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All such calculations were based on data from a minimum of fifteen samples. <br />NOTES ON THE COMPARISON OF DATA TO APPLICABLE REFERENCE AREA STANDARDS <br />Corrections for Noxious Weeds and Excess Annuals <br />Upon the formal comparison of cover and production data from reclaimed areas to applicable performance <br />standards, observed total all -hit herbaceous cover percentage and collected production, must be adjusted <br />for excessive contribution by annual / biennial species (i.e. no more than 10 percent relative cover or <br />production, CDMG 1995, Guidelines Regarding Selected Coal Mine Bond Release Issues, 1(IV) A(4)). <br />Herbaceous cover and production values used in such comparisons also must exclude values for species <br />present on the Routt County Prohibited or Restricted Noxious list or that are listed as noxious by the State of <br />Colorado (Colorado Dept. of Agriculture, Division of Plant Industry, Title 35, Article 5.5, 101 -119, Lists A and <br />B of Rules as replaced 2003). For purposes of assessment of reclamation adequacy, all -hit herbaceous <br />cover data from reference area sampling is used as per SCC Mine permit provisions. <br />Upward Adjustment of the Mountain Brush Cover Standard <br />Sample adequacy for total vegetation cover was achieved for the reference areas and BRB -1. For 2011 <br />total allowable herbaceous cover, adequacy based on all -hit values was achieved for BRB -1, the Aspen <br />Reference Area, the Sagebrush Reference Area, the Steep Mountain Brush Reference Area and the <br />Western Wheatgrass Reference Area but it was not for the Mountain Brush Reference Area. For 2012 total <br />allowable herbaceous cover, adequacy based on all -hit values was achieved for BRB -1 and all Reference <br />Areas. <br />In consideration of the lack of a sample size sufficient to detect a 10% reduction in the mean with 90 % <br />confidence (i.e. sample adequacy), the upper limit of the possible values of the true mean (with a sample <br />size of 18 in 2011) was determined for the 2011 Mountain Brush Reference Area. This can be done either <br />by calculating the confidence interval for 90% confidence and adding it to the mean or by way of rearranging <br />the sample adequacy formula and solving for the detectable percent reduction then adding that to 100% <br />and multiplying by the mean. This is demonstrated in the Discussion section below. <br />It is also to be noted that the data from the five reference areas are weighted in accordance with the original <br />relative abundance of the types in the pre- mining landscape (11% aspen, 35% mountain brush, 31% <br />sagebrush /snowberry, 13% steep mountain brush and 10% western wheat). In the process of weighting, a <br />reliable estimate of variance is lost. Thus the reference area standard thereafter in the process is treated as <br />a technical standard (i.e. without confidence limits) and one - sample t- testing is used. <br />6 <br />