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Peabody Sage Creek Mine <br />SL -3 Phase III Bond Release Request <br />July 2014 <br />Note that the Phase III BRB PSCM -1 reclaimed unit did not require adjustment for annual <br />composition in either 2010 or 2011 similar to the native sagebrush and mountain brush reference <br />areas. This provides additional demonstration that the reclaimed areas are well established. <br />2010 Herbaceous Production Success Evaluation <br />The 2010 herbaceous production values for the mountain brush and sagebrush reference areas <br />are summarized in Table 5 above. Calculation of 90 percent of the production performance <br />standard appropriate for 2010 sampling is demonstrated below. <br />Mountain brush reference area allowable herbaceous production = 483.6 lbs /acre <br />Sagebrush reference area allowable herbaceous production =874.3 lbs /acre <br />90 percent of the Production Standard = 0.90 [0.83(483.6) + 0.17(874.3)] = 495.0 lbs /acre <br />The 2010 BRB PSCM -1 mean allowable herbaceous production of 1973.5 pounds per acre (Table <br />5) exceeds 90 percent of the production performance standard. Average annual and biennial <br />BRB PSCM -1 sampled production was not greater than 10 percent of total herbaceous <br />production and therefore no "excess" annual /biennial production deduction was used in 2011. <br />Noxious weed production was not collected. <br />While the 2010 BRB PSCM -1 allowable herbaceous production exceeded 90 percent of the <br />production performance standard, 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 2010 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 />Appendix C in the vegetation report contained in Attachment D to this document for additional <br />information. <br />A reverse -null t -test of the assertion that the 2010 BRB PSCM -1 allowable herbaceous <br />production exceeds the Weighted Reference Area allowable herbaceous production performance <br />standard is as follows: <br />12 <br />