2012-04-02_REPORT - C1996083 (5)

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Introduction This report is for the period from July 1, 2011 through December 31, 2011. Mine Construction of the Bowie No. 2 Mine began during May of 1997, with coal production beginning during August 1997. The mining permit application for the Bowie No. 2 Mine requires the operator to submit the results of the subsidence monitoring programs and the results of the visual inspections of known modern and historic landslides within the permit and adjacent area for stability in June and December of each year and report these results to the Division within 30 days of the end of the reporting period. The Operator is also required to inspect these landslides, both modern and historic, monthly for six months immediately after retreat mining occurs. This same inspection routine is applied to any spring or pond in the immediate proximity of retreat mining. During the reporting period, mining continued in the 2 West Mains. The B -10 longwall was completed with an advance of approximately 2,580 feet. Headgate and tailgate entries were completed for panel B -11. The B -11 longwall advanced approximately 1,200 feet. The B -12 headgate was advanced about 3,500 feet. The B -13 headgate was necked off. Visual Inspection of known historic and modern landslides. A visual inspection of all known historic and modern landslides was conducted during November 2011 by Brad Lindsay, Rock Logic Consulting LLC. Mr. Lindsay's report is attached. Twenty -one new subsidence cracks were noted. Bowie personnel routinely travel over the active workings as weather permits so any reactivated or new landslide would be promptly discovered. Increased Inspection activity associated with retreat mining. Accessible subsidence cracks are repaired during coal exploration events and are monitored by both coal exploration supervisors and hydrologic monitoring technicians. During this period Spring 21 was again potentially impacted or re- impacted. Spring 21 was monitoring twice during reporting period. Potentially impacted or re- impacted means the mine workings or angle of draw of the mine workings passed under the monitoring point during the reporting period. No influence to any hydrologic monitoring points was observed during this period. Results of Subsidence Survey Monitoring The results of the August and November 2011 monitoring are attached. As in the past, the survey was performed by Cragg Surveying using GPS methods. Analysis of Subsidence Data The following table presents an analysis of the subsidence survey data. Subsidence survey requirements are shown on PAP pages 2.05 -163 and 164. Following is a summary of the survey data collected during the period. -2-