2012-05-30_REPORT - C1980007 ‎(8)‎

• Permit No: C1980007
• IBM Index Class Name: Report
• Doc Date: 5/30/2012
• Doc Name: 2011 Subsidence Monitoring Report
• From: Wright Water Engineers, Inc
• To: DRMS
• Permit Index Doc Type: Subsidence Report
• Email Name: JRS
• Email Name: DIH
• Media Type: D
• Archive: No

FALL 2011 SUBSIDENCE AND GEOLOGIC FIELD OBSERVATIONS
Box Canyon, Apache Rocks, and South of Divide Mining Areas
1.0 INTRODUCTION
Beginning in 2007, Wright Water Engineers, Inc. (WWE) has been conducting semi- annual
(spring and fall) field visits to the area over the West Elk Mine as operated by Mountain Coal
Company, LLC (MCC) making subsidence and geologic observations. Prior to 2007, WWE
performed annual field visits dating back to 1996. Each of these visits provides observations
related to subsidence effects resulting from the longwall mining of coal in the B- and /or E -seam.
These observations have been subsequently chronicled in an annual or semi - annual subsidence
report ' .
This semi - annual subsidence report (Fall 2011 Report) is the second of two reports to be
generated based on observations made during the 2011 calendar year. In accordance with MCC"s
Colorado Division of Reclamation, Mining and Safety (CDRMS) permit, subsidence reports are
to be submitted by April 30 (for preceding fall monitoring) and September 30 (for preceding
spring monitoring).
Field observations represent at least 80 percent of the text contained within each of the
subsidence reports. The remaining 20 percent is repeated reference text for the convenience of
the reader. As of the Fall 2010 Report, WWE and MCC will substantially reduce the size of the
annual fall subsidence report. Reference will be made to the spring subsidence report for those
details that have been characteristically found in previous reports (e.g., field recognition of
subsidence and non - subsidence features, conclusions, and a bibliography). This is true of
Appendix A of the Spring 2011 Report, which provides a summary of the subsidence prediction
information contained in Exhibit 60 through 60E of the current permit issued by the CDRMS.
1 Annual and semi - annual subsidence and geologic field observation reports, as well as exhibits to the West Elk Mine
permit document (Exhibits 60, 60A, 60B, 60C, 60D. and 60E), are kept at Mountain Coal Company, LLC and at
the Colorado Division of Reclamation, Mining, and Safety.
831 - 032.793
May 2012
Wright Water Engineers, Inc. Page 1