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Seneca 11 Mine <br />SL -6 Phase 111 Bond Release Request <br />June 2014 <br />2011 <br />Mountain Brush RA' 2011 <br />21.0 (24.4)' <br />9.2 <br />21 <br />34 <br />1.345 <br />Sagebrush RA 2011 <br />44.4 <br />7.2 <br />15 <br />5 <br />1.345 <br />Phase III Bond Release BRB -5 <br />2012 <br />36.4 <br />9.2 <br />35 <br />11 <br />1.310 <br />Mountain Brush RA' 2012 <br />8.7 (10.7)' <br />4.8 <br />18 <br />53 <br />1.333 <br />Sagebrush RA 2012 <br />28.3 <br />5.8 <br />15 <br />8 <br />1.345 <br />Kepresents the upper hmit of the possible values of the true mean for the mountain brush RA. <br />As noted in the discussion above, a determination method was used for the mountain brush <br />allowable first hit herbaceous cover value used for calculations in establishing the cover success <br />standard. The 2011 and 2012 mountain brush reference area values in parenthesis in Table 3 <br />represent the upper limit of the possible values of the true mean using the sample data using <br />confidence level analysis. <br />The historical cover success standard at the Seneca II Mine is an area- weighted average of <br />allowable first hit herbaceous cover values determined from the mountain brush and sagebrush <br />reference areas. In recent years it was required by CDRMS to perform sample adequacy using <br />first hit herbaceous cover data. In the mountain brush, achieving sample adequacy using first hit <br />herbaceous cover data results in very high sample numbers as a result of high variability. The <br />mountain brush structure is dominated by a rather dense woody canopy, but may also have some <br />areas of relatively open canopy to the herbaceous understory. These characteristics contribute to <br />the highly variable first hit herbaceous cover data. Obviously, all hit herbaceous cover data (i.e., <br />multiple hits combined) would not be as affected. The previously discussed determination <br />method for arriving at a reasonable allowable first hit herbaceous cover value for the mountain <br />brush reference area addresses this and provides a technically valid resolution. The sagebrush <br />reference area, without the structural characteristics of the mountain brush, does not have this <br />issue and first hit herbaceous cover sample adequacy with reasonable sample sizes is attainable. <br />Calculation of 90 percent of the cover performance standard determined from 2011 and 2012 <br />I <br />