2010-05-26_REVISION - C1981008 (3)

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C- 1981 --008 - SL -12 Prelirm'nary Adequacy Review May 2010 Page 6 of detailed presentation of data, sampling methods, statistical demonstrations of success, and summary discussion of study results. Please revise the narrative on the as appropriate. 9. In accordance with the bond release guideline (page 11 and 12, Items 1 and , please provide a narrative summary of the reclamation and management history of the parcels included in the Phase III release request, including narrative regarding achievement of the approved post - ruining land uses. In addition, please provide narrative addressing the "quality standard" of the approved permit for irrigated pasture i.e. that "at least 75% of the relative production will be comprised of seeded species or species of comparable quality as livestock forage). Because production data vas not collected by species, conformance with this requirement may need to be based in part on inference from the vegetation relative cover data. 10. Please provide cover summary tables, to supplement the spreadsheet Tables Al and A2, in the data section of the vegetation Report (refer to Item 3, above, for detailed explanation of the request). 11. 2007 EP production success demonstration is presented on pages 11 and 12 of the Phase Vegetation Deport. Summary information including statistics is presented in "Table 2, page 11. Sample Data is presented in Table A3 (reference area) and Table A (reclaimed area). The reclaimed area production sample mean exceeded the reference area sample mean by a wide margin, and because sample adequacy was not' demonstrated in the reference area, a 2- sample reverse null t -test was properly selected to demonstrate that the difference was statistically significant i.e. that the reclaimed area true mean exceeds the reference area true mean). The various fonnul s associated with the t -test demonstration are presented in their correct and proper form in equations 4, 5, and 6, on pages 8 and 9 of the report. In the calculations however, there were a couple errors, one nn and one more significant. a In Table 2, the Table t-statistic used for comparison to the calculated t- statistic is the t value for an alpha error probability of o.1. This value is more stringent than the alpha error probability level of 0.2 allowed by Rule 4.15.11(2)(c), and specified in Equation 61, on page 9 of the Vegetation Report. This is a minor error, which would work to the disadvantage of the operator.' b The more significant error is that, apparently, a parenthesis was inadvertently omitted from the t -test formula. of Equation 6 when it was entered into Excel as formula. This resulted in an erroneously high value for the calculated t- statistic (3,705.304), as reported in Tabl 2. The Division independently entered the data and ran the statistical tests for the 2007 IP production data in Excel, with the spreadsheet data. . Our results are presented in Attachment 2 to this memorandum. The calculated t- statistic we obtained was 4.7. Since 4.7 is greater than the table t- statistic of 0.847 (for alpha error probability of 0.2 ) the conclusion remains the same; reclaimed area mean production is greater than 90% of reference area mean production. We were able to intentionally create the parenthesis' error and obtained the same erroneous