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Peabody Sage Creek Mine <br />SL -3 Phase 111 Bond Release Request <br />Y— (0.9 *Weighted Reference Area performance standard) <br />r 1973.5 — 495.0 = 8.05 <br />1006.4 <br />30 <br />July 2014 <br />Since critical t = 0.854 (one - tailed, alpha = 0.2, 29 df) and tc is greater than this critical value, <br />reclamation success for Phase III herbaceous production for 2010 is demonstrated. <br />2011 Herbaceous Production Success Evaluation <br />The 2011 herbaceous production values for the mountain brush and sagebrush reference areas <br />are summarized in Table 5 above. Calculation of 90 percent of the cover performance standard <br />appropriate for 2011 sampling is demonstrated below. <br />Mountain brush reference area allowable herbaceous production = 835.11bs /acre <br />Sagebrush reference area allowable herbaceous production = 1234.81bs /acre <br />90 percent of the Production Standard = 0.90 [0.83(835.1) + 0.17(1234.8)] = 812.7 lbs /acre <br />The 2011 Phase III BRB PSCM -1 mean allowable herbaceous production of 2815.8 pounds per <br />acre (Table 5) exceeds 812.7 pounds per acre, which is 90 percent of the production performance <br />standard. The average annual and biennial sampled 2011 BRB PSCM -1 production was not <br />greater than 10 percent of total herbaceous production and therefore no "excess" <br />annual /biennial production deduction was required in 2011. Noxious weed production was not <br />collected. <br />The 2011 BRB PSCM -1 allowable herbaceous production exceeds 90 percent of the production <br />performance standard but sample adequacy was not demonstrated with a minimum of 30 <br />samples taken in either the reclaimed or the reference areas. Therefore reclamation success for <br />Phase 111 2011 herbaceous production is demonstrated by passing a one sample t -test of Reverse <br />Null Hypothesis (CDMG 2005 proposed rules revisions 4.15.1 (2)(c)). Refer to the text and <br />13 <br />