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DETERMINATION OF SAMPLE ADEQUACY <br />Sample adequacy for the data collected was evaluated based on total allowable live foliar herbaceous <br />cover using the following expression: <br />nmin = t2 — s2 <br />(dx)2 <br />Where: <br />nm;,, = minimum sample size <br />s2 = Sample variance (n-1 degrees of freedom) <br />d = Precision (0.10 for cover and production) <br />X = Sample arithmetic mean <br />t = The (a=.10) t -table value for a 1 tail t-test, n-1 degrees of freedom (infinite <br />degrees of freedom may be used if n>30) <br />n =Sample size <br />All such calculations were based on data from a minimum of fifteen samples. <br />NOTES ON THE DEVELOPMENT OF REFERENCE AREA — BASED PERFORMANCE STANDARDS <br />Corrections for Noxious Weeds and Excess Annuals <br />Upon the formal comparison of cover and production data from reclaimed areas to applicable <br />performance standards, observed total all -hit herbaceous cover percentage and collected production, <br />must be adjusted for excessive contribution by annual / biennial species (i.e. no more than 10 percent <br />relative cover or production, CDMG 1995, Guidelines Regarding Selected Coal Mine Bond Release <br />Issues, 1(IV) A(4)). Herbaceous cover and production values used in such comparisons also must <br />exclude values for species present on the Routt County Prohibited or Restricted Noxious list or that are <br />listed as noxious by the State of Colorado (Colorado Dept. of Agriculture, Division of Plant Industry, Title <br />35, Article 5.5, 101-119, Lists A, B, and C of Rules effective December 30, 2015). For purposes of <br />assessment of reclamation adequacy, all -hit herbaceous cover data from reference area sampling is used <br />as per SCC Mine permit provisions. <br />5 <br />