REV105462

• Permit No: C1981038
• IBM Index Class Name: Revision
• Doc Date: 12/17/2004
• Doc Name: Response to Request Assistance for Review ‎(Interoffice Memorandum)‎
• From: Byron Walker
• To: Joe Dudash
• Type & Sequence: TR45
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OE MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
OLORADO
I VI SION OF
INE~RALS
EOLOGY
_LAMATION•MINING
SAFETY•SC IENCE
Interoffice MEMORANDUM BIII Owens
Governor
to: Joe Dudash Russell George
from• Byron G. Walker(!/ Executive Director
cc: Dan Hernandez, Sand Brown Ronald W. Cottony
y Division Director
subject: Review of TR-45, Reduce Subsidence Monitoring Bowie No. 1 Mine, Perltdtital`~6pvrce Trustee
C'- 8I -03 `~ 3: Bowie Resources LTD
date: December 17, 2004
This memorandum is in response to your request for assistance dated December 13, 2004.
I have reviewed the application, my memo of December 1 1, 2001, the BLM letter of January 7,
2002 (TR-40), and portions of the Permit Application Package (PAP) regarding suspension of
subsidence monitoring.
The applicant makes reference to page 147 of the PAP that states "Wide-spaced monument
surveying shall continue on an annual basis until sites are shown to be stabilized and approval to
discontinue monitoring selected sites is obtained from the Division." Annual monitoring is
required until the Division deems subsidence to be complete (PAP page 147; also memo,
Pendleton to Shuey, February 6, 1992, TR-16). In addition, the monitoring plan is described in
the PAP, beginning on page 144. Monitoring is to continue until the operator, in concurrence
with the Division, decides subsidence monitoring is no longer required [PAP, Section
2.05.6(6)(i)(C), page 144]. The application includes good documentation that the sites have
stabilized and the subsidence is likely complete.
However, Rule 2.05.6(6)(c)(i)(F) requires that the monitoring program shall be designed to
extend for a time, beyond cessation of mining in any area, consistent with the need for
verification of the subsidence prediction. This requirement does not appeaz in the PAP, and the
application is silent on this requirement. The rest of this memo addresses this requirement.
"No hydrologic impact" is predicted on page 129 of the Permit Application Package (PAP).
There should be no adverse impact to Steven's Gulch or East Roatcap Creek (PAP page 133).
The worst possible consequences to structures are described on page 140 of the PAP. The Pitkin
Mesa - Orchazd Valley Line may become disrupted or separated (PAP page 140). The mining
plan was designed to prevent material damage to renewable resources in Steven's Gulch, East
Roatcap Creek, and other areas (areas that support willows, reed grass, and other riparian
vegetation)(PAP Pages 141, 143). A theoretical model indicated magnitudes of subsidence up to
7 feet. Actual validation measurements indicated 4 feet maximum.
Office of Office of Colorado
Mined Land Reclamation Ac[ive and Inactive Mines Geological Survey