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Topsoil Replacement Thickness. The topsoil balance as of December 31, 2012 for the <br />remaining life -of -mine is calculated as follows: <br />Mine Area <br />Total disturbance area <br />Permanent Facilities & Topsoil replaced <br />Disturbance area requiring soil <br />Soil in stockpiles (Table 12.1) <br />Mean replacement depth available <br />By dividing the topsoil available by the area requiring topsoil replacement, we arrive at the <br />future topsoil balance thickness of approximately 2.3 feet for the remaining disturbance area. <br />This generalized topsoil balance does not account for any area variations or for permanent <br />facilities not requiring topsoil; it is strictly an area -wide average. <br />During 2007, topsoil thickness sampling was conducted over the topsoiled area on a 500 ft. <br />grid. The overall topsoil replacement depth for the areas reclaimed to date is 21.4 inches. <br />The 21.4 inches is right in line with the original projections of 21.6 inches. <br />REVEGETATION <br />• Seeding and Shrub Planting <br />Seeding. No additional acres were seeded for the first time in 2012. <br />Shrub Planting. There were no shrubs planted in 2012. <br />• Monitoring <br />ESCO Associates, Inc conducted revegetation monitoring of permanently revegetated areas <br />during the summer of 2012. The 2012 Annual Revegetation Monitoring report will be <br />submitted under separate cover. <br />• Weed Control <br />= 848.6 acres <br />= 840.4 acres <br />= 8.2 acres <br />= 41.2 acre -feet <br />= 2.3 feet (28.1 inches) <br />Survey for noxious weeds was carried out on the Yoast Mine permit area in 2012. Monitoring <br />was conducted in 2012 to determine the need or level of retreatment necessary for areas <br />sprayed in 2011. Canada thistle was the primary target species in all control areas, with lesser <br />activity directed towards areas of hounds tongue and whitetop. Control areas were sprayed in <br />August and September. A spot spray gun was used to concentrate control activities on target <br />areas, reducing potential impacts to adjacent desirable vegetation. The herbicide mix, based <br />on recommendations from the Colorado State Extension Service, was mixed and applied by a <br />certified commercial applicator. The weed control areas will continue to be monitored in <br />2013 for effectiveness and necessary retreatment. See attached 2012 Weed Control (daily) <br />Log and the 2012 Weed Spray Location map for a detailed description and location of the <br />2012 herbicide application. <br />• Grazing <br />7 <br />