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Subsidence Field Observations <br />West Elk Mine <br />' August 28 and 29, 2001 <br />3.2 Subsidence Evaluation of August 29, 2001 <br />The traverses (by ATV and one on foot) were along roads and trails above mined-out longwall <br />' panels 12, 13, and 13-A and in the Minnesota Reservoir area. The subsidence cracks in the <br />Apache Rocks area were also reevaluated. <br />3.2.1 Traverse E-E' <br />' Traverse E-E' is along the drill road from drill hole SOM-49 to drill hole SOM-C-75. <br />• The traverse is above the eastern part of mined longwall panels 13 and 13-A in <br />overburden ranging from 950 to 1,250 feet thick. <br />' • No subsidence features were observed along the drill road. <br />• Two ponds, one located on the east and one located on the west side of the road, appear <br />to contain the amount of water consistent with the time of the year and current weather <br />t conditions. <br />3.2.2 Location 6 <br />' Location 6 is at the cracks in the Mesaverde sandstones at Apache Rocks (Location 7 of 2000). <br />• It is located above the double rigid pillars at the southeast edge of longwall panel 12 in <br />overburden 1,350 feet thick. <br />• The cracks are located within the tension zone produced by the extraction of longwall <br />panels 12 and 13. <br />' • As reported in 2000, the cracks are straight to branching and converging, as much as 3% <br />inches wide and generally trend northeastward, eastward and northwestward. <br />' • Some cracks appear to be 10 to 20 percent wider and longer that they were at the last <br />visit on August 28, 2000. <br />1 <br />831-032.560 Wright Water Engineers, Inc. Page 7 <br />' September 2001 <br />