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The post-mining land-use at the Colowyo mine is rangeland and wildlife habitat. The Phase II <br />Bond Release areas of the East Pit, West Pit and Section 16 Pit were walked during the <br />inspection. No bare spots or problem areas (with the exception of the exclusion areas) were <br />observed. While Colowyo has not used the reclaimed lands for domestic livestock grazing, there <br />is a large, resident elk herd that uses the reclaimed lands extensively. There are also several <br />smaller herds of deer and pronghorn that use the reclaimed East Pit, West Pit and Section 16 Pit <br />areas. The wildlife use includes grazing (including winter grazing) and calving areas. <br />Soil Loss <br />Pursuant to Rule 3.03.1(3)(b), "No more than sixty (60) percent of the bond shall be released so <br />long as the lands to which the release would be applicable are contributing suspended solids to <br />streamflow or runoff outside the permit area in excess of premining levels as determined by <br />baseline data or in excess of levels determined on adjacent nonmined areas..." In their SL-04 <br />application, Colowyo provided a demonstration of pre-mining and post-mining sediment loss for <br />the Phase II Bond Release areas. The demonstration used the Revised Universal Soil Loss <br />Equation (RUSLE), which is a method for demonstrating pre-mining and post-mining soil loss <br />approved by the Division. <br />The pre-mining sediment yield from the Phase II reclamation blocks was calculated at 79.4 <br />tons/acre/year. The post-mining sediment yield for the Phase lI reclamation blocks was <br />calculated at 67.2 tons/acre/year. Since the post-mining soil loss is less than the pre-mining soil <br />loss (approximately 85% of the premining level) the Division finds that the reclaimed Phase II <br />Bond Release lands are not contributing suspended solids to streamflow in excess of premining <br />levels. <br />Exclusion Areas <br />Based on the bond release inspection of the Colowyo Mine and based on a review of yearly <br />vegetation monitoring reports contained in the SL-04 application and Colowyo's yearly Annual <br />Reclamation Reports, the Division is proposing to exclude two areas from the Partial Phase 11 <br />Bond Release. The Division is proposing to exclude reclamation block WPO10 (5.7 acres) in its <br />entirety and the northeast portion of reclamation block EP041 (6.1 acres). These two areas are <br />being excluded from the Phase II Bond Release due to high concentrations of annual brome <br />(cheatgrass) cover with little to no perennial cover within these areas. The exclusion areas <br />reduce the bond release area from 432.7 acres to 420.9 acres. There is no proposed reduction in <br />the Phase I Bond Release acreage. Figure 3 shows the location of the proposed exclusion areas. <br />Summary and Conclusions <br />The Division has completed its review and evaluation of the SL-04 application submitted by CCC <br />for the Colowyo Mine. The Division will propose a partial Phase I Bond Release on 494.2 acres <br />and a partial Phase II Bond Release on 420.9 acres. The Division is not proposing to release any <br />drainage channels or ponds or other lands not specifically shown or described in this document. <br />Proposed Decision and Findings of Compliance 2 May 2011 <br />Partial Phase 1/11 Bond Release SL-04 Page 12