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Mountain Coal Company <br />West Elk Mine <br />1996 Annual Subsidence Report <br />Year-end Report <br />The most current subsidence survey for the Rrest Elk Ivtine was performed in October of <br />1996, by Valley Survey Inc. The survey was conducted using radial and level loop survey <br />methods. The instrument used was a HP3820A Total Station. <br />The following tables reflect the northings, eastings, average pre-mining elevations, the <br />previous report elevations (July 1996), the current survey elevations, subsidence since the <br />July 1996 report, and total subsidence. <br />The tables indicate that the maximum total subsidence to date is 8,25 feet and occurs over <br />both the F and B Seams at point No. 41, which is over the center of the 1st Northwest <br />Longwall Panel. The subsidence measured is well within the range of the predicted <br />subsidence, (Exhibit 60). In this azea of two-seam mining, complete maximum subsidence <br />can be calculated by simple addition of the maximum predicted subsidence for both the F <br />and B Seams. The total predicted subsidence for the 2-seam mining is 10.22 feet. <br />The visual effects of subsidence for this survey period were limited to scazs that have <br />healed across the panels. These healing cracks appeaz over the fifth, sixth, and seventh <br />Northwest Longwall panels in the B-seam. Displacement at or neaz the cracks was not <br />perceptible. <br />Mining advance was limited to the B-seam development in the 8th Tailgate, 8th Headgate <br />and the 9th Headgate sections and the mine headed east with entries in the B East Mains. <br />The longwall retreated in the 7th Northwest Longwall Panel (NWLW) and the 8th <br />Longwall Panel since July 1996. The longwall is currently (May 1997) mining the 9th <br />Panel. <br /> <br />