2009-02-04_REPORT - C1981010

• Permit No: C1981010
• IBM Index Class Name: Report
• Doc Date: 2/4/2009
• Doc Name: Semi Annual Geotechnical Monitoring Report Review
• From: DRMS
• To: Trapper Mining, Inc
• Permit Index Doc Type: Stability Report
• Email Name: JDM
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203 COLORADO

Phone: [phone] D I V I S ION OF
RECLAMATION
FAX: [phone] MINING
- St-
SAFETY
February 4, 2009
Bill Ritter, Jr.
James Mattem Governor
Trapper Mining, Inc Harris D. Sherman
Executive Director
P.O. Box 187

Craig, CO 81626 Ronald W. Cattany
Division Director
Natural Resource Trustee
RE: Trapper Mining, Inc., Permit C-81-010
Semi-annual Geotechnical Monitoring Report (Sep-2008)
Dear Mr. Mattern,
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 30 Sep 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.
The September 2008 GMR expands upon the data presented in the March 2008 GMR, and includes
inclinometer, piezometer and benchmark data collected from April through September 2008. Based
upon the results to date, TMI's geotechnical consultant, Agapito & Associates, Inc. (AAI) recommends
reducing the data collection frequency. The following table provides a comparison between the
Approved and Recommended monitoring frequencies for the G-Pit Slide Area.
Approved Monitoring

Frequency New Frequency Recommended by AAI
Inclinometers /Piezometers / Inclinometer l

Benchmarks
Benchmarks Piezometers
Once per month during dry
Once per month during dry season (No Change)
season
Once per week April-May

and September-October Once per week for two Once per week for two

Once per day after rainstorm seeks following a major weeks following a major

events >0.50 inches for 3-4 rainstorm event (>0.5 inch) rainstorm event (>0.5 inch)

days transitioning to weekly or major snow melt (loss of or major snow melt (loss of

for 1-2 weeks cover >2 inches) cover >2 inches)
For reference, a tabulated frequency of data collected at each site, based on the calendar month was
derived. The resulting spreadsheet is enclosed with this memorandum. It appears that two
inclinometers are still viable, along with three piezometers. Twenty benchmarks, of varying types,
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