2008-06-13_REVISION - C1981010

• Permit No: C1981010
• IBM Index Class Name: REVISION
• Doc Date: 6/13/2008
• Doc Name: Response to Proposal
• From: DRMS
• To: Knight Piesold and Co
• Type & Sequence: PR6
• Email Name: JDM
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
June 13, 2008
Allison White, EIT
Knight Piesold and Co
1580 Lincoln Street, Suite 1000
Denver, CO 80203-1512
RE: Permit Revision PR-06, Trapper Mining Inc, The Trapper Mine
CDRMS Permit No. C-1981-010
Dear Ms. White:
COLORADO
D I V LS I O N O F
RECLAMATION
MINING
SAFETY
Bill Ritterjr.
Governor
Harris D. Sherman
Executive Director
Ronald W.'Cattany
Division Director
Natural Resource Trustee
We have reviewed the May 15, 2008 proposal submitted by Knight Piesold pertaining to Permit
Revision PR-06 for the Trapper Mine. We have reviewed the discussions provided in this
proposal relative to the interpretations of the terms "approximate original contour" and "excess
spoil", and have reviewed the proposed post-mining topographies for the proposed K Pit and the
proposed Horse Gulch Fill that reflect these discussions and interpretations. We wish to now
provide our comments in response.
With regard to the discussions relative to the concept of "approximate original contour", we
believe an interpretation broader than the one currently proposed is needed. We believe that the
"approximate original contour" concept should be applied to all areas proposed to be disturbed by
Trapper Mining Inc, rather than solely to the K Pit area. This would include the proposed Horse
Gulch Fill area.
We believe that the proposed reduction in elevation of approximately 100 feet from pre-mining to
post-mining topography in the K Pit excavation area, and the proposed resultant Horse Gulch Fill,
spoil pile that at its peak would be approximately 300 feet higher than its pre-mining elevation, do
not comply as well with the concepts of "approximate original contour" and "excess spoil" as
proposals that would return the K Pit excavation area to as close to its pre-mining topography as
possible (without creating the potential for further geotechnical instability) and create a smaller
Horse Gulch Fill spoil pile with the remaining spoil.
With regard to the concept of recreating post-mining surface drainage patterns that mimic the pre-
mining surface drainage patterns, we believe the currently-proposed size of the Horse Gulch Fill
relative to the size of the Horse Gulch drainage is a significant deviation from the pre-mining
hydrologic pattern. A smaller Horse Gulch Fill, created as a result of reclaiming the K Pit
excavation area to as close to its pre-mining topography as possible, would reduce this degree of
change to the Horse Gulch pre-mining drainage pattern.
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines