2010-03-04_REVISION - C1996083 ‎(3)‎

• Permit No: C1996083
• IBM Index Class Name: REVISION
• Doc Date: 3/4/2010
• Doc Name: Geotechnical Adequacy Review ‎(Memo)‎
• From: Marcia Talvitie
• To: Joe Dudash
• Type & Sequence: TR65
• Email Name: JJD
• Email Name: SB1
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
COL O R A D O
Denver, Colorado 80203 DIVISION O F
Phone: [phone] RECLAMATION
FAX: [phone] MINING

SAFETY
INTEROFFICE MEMORANDUM
Bill Ritter, Jr.
Governor
Date: 04 March 2010 Harris D. Sherman
Executive Director
To: Joseph J. Dudash, Lead Specialist Ronald W. Cattany
Division Director
Natural Resource Trustee
From: Marcia L Talvitie, P.E. -11W
Subject: Bowie No. 2 Mine - Permit No. C-1991-083
TR-65 - Amend B-Seam Mine Plan and Add Geotech Hole
Geotechnical Adequacy
I have reviewed BRL's response to the adequacy issues listed in my preliminary review
letter to you dated the 8th of January. The original TR-65 application included a March
2004 study prepared by Maleki Technologies, Inc. ("MTI 2004") entitled "Overburden
Stability Evaluation at Terror Creek Crossing". The adequacy response package included
an updated report from Maleki, bearing the, same title, dated January 2010 ("MTI 2010").
My comments updating each of my original adequacy items are presented in bold type
below. Items have been numbered to match the system used in your Preliminary
Adequacy Review letter.
MTI 2004 Section 2.0 - Data Collection Program
14. Three geotechnical holes were drilled, and are illustrated on Figure 1. The
locations of these three holes with respect to one another differ from what is
shown on Map 09. Please verify that locations shown on Map 09 for
geotechnical holes TC-03-01, TC-03-02 and TC-03-03 are accurate, and revise if
necessary.
Locations shown on Map 09 were correct; MTI 2010 Figure Ia was revised
accordingly. Item resolved; no additional response is required.
15. Page 6 of MTI 2004 states that holes TC-03-02 and TC-03-03 "were drilled
directly above the projected location of the mains." TDR cables were cemented
in all three holes (see Page 8), providing a means of "identifying the location of
bed separation and shearing along the entire overburden." With the new proposed
location of the West Mains, the TDR cables installed previously would not seem
to be able to provide BRL with the same level of information. However, revised
pages 2.05-120 and -125 describe and list four subsidence monuments proposed
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines