2009-06-01_REVISION - C1996083

• Permit No: C1996083
• IBM Index Class Name: REVISION
• Doc Date: 6/1/2009
• Doc Name: Adequacy Review
• From: DRMS
• To: Bowie Resources, LLC
• Type & Sequence: TR61
• 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]
June 1, 2009
Mr. William A. Bear
Bowie Resources LLC
P.O. Box 483
COLORADO
D I V I S I ON O F
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
Harris D. Sherman
Executive Director
Paonia, Colorado 81428 Ronald W. Cattany
Division Director
Natural Resource Trustee
RE: Bowie No. 2 Mine, Permit No. C-96-083, Bowie Resources LLC
Technical Revision No. 61, Coal Refuse Pile Slope Inclination, Adequacy Review
Dear Mr. Bear:
The Colorado Division of Reclamation, Mining and Safety (Division) has finished its adequacy
review of Technical Revision No. 61 (TR-61), submitted by Bowie Resources LLC for the Bowie
No. 2 Mine. The following are the Division's TR-61 adequacy review questions, divided into three
major sections; the Geotechnical Review, the Hydrologic Review and the Reclamation Cost Estimate
Review.
Geotechnical Review
The application for TR-61 was prepared to update the permit application package to reflect a
steepened slope configuration for Coal Mine Waste Disposal Area #2 (CMWDA2) that was
previously approved under TR-56. With TR-56, the operator successfully demonstrated [in a
report prepared by Buckhorn Geotech, Inc. (BGI)] that slopes as steep as 3H:1 V for the upper
portions of CMWDA2 will provide a Factor of Safety of 1.50 when proper methods of
construction are used and site conditions are periodically monitored.
In its review for TR-56, the Division listed several items that the upcoming technical revision
application (TR-61) would be expected to address. Those items are each repeated below ("OC",
for "Original Comment"), followed by an evaluation of the current TR-61 application ("NC", for
"New Comment").
Vibrating Wire Piezometers
OC: Five instruments were originally installed in four separate holes in 2005; two of the
piezometers (in two holes) later ceased to function. Pore pressure data from the remaining
three piezometers were utilized to develop assumptions for use in the stability evaluation. In
Section 6.0 (Page 14 of 15), BGI recommends on-going monitoring of piezometers as
construction of CMWDA2 progresses.
Please describe the proposed on-going piezometr c monitoring plan, including the locations
of any new piezometers to be placed, any anticipated modification of existing piezometers,
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