2012-11-14_REPORT - C1980007 (5)

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Longwall Panel E2. When observed during the spring 2012 field visit, there was no evidence of the road cracking observed the previous year. Observations noted along Traverse K -K' included a deeply incised rut (likely a partially healed subsidence tension crack) between the MDW E3 -36 and E3 -40 pads (Location 1), some compression bulging of a portion of the drill road to MDW E3 -36, and subsidence - related cracking along the east side of the access road to MDE E3 -32.5 (Location 2). In addition, seven shorter traverses that originate from Traverse K -K' were visited as part of the spring 2012 observations (i.e., K1 -K1', K2 -KT, K3 -K3', K4 -K4', K5 -K5', K6 -K6', and K7 -K7'). Traverse K1 -K1' is above both mined and unmined portions of E -Seam Longwall Panels E3 and E4 (Map 2). Traverses K2 -K2', K3 -K3', and K4 -K4' are above mined portions of E -seam Longwall Panel E2 (Map 2). Traverse K5 -K5' is above unmined portions of E -seam Longwall Panel E5 which will not be mined for at least another year. Traverse K6 -K6' is above the eastern ends of E -seam Longwall Panels E4 and E5 as well as above mined portions of E -seam Longwall Panel E3 (Map 2). Traverse K7 -K7' is located above mined E -seam Longwall Panel E3 immediately east of Traverse I -I' as shown on Map 1. The traverses are discussed in more detail below in Sections 4.5 through 4.11. 4.4.1 Location 1 831 - 032.794 November 2012 Spring 2012 Subsidence and Geologic Field Observations Box Canyon, Apache Rocks, and South of Divide Mining Areas This location is approximately 500 feet west of the MDW E3 -40 pad along Dry Fork Road. Along the centerline of the road at this location, a 30 -foot long subsidence crack was observed (Figure 6). Because of the illogical location along the centerline of the road, this site was almost overlooked as a tire rut. Considerable weathering is evident as precipitation and sediment collects in this depression and subsequently rounds off the edges of the crack. In places, this crack is up to 8 inches wide with a 10 inch depth below the rest of the road (Figure 7). Approximately 40 feet beyond the subsidence crack, there is somewhat of a continuation of this depression near the centerline. In this case, it appears this feature is the result of concentrated flow from the subsidence crack to the east. This area was mined beneath approximately 6 weeks Wright Water Engineers, Inc. Page 11