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Walker to File C-81-019, SL-03 <br />• August 15, 2001 <br />Page 3 of 9 Pages <br />returned to equivalent levels of yield as nonmined lend of the same soil type on the surrounding area <br />under equivalent ntanagentent practices as deterntined from the soil survey performed under 2.04.12 <br />and 2.06.6 and the success deterntination methodology of 4.25.5(3)(a); or, on alluvia[ valleyJloors, <br />until the essential hydrologic functions and agricultural productivity ]rave been reestablished. The <br />firs[ four lines of this rule apply to this application. The PAP (pages 4.15-4 and 5) requires <br />comparison to premining conditions as established by reference areas. The initial application <br />proposed comparison to cover values estimated for runoff in design of sedimentation ponds. As an <br />adequacy item, the applicant was asked [o resubmit the request using reference area cover data from <br />the Phase Ii vegetation surveys and to make other revisions as outlined below. <br />R values relate to erosivity of rainfall and runoff. Values of 19 aze used for all four study blocks for <br />both premining and postmining conditions. This value was accepted in the PAP Exhibit 7 Item l4 <br />Paragraph 2.1 page 3, and is considered appropriate to this analysis. <br />K values relate to soil erodibility. K values for various classifications of topsoil were accepted in the <br />PAP 9Exhibit 7 Item 13. K values for the study blocks used in the analysis (Table 6 Page 17) are <br />weighted values for K values of soil types (see Table 6a of the Application, page 18). An adequacy <br />statement was generated as follows: <br />• The K values listed in Table 6 Page 17 of the Application are weighted values from Table 6a Page <br />18 of the Application. Please change the Explanation/Units entry for K values in Table 6 Page 17 <br />to read "Weighted Values, Table 6a, RUSLE vers. 1.06 Application". Please renumber Table 6 to <br />read 6a on page 18 of the Application. <br />The applicant's response of May 15, 2001, was adequate. <br />K values in Table 6a (right hand column) are from Table 2 Item 13 Exhibit 7 of the PAP and are <br />considered appropriate to this analysis. <br />LS values are based on topography of the study blocks in both premining and postmining conditions, <br />and are considered appropriate to the analysis. For clarification, the following suggestions were <br />submitted to the applicant as an adequacy item. <br />For clarification, please add to the ExplanationNnits entry in Table 6 (page l7) of the Application <br />for LS so as to read: RUSLE vers. 1.06 Application Table 8 <br />The applicant's response of May 15, 2001, was adequate. <br />C values of the initial application were based on values selected for design of sedimentation ponds. <br />The PAP pages 4.15-4 and 5 state that reference area data is to be used. An adequacy item is as <br />• follows: <br />