2008-07-29_REPORT - C1981010

• Permit No: C1981010
• IBM Index Class Name: REPORT
• Doc Date: 7/29/2008
• Doc Name: Semi-Annual Geotechnical Monitoring Report Review
• From: DRMS
• To: Trapper Mining Inc
• Permit Index Doc Type: Reveg Monitoring Report
• Email Name: JDM
• 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]
July 29, 2008
James Mattern
Trapper Mining, Inc
P.O. Box 187
Craig, CO 81626
RE: Trapper Mining, Inc., Permit C-81-010
Semi-annual Geotechnical Monitoring Report
Dear Mr. Mattern,
COLORADO
D I V I S I ON OF
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
Harris D. Sherman
Executive Director
Ronald W. Cattany
Division Director
Natural Resource Trustee
The Colorado Division of Reclamation, Mining, and Safety (CDRMS) has reviewed the above-
described Geotechnical Monitoring Report ("GMR") for the Trapper Mine, received by the Division
on 27 Mar 2008. The Report is to be submitted semi-annually, per the requirements of Technical
Revision No. 99 (TR-99) to Permit No. C-1980-010, incorporated into Section 3.3.3 of the application
as pages 3-27a, 3-27b, 3-27c and 3-27d.
1) Table 3.3-3 includes proposed lengths (in feet) for the three inclinometers and four piezometers
installed. These lengths differ from those reported in the GMR (some are longer; some are shorter).
Please provide an explanation of the variations in length of instrumentation between Table 3.3-3
and the GMR.
2) Piezometer Data - The GMR cover letter (page 2) states that, "Piezometers inside the slide area
tend to have higher psi readings than those outside the slide area." The data presented for 07-GI3
(inside the slide) are, indeed, higher than the measurements reported for 07-GX5 (outside the slide),
but the pore pressure readings for 07-GI 10 (also inside) are more similar to 07-GX5 than they are to
07-GI3.
Please reconsider the statement referenced above, and rephrase, if necessary.
3) Piezometer Data - Page 2 of the GMR cover letter states, "Readings from the Z pit piezometer
indicate insignificant amounts of pore pressure. This piezometer was inadvertently destroyed in
September and is currently inactive." The Piezometer Data spreadsheet reports zero value for pore
pressures in the Z pit piezometer (07-ZI2) prior to the date at which it was destroyed.
Please provide the data (f any) that were collected for 07-ZI2 prior to the time the piezometer was
destroyed.
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines