2010-07-22_REPORT - C1980007 ‎(3)‎

• Permit No: C1980007
• IBM Index Class Name: REPORT
• Doc Date: 7/22/2010
• Doc Name: 4th Qtr 2009 Review Memo
• From: T 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 4th Quarter 2009
Date: July 22, 2010
Re: Summary of DRMS Review
COLORADO
D I V I S 10 N O F
RECLAMATION
MINING
SAFETY
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). MCC began longwall mining in the E seam in the
4th quarter of 2008. MCC is 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 II
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 4th quarter of 2009 did not exceed the 0.15 g threshold.
cc: Kathy Welt, DRMS
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines