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Fall 2007 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />5.7 Traverse F-F' <br />Traverse F-F' begins at the fork in the Deer Creek and Dry Fork roads and continues southward <br />up the Deer Creek road to a locked gate near two stock water tanks in the upper Deer Creek <br />drainage near the middle of the NW'/o of Section 4, Township 14 South, Range 90 West. <br />The traverse is above the projected, and unmined, main mine haulageway and above unmined <br />longwall panel E4 to the northwestern edge of unmined longwall panel E6. The overburden <br />depth to the E-seam varies from 400 to 500 feet thick. Mostly light reddish gray to light brown <br />soil and alluvium (but some colluvium) derived primarily from clay and silt of the Wasatch <br />Formation was observed along the traverse. <br />The estimated thickness range of the soil, alluvium, and local colluvium is 50 to 150 feet. This <br />material is expected to yield without cracking during the mining of longwall panels E4 <br />through E6. Surface flow in Deer Creek was observed to decrease downstream from about 10 <br />gpm to zero even though there is no current mining in the area. The reduction of surface flow <br />over the 3,500-foot distance is likely the result of increased flow to the alluvium and bedrock <br />units underlying the valley floor. <br />Local springs, seeps, and ponds were observed along Dry Fork and Deer Creek. Flow in Deer <br />Creek and the level of the two existing stock ponds further south along the drainage was much <br />greater than observed during the summer of 2005. Estimated flows from springs and seeps has <br />decreased by about a factor often, when compared to the April 19 and 20, 2007 field visit. These <br />pre-mining changes are clearly the result of seasonal fluctuations. The observed changes were as <br />follows: (1) the flow from the spring in location 13 of the spring field visit has decreased from <br />15 gpm to 1 to 2 gpm (see page 29 of the spring 2007 report), (2) the spring flow at location 14 <br />of the spring field visit has decreased from 10 to 20 gpm to 1 to 2 gpm, (3) the flow at the stock <br />pond at location 15 (location 10 of this fall 2007 report) has decreased from 10 to 20 gpm to 1 to <br />2 gpm, and (4) the flow at the stock tanks (location 15 of the spring field visit and location 11 of <br />this fall visit) has decreased from 5 gpm to 0.5 to 1 gpm. <br />• <br />831-032.780 Wright Water Engineers, Inc. Page 42 <br />November 2007 <br />