2008-12-16_REVISION - C1981022

• Permit No: C1981022
• IBM Index Class Name: REVISION
• Doc Date: 12/16/2008
• Doc Name: 2nd Adequacy Review
• From: Joe Dudash
• To: Marcia Talvitie
• Type & Sequence: TR60
• Email Name: JJD
• Media Type: D
• Archive: No

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]
DATE: December 16, 2008
COLORADO
D I V I S I O N OF
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
TO: Marcia Talvitie
Harris D. Sherman
Executive Director
FROM: Joe Dudash Ronald W. Cattany
0 Division Director
RE: Elk Creek Mi"`nne, Permit No. C-1981-022, Oxbow Mining LLC Natural Resource Trustee
Technical Revision No. 60, Bear Creek Fan Site, Second Adequacy Review
I have finished my review of Oxbow's responses, dated November 26, 2008, to the Division's
preliminary adequacy review letter, dated November 10, 2008, for Technical Revision No. 60 for
the Elk Creek Mine. The following is the resolution status of my original comments and
questions. The numbering is consistent with the numbering of the Division's preliminary
adequacy review letter. Question number 21 is a new question, however.
Please describe the fan shaft construction measures that Oxbow will employ to prevent or
minimize ground water flow seeping into the fan shaft.
The Division has no further concerns. Oxbow described the pre-drilling and grouting
procedure that will be used if ground water is encountered.
2. Rule 2.05.6(3) requires that ground water quantity be protected from proposed mining
operations. Please propose a hydrologic monitoring program to determine the
occurrence and quantity of water that seeps into the fan shaft from the Bear Creek
alluvium.
Oxbow responded in their November 26, 2008 submittal that the current plan of
monitoring water seepage into the mine and reporting this seepage in the annual
hydrologic report is sufficient. However, the Division does not believe that annual
monitoring and reporting can provide enough of an early warning of any problems that
might be occurring due to the shaft being so close to Bear Creek. The Division requests
that the presence and quantity of groundwater inflow into the shaft be measured and
reported to the Division on a monthly basis during, if possible, and after construction of
the shaft.
3. The text at the beginning of Section 9 of the TR-60 submittal states that the entire Bear
Creek fan site is a small area exemption (SAE). However, the hydrology designs
presented in TR-60 designate only three portions of the disturbed area as SAES. Other
disturbed areas, such as the cut slopes and pad area, are not designated as an SAE on
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