2011-12-14_REVISION - M2005050

• Permit No: M2005050
• IBM Index Class Name: REVISION
• Doc Date: 12/14/2011
• Doc Name: Stormwater Management Review TR-02
• From: DRMS
• To: Rimrock Exploration
• Type & Sequence: TR2
• Email Name: GRM
• Media Type: D
• Archive: No

DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
Mined Land Reclamation
December 14, 2011
Rimrock Exploration
Wesley and Allen Chiles
P.O. Box 430
Nucla, Colorado 81424
Ge,
STATE OF COLORADO
Loretta E. Pifieda
Director
Re: J -Bird Mine, Permit No. M- 2005 -050, Stormwater Management Review, Technical Revision
TR -02.
Dear Mr. Chiles,
The Division of Reclamation, Mining, and Safety received Rimrock's Technical Revision request,
TR -02 for the J -Bird Mine to revise inconsistencies in the general mine plan versus on the ground
conditions and addresses final location of additional monitor wells required up gradient of
proposed underground operations. There was some confusion in regard to submission of
stormwater structure designs. Some of the files that were e- mailed apparently did not make it
to the Division because of their size and the request for a hard copy was missed. Staff
apologizes for its part in the matter.
Please find attached a review from staff regarding the proposed stormwater structure design.
The DRMS engineer notes an error within the computer modeling program used for flow designs
which carried over into Rimrock's proposals. The engineer notes the errors and methodology to
correct these. Also at issue is the durability of sandstone for rip- raping in channels and spill -a-
ways. Discussions with your consultant note that there is documentation to substantiate the
use of particular sandstone available on site rather than importation of harder materials. The
Division understands the wide variations in the material. Therefore it is a matter of identifying
the correct sandstone type for the purpose and documenting its hardness for durability analysis.
Due to the delay mentioned above the Division did not get its review back to your consultant
until December 7 2011. While they are currently working on a response the decision date of
December 15, 2011 cannot be met. Staff notes the issues are close to being resolved. However,
the holiday season begins next week so pushing the date past January 9 sometime should
allow for a response to the division's issues and a final review by us. Rimrock needs to submit a
decision date extension request by close of business on the 15
COLORADO
DIVISION OF
RECLAMATION
MINING
— &—
SAFETY
John W. Hickenooper
Governor
Mike King
Executive Director
Office of Office of
Denver • Grand Junction • Durango Active and Inactive Mines