2008-11-07_REVISION - C1996083 ‎(3)‎

• Permit No: C1996083
• IBM Index Class Name: REVISION
• Doc Date: 11/7/2008
• Doc Name: Requirments for Implementation ‎(Memo)‎
• From: Marcia Talvitie
• To: Joe Dudash
• Type & Sequence: TR56
• 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]
COLORADO
D I V I S I O N O F
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
INTEROFFICE MEMORANDUM Governor
Harris D. Sherman
Executive Director
Ronald W. Cattany
Date: 07 November 2008 Division Director
Natural Resource Trustee
To: Joe Dudash
From: Marcia L. Talvitie, P.E.
Subject: Bowie No. 2 Mine (Permit No. C-1996-083)
TR-56 and TR-- (Pending)
Coal Mine Waste Disposal Area No. 2
Stability Evaluation - Requirements for Implementation
With its application for TR-56, Bowie Resources, LLC (BRL) requested a change in the
allowable side slopes for the Coal Mine Waste Disposal Area No. 2 (CMWDA2). In its
"Revised Stability Evaluations for Coal Mine Waste Disposal Area No. 2" report,
Buckhorn Geotech, Inc. (BGI) successfully demonstrated that slopes as steep as 3H:1 V
for the upper portions of CMWDA2 will provide a Factor of Safety of 1.50 (both during;
and after construction) when proper methods of construction are used and site conditions
are periodically monitored.
TR-56 is currently being approved, and the BGI report will be incorporated into the
Bowie No. 2 Mine PAP. It is my understanding that following the Division's approval of
TR-56, BRL will submit a new Technical Revision that will address implementation of
the conclusions and recommendations of the report.
The upcoming TR application will be expected to address several items, as described in
the following paragraphs.
Vibrating Wire Piezometers - 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.
Office of Office of
Mined Land Reclamation Denver - Grand )unction - Durango Active and Inactive Mines