2008-09-25_REPORT - C1980007

• Permit No: C1980007
• IBM Index Class Name: REPORT
• Doc Date: 9/25/2008
• Doc Name: 3rd Qtr 2006 Thru 2nd Quarter 2008 Seismic Review Memo
• From: DRMS
• 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
4
1313 Sherman St., Room 215 g
Denver, Colorado 80203 C O L O R A D O

Phone: [phone] D I V I S I O N O F

RECLAMATION
FAX: [phone] MINING

MEMO SAFETY
4
From: Tom KaldenbachT Bill Ritter, Jr.
Governor

To: File Harris D. Sherman
Executive Director
West Elk Mine (C-1980-007)
Ronald W. Cattany
Report Division Director
Seismic Monitoring Reports (Q3-06 through Q2-8, 5 reports) Natural Resource Trustee
Date: September 25, 2008
MCC submitted the above-referenced reports in advance of longwall mining in the E
Seam. The reports indicate an adequate seismic monitoring program is in place for
identifying the magnitude of seismic events at Monument Dam. When MCC begins
longwall mining in the E seam, 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 II Mine enable determination of the geographic location and depth of
each seismic event. The above-referenced reports indicate the peak ground accelerations
at the dam during the Q306 to Q208 period did not exceed the 0.15 g threshold.
cc: Dan Hernandez, DRMS
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines