2008-12-22_REPORT - C1980007 ‎(2)‎

• Permit No: C1980007
• IBM Index Class Name: REPORT
• Doc Date: 12/22/2008
• Doc Name: 3rd Qtr 2008 Seismic Review Memo
• From: Tom Kaldenbach
• To: File
• Permit Index Doc Type: Stability Report
• Email Name: TAK
• 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]
MEMO
From: Tom Kaldenbach
To: File
West Elk Mine (C-1980-007)
Report
Seismic Monitoring Report for 3rd Quarter 2008
Date: December 22, 2008
Re: Summary of DRMS Review
COLORADO
D I V I S ION O F
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
Harris D. Sherman
Executive Director
Ronald W. Cattany
Division Director
Natural Resource Trustee
MCC's Subsidence Monitoring Plan requires monitoring of seismicity for identifying the
magnitude of seismic events at Monument Dam (Sections 2.05.6(6(b)(ii), (6)(c(ii), and
(6)(e)(iii) of the permit application). When MCC begins longwall mining in the E seam
in 4t" quarter 2008, they will be required to make field measurements of monuments on
the dam within two days of any mining-caused seismic event that exceeds peak ground
acceleration of 0.15 g at the dam (permit application page 2.05-168). An accelerometer
at the dam continuously monitors seismic activity. Data from the Monument Dam
accelerometer and nine other accelerometers installed at the West Elk Mine and Bowie :[I
Mine enable determination of the geographic location and depth of each seismic event.
The above-referenced reports indicates the peak ground accelerations at the dam during
the the 3rd quarter of 2008 did not exceed the 0.15 g threshold.
cc: Dan Hernandez, DRMS
Henry Barbe, DRMS
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines