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<br />10 <br />18. Information in the permit application documents the comparability between the <br />major pre-mine vegetation types sampled in 1980 (mountain shrub and sagebrush) <br />and their respective reference areas. In 1988, additional areas of these two <br />vegetation types were sampled, in conjunction with Permit Revision No. 1, which <br />incorporated an additional 1878 acres and two additional pit areas. Based on data <br />summaries in Table 3 and Table 4 of the permit application, it would appear that the <br />pre-mine areas sampled in 1988 exhibited significantly higher cover and production <br />thaw the respective vegetation types sampled in 1980. The extent to which the <br />differences reflect annual precipitation variation as opposed to "real" differences is <br />not ]mown, nor is it known if the reference areas were sampled in 1988. <br />Information documenting the statistical comparability in terms of vegetation cover <br />and herbaceous productivity between the 1988 sampled areas and their respective <br />reference areas, pursuant to Rule 4.15.7(3)(b), should be submitted for inclusion in <br />the permit application if available, or an explanation addressing why such <br />demonstration was not made should be provided. <br />19. On Page 4.15-12 on the application it is stated that comparisons of weighted averages <br />under subsection 4.15.7(4)(b) will be utilized to determine revegetation success, and <br />that the same methodologies and statistical tests used to compare premine and <br />reference areas will be used to compare reference areas and revegetated areas. <br />It is suggested that additional detail be provided with respect to sampling design <br />approaches, sample adequacy determination, and statistical testing pursuant to Rule <br />4.15.7(2)(c). The referenced weighted averaging approach requires certain <br />modifications to the statistical tests employed for pre-mine comparison, and there has <br />been some evolution in the Division's recommended approaches to sample adequacy <br />determination and statistical testing. The operator is referred to the Division's <br />recently issued "Guideline Regarding Selected Coal Mine Bond Release Issues". <br />20. The species diversity success standard as set forth in the application is a species <br />composition based standard derived from the weighted relative cover values of the <br />four principle species documented in the pre-mine sample data. The 4 species <br />included three cool season grasses and 1 perennial forb. The standard would require <br />that at least 4 principle species of the same life form and seasonal variety as <br />identified in the pre-mine data be established on the reclaimed area, and that the 4 <br />species combined contribute at least 43.4% to the diversity of the postmining area <br />(i.e. 43.4% combined relative cover). <br />The standard as described could be interpreted in such a way as to be essentially <br />meaningless. For example, a reclaimed area could be dominated by a single species <br />contributing 99.7% relative cover, with three other species contributing .1% relative <br />cover each. If the four species included three grasses and a forb, an argument could <br />be made that the standard had been met, even though the reclaimed stand would in <br />