Seattle, Washington 98101-3140
July 2011
Revisions Planned for
Blackbird Mine Cleanup
Public Comment July 15 - August 15,2011
Site History
Blackbird Mine is an inactive mine located about
25 miles west of the town of Salmon in east central
Idaho in Lemhi County. Cobalt, silver and copper
ore were extracted from underground and open pit
mining operations. The main environmental concerns
at the site are cobalt, copper and arsenic released
into Blackbird Creek, the South Fork of the Big
Deer Creek, Big Deer Creek, and Panther Creek and
contamination along the banks of Panther Creek.
Contaminated soil, sediments and tailings were re-
leased from the Blackbird Mine site during multiple
high water flows from thunderstorms and snowmelt.
The Potentially Responsible Party group, referred to
as the Blackbird Mine Site Group, has conducted the
investigations and cleanup actions under EPA over-
sight and in consultation with the State of Idaho, U.S.
Forest Service, and the National Oceanic Atmospher-
ic Administration. The Blackbird Mine Site Group
consists of Noranda Exploration, Noranda Mining
Inc., M.A. Hanna Company, Roject Enterprises, Alu-
met, and Intalco Aluminum Corporation.
Next Steps
EPA will consider all public comments. EPA will
respond to comments and include the summarized
responses with the draft Explanation of Significant
Differences document.
For More Information
The draft Explanation of Significant Differences
describing the revisions is at: http://yosemite.epa.
gov/rlO/cleanup.nsf/sites/blackbird
The draft Explanation of Significant Differences
and supporting documents for the changes are in
the Administrative Record file for the site,
located at:
Salmon Public Library
204 Main Street, Salmon, Idaho
@ Please call for hours: (208) 756-2311
U.S. EPA Idaho Operations Office
1435 North Orchard Street, Boise, Idaho
@ Please call for hours: (208) 378-5746
U.S. EPA Region 10 Records Center
1200 6th Avenue, Seattle, Washington 98101
© Please call for an appointment (206) 553-4494
Questions? Contact:
Fran Allans, Project Manager
(208)378-5775
0 allans.fran@epa.gov or
Cyndi Grafe, Community Involvement Coordinator
@ (208)378-5771
^ grafe.cyndi@epa.gov
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