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Review Checklist for Subsidence Monitoring Report <br />Mine: West Elk Mine Date this review was completed: 6/9/09 <br />Permit No.: C-80-007 CDRMS reviewer: Tom Kaldenbach <br />Report period: Fall 2008 <br /> In <br />Monitoring requirement Regulation citation compliance: Comment <br /> Yes / no ? <br />Installed and surveyed Prior to 2000, West Elk monitored <br />monuments prior to 2.05.6(6)(c)(i)(A) Yes subsidence in a monument grid installed <br />undermining. over their first three longwall panels. This <br />Located monuments to monitoring verified their subsidence <br />detect vertical subsidence 2.05.6(6)I(i)(B) Yes predictions. From 2000 through Spring <br />and horizontal 2007, West Elk conducted an annual visual <br />displacement. inspection of recently undermined areas <br />Monitored each structure's and previously identified subsidence <br />orientation, location, 2.05.6(6)I(i)I Yes features. The frequency of this visual <br />elevation. inspection was increased to semi-annually <br />Monitored each monument beginning in Fall 2007. The only structure <br />and structure at least 2.05.6(6)I(i)(D) Yes that was undermined since the previous <br />quarterly. report (Spring 2008) was the mine <br />Commenced monitoring of operator's access road in Box Canyon, <br />each monument and which was monitored visually. Panel 25 <br />structure at least one 2.05.6(6)I(i)(D) Yes has undermined Sylvester Gulch since the <br />month prior to Spring 2008 report. The monitoring plan <br />undermining. requires pre-mining and post-mining <br /> subsidence monitoring of Sylvester Gulch. <br />Submitted monitoring The monitoring plan is consistent with the <br />report at least 2.05.6(6)I(i)(E) Yes existing level of need for verifying the <br />semiannually. subsidence prediction, as required by <br /> 2.05.6(c)(i)(F). <br /> <br />Conducted sufficient post- <br />mining monitoring to <br />verify subsidence <br />prediction <br /> <br />2.05.6(6I(i))(F) <br /> <br />Yes The traverses in the Fall 2008 study <br />included observations of new and <br />previously identified subsidence features. <br />The report describes changes to the <br />previously existing features that have <br />occurred since previous visual inspections._ <br /> The Fall 2008 report describes new <br /> subsidence cracks in the mine operator's <br /> Box Canyon access road (recently <br />Accurately predicted undermined by Panel 18) and new <br />subsidence 2.05.6(6)(d)(i) Yes rockfalls on the east side of Sylvester <br />. Gulch (recently undermined by Panel 25). <br /> These impacts are consistent with the <br /> subsidence prediction in the permit <br /> application. <br />There was no imminent or <br />actual material damage or <br />diminution of use of 2.05.6(6)(d)(i) Yes <br />renewable resource lands <br />or structures