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West Pit Fill Inspection Certification <br />On May 29, 2012, I inspected the area in which the West Pit Excess Spoil Fill is being constructed. <br />The purpose of this inspection was to observe the surface rock drain that borders the 3H:1V Excess <br />Fill Slope, inspect the areas dumped to final grade below the 7,400 dump elevation, inspect the <br />revegetation on the fill surface, inspect the fill for areas of water seepage or surface drainage, <br />inspect the final grade slopes below the 7,300 elevation of the Excess Fill Slope, and satisfy the <br />requirements of CDRMS Rule 4.09.10 (1a) and Rule 4.09.1 (1 b). <br />During the inspection, the face of the regraded fill was observed to be stable and unchanged from <br />prior inspections. All portions of the fill slope were visible. A small flow of about two gallons per <br />minute is evident from the toe of the underdrain. No erosion problems were noted. No other seeps <br />or springs were noted. <br />Since December, 2011, the 102 Dragline has been performing regrading activities near the top of <br />the West Pit Fill to begin to achieve the approved postmining topography. These activities <br />continued during this report period. The top of the fill has been reduced to below elevation 7430. <br />In addition, I reviewed the monument survey data collected May 15, 2012. These data indicate that <br />the elevations of most of the monuments have not significantly changed (typically less than 0.05 <br />feet of elevation change per calendar quarter). The most change was recorded at the 7150 West <br />monument. This site registered a decrease of 0.07 feet. Based on these data, the total <br />displacement of the monument is not of concern with regard to the stability of the dump. There was <br />also no evidence of structural weakness or other hazardous conditions associated with this dump. <br />These monument survey data are available for review upon request at the Colowyo Mine site. <br />I am a Licensed Professional Engineer in the State of Colorado and a representative of <br />Environmental Solutions, Inc, P. O. Box 2996, Cheyenne, Wyoming. Being familiar with the <br />Colowyo operation and the coal program permitting process in Colorado, the construction activities <br />related to the West Pit Excess Spoil Fill are in conformance, to the best of my knowledge and <br />experience, as specified in pages I a -2 through I a -4, Exhibit 19 I b and other applicable <br />requirements of the approved permit documents, a portion of CDRMS Permit C -81 -019. <br />xc: Mr. Kurtis Blunt <br />cf 17.15.1 <br />cf 24.20 (West Pit) <br />0 ,00 i <br />.7 -)R . <br />32 57 S ct <br />S ONAL V <br />HOMAS C P RS <br />P.E. No. 32257 <br />s/2-9 <br />DATE <br />