2013-10-22_REPORT - C1981010

• Permit No: C1981010
• IBM Index Class Name: Report
• Doc Date: 10/22/2013
• Doc Name: Review of Geotechnical Monitoring Report ‎(Memo)‎
• From: Marcia Talvitie
• To: Jared Ebert
• Permit Index Doc Type: Stability Report
• Email Name: JLE
• Email Name: SB1
• Email Name: MLT
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
O L O R A D O
Denver, Colorado 80203
nivts�ar� OF
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Phone: [phone]
RECLAMATION
FAX: [phone]
MINING
SAFETY
INTERNAL MEMORANDUM
Jahn W. Hickenlooper
Governor
Date: 22 October 2013
Mike King
Executive Director
Loretta E. Piheda
To: Jared L. Ebert, Lead Specialist
Director
From: Marcia L. Talvitie, P.E. 4 elt
Subject: Trapper Mine (C -1981-010)
Review of September 2013 Semi - Annual Geotechnical Monitoring Report
At your request, I have reviewed the Semi - Annual Geotechnical Monitoring Report (GMR) from
Trapper Mining, Inc., dated September 25, 2013. This report covers the period of time between
March 26, 2013 (the cover letter mistakenly says 2012) and September 24, 2013.
Just two monitoring stations remain in service: Stations 7 and 8. The March 2013 GMR
explained that due to technical issues and physical damage, inclinometer and piezometer data can
no longer be collected at Station 7. The cover letter for the September 2013 GMR states that,
"Inclinometer, piezometer and surface displacement graphs for both sites... are attached." This
statement is in error, as only surface displacement data is provided for Station 7.
GPS data from Station 7 does not show that any significant movement has occurred during the
last six months.
As noted in Trapper's GMR cover letter, Station 8 continues to report a small amount of
movement along the southern edge of the pit. The letter explains that a buttress was built below
Station 8, to the level of the L seam, at the recommendation of their consultant. I compared the
GPS data from this report with that included in the March 2013 GMR. It does appear that the
buttress has had a stabilizing effect; the rate of displacement has been significantly reduced from
what was observed in late winter of 2013. It would be helpful to know when the buttress was put
in place.
Please feel free to contact me with any additional questions you may have.
cc: Sandy Brown, DRMS
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines