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Colowyo C- 1981 -019 <br />10 Nov 2009 <br />Pg 5/7 6�� <br />Backfilling and Grading: - The area that was backfilled and regraded in the East Pit <br />this summer (approximately 35 acres) remains stable. Colowyo has cut five distinct <br />contour ditches into the reclamation on the north portion of this reclamation and the <br />water from these contour ditches will flow into the Prospect Ditch. No contour <br />ditches were cut into the south portion of the reclamation (by the Final East Pit Ditch <br />and the North Tributary, East Pit Ditch). The area has had the topsoil replaced and <br />was reseeded last month (October 2009). Topsoil depth verification was completed <br />in September 2009 and can be viewed in that month's DBMS inspection report. <br />- The area that was backfilled in the North Taylor area of the West Pit (approximately <br />55 acres) was walked and 53 elevation points were taken to compare with the <br />approved post- mining topography (Map 19). All of the elevation points were taken <br />with a Trimble GeoXT and are relative elevations, as they are not based on a control <br />point. There is some variance between the slopes extrapolated from Map 19 and <br />those derived from the GPS data gathered in the field. The chart below shows the <br />grade lines and the slopes from Map 19 and the Division's GPS data. See the <br />attached map for the location of these lines and see also the attached raw data for <br />these points. <br />GPS Pt <br />ID <br />Elevation <br />PMT <br />Elev <br />Grade <br />Line <br />Dist' <br />Elev. <br />Chng <br />Grade <br />PMT <br />Chng <br />PMT <br />Grade <br />0 <br />7113.2 <br />7115.0 <br />0 -4 <br />607.8 <br />65.0 <br />10.7% <br />120.0 <br />19.7% <br />4 <br />7048.2 <br />6995.0 <br />0 -10 <br />905.3 <br />50.9 <br />5.6% <br />5.0 <br />0.6% <br />8 <br />7062.3 <br />7110.0 <br />0 -14 <br />566.8 <br />131.5 <br />23.2% <br />85.0 <br />15.0% <br />10 <br />7038.0 <br />1 7100.0 <br />10 -15 <br />1,203.1 <br />112.6 <br />9.4% <br />85.0 <br />7.1% <br />14 <br />6981.7 <br />7030.0 <br />30 -20 <br />2,940.3 <br />228.0 <br />7.8% <br />280.0 <br />9.5% <br />15 <br />6925.4 <br />7015.0 <br />31 -41 <br />3,009.8 <br />240.2 <br />8.0% <br />240.0 <br />8.0% <br />19 <br />7026.4 <br />7045.0 <br />52 -42 <br />3,033.5 <br />216.0 <br />7.1% <br />175.0 <br />5.8% <br />20 <br />7053.3 <br />7080.0 <br />30 -52 <br />424.2 <br />98.8 <br />23.3% <br />160.0 <br />37.7% <br />24 <br />7152.8 <br />1 7225.0 <br />24 -46 <br />361.5 <br />79.0 <br />21.9% <br />65.0 <br />18.0% <br />30 <br />7281.3 <br />7360.0 <br />20 -42 <br />332.8 <br />86.8 <br />26.1% <br />55.0 <br />16.5% <br />31 <br />7245.7 <br />7285.0 <br />37 <br />7095.7 <br />7170.0 <br />41 <br />7005.5 <br />7045.0 <br />42 <br />6966.5 <br />7025.0 <br />46 <br />7073.8 <br />7160.0 <br />52 <br />7182.5 <br />7200.0 <br />A: Relative Elevation from Trimble GeoXT Handheld GPS Unit <br />B: PMT Estimated from Map 19 - Post - Mining Topography <br />C: Distance Measured from GPS Data <br />D: Relative Elevation Change <br />