Laserfiche WebLink
12. BME provided properly amended language on revised page V-64, to include <br />updated references to Rule sections pertaining to statistical testing for <br />demonstrations of revegetation success. Item Resolved. <br />13. BME provided requested clarifications specifying comparisons of perennial <br />vegetative cover and perennial herbaceous production for demonstrations of <br />revegetation success, on revised page V-61. Item Resolved. <br />14. DRMS had requested additional information regarding the paired sampling <br />success demonstration procedure approved in the application for various "small <br />and linear features" and drill sites, including sampling approach, sample size, and <br />t-test details. BME addressed the issues of concern in the narrative response to <br />Item 14 in the TR-65 cover letter. However, the information was not included in <br />amended sections of the permit application. In general, the procedural <br />description, modified t-test formula and test statistic terms presented in the letter <br />appear to be appropriate and acceptable. <br />Clarification is requested regarding determination of adequate sample size, with <br />respect to paired sampling. Narrative indicates that minimum sample size would <br />be determined in accordance with Section 4.15.11(2) of the rules, and that both <br />the reclaimed and reference portions of the transects/quadrats would 6e subject <br />to sample adequacy requirements. In paired sampling, it is the difference values <br />between each set of paired observations (the "D" values) that provide the <br />pertinent statistics for determinations of success. Because the statistics used in <br />the t-test for paired sampling aze derived from the "D" values, the sample <br />vaziance and sample mean for "D" should also be substituted for the standard <br />sample variance and sample mean terms specified in [he sample size adequacy <br />formula listed in Rule 4.15.11(2)(a). It is not clear from the amended text or <br />supplemental narrative that the sample adequacy formula would be properly <br />modified with respect to paired sampling. We also note that, to conform with <br />regulation, the minimum number of paired observations would need to be 15, in <br />cases where the formula indicates a sample size smaller than 15. Minimum <br />required number of paired observations would be 30, in order to demonstrate <br />success using the "reverse null" t-test. Please include the information on <br />sampling procedures, statistics and formulas relevant to paired sampling <br />[including modified sample adequacy formula, minimum sample sizes <br />(minimum number of paired observations), and modified t-test formula] in <br />the amended permit application (either as expanded text or as an appendix <br />or attachment referenced in the text). <br />If you have any questions, please call me. <br />Sinc y, <br />~~~~ <br />K orham <br />Environmental Protection Specialist II <br />