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Fall 2009 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />5.13.4 Location 16 <br />As noted above, Location 16 is the upper Dry Fork flume. Physical observations obtained during <br />the fall 2009 field visit found this 30-inch flume to have a stage height of 0.21 feet, to be level in <br />an upstream/downstream orientation, and to have a right bank that is 1/16-inch lower than the left <br />bank. This flume is located above the middle of Longwall Panel E4 with approximately 1,100 <br />feet of E-seam overburden thickness. <br />5.14 Traverse K1-K1' <br />This traverse originates along the Dry Fork road and travels southeastward parallel to the Dry <br />Fork for approximately 1 mile across planned Longwall Panels E3 and E4 (Map 2) where the <br />overburden depth to the E-seam ranges from 700 to 1,050 feet. Observation made during the fall <br />2009 trip represent pre-mining baseline conditions with no evidence of slumping or cracking <br />along the roadway. <br />Thick soil and colluvium derived primarily from the Wasatch Formation were observed along <br />this traverse. <br />5.14.1 Photographic Observation Point 13 <br />This new photographic comparison location was established along Traverse K1-K1' <br />approximately 1,500 feet from K'. This location establishes two views; one looking northward <br />toward the MDW E2-26.5 drill pad (Figure 55), and the other looking northeastward toward the <br />MDW E2-30.5 drill pad (Figure 56). These views provide great opportunities to observe hillside <br />conditions over Longwall Panel E2 while longwall mining occurs beneath this area. Overburden <br />thickness above the E-seam in this area is between 700 and 800 feet. <br />831-032.791 Wright Water Engineers, Inc. Page 60 <br />April 2010