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on acreage and projected salvage thickness for the affected soil types. If <br />experience has shown that original salvage volumes were over-estimated, it may <br />be reasonable to base salvage projections on the low end of the thickness range <br />listed for the deeper soil types, rather than the mid-point. For example, salvage <br />projection of 30" rather than 40" for Burnette soils, 25" rather than 35" for Work <br />soils, and 20" rather than 25" for Havre soils. <br />4. For verification purposes, and to provide early indication of the need for any future <br />adjustments in average topsoil replacement depths, please provide a permit <br />commitment to submit survey-based annual topsoil balance documentation (as <br />provided in amended Table 2.05-1 ), within each year's Annual Reclamation Report. <br />The topsoil redlstribution plan as described on current page 2.05-41 specifies a <br />"minimum replacement depth" of 12 inches in Section 11, and 18 inches in other areas, <br />with the exception of the CSU test plots and "selected areas" where topsoil may be <br />applied at depths greater than 18 inches. This section is inconsistent with the topsoil <br />balance presented in amended Table 2.05-1, and with the proposed average <br />replacement depth of 8 inches referenced in the cover letter and amended Section <br />4.06.4. It would appear that the lack of updates to this section was an oversight. <br />Please amend permit narrative on page 2.05-41, as warranted to incorporateTR-62 <br />soil balance projections. <br />6. Revised Section 4.06.3 text on amended page 4.06-3 states that "topsoil placement will <br />be performed as outlined on page 2.05-4, Table 2.05-1, Topsoil Schedule for Mining <br />Area" We note that the referenced table as amended is the soil balance as of October <br />2005. It is not a topsoil schedule based on projected volumes and acreages, as <br />presented in current Table 2.05-1. If additional topsoil schedule tables are provided <br />as requested in Item 3, text in this section will need to be properly amended to <br />refer to the new tables. <br />Revised Section 4.06.4 text on amended page 4.06-3 indicates that future topsoil <br />redistribution will be done at an average depth of 8 inches. Current text in Section 4.06.4 <br />refers to a uniform replacement depth of 18 inches throughout the mine site, whereas text <br />in the Topsoil Redistribution Plan on current page 2.05-41 references minimum <br />replacement depths of 18 inches in most areas, 12 inches in Section 11, and non- <br />specified "selected areas" where deeper topsoil might be applied. Given the temporal <br />and spatial variation in topsoil replacement depth requirements, clarification is requested <br />in order to eliminate inconsistencies and prevent future confusion with respect to bond <br />release demonstration. <br />Please amend the various text sections that discuss current and past replacement <br />depth requirements to be consistent. In addition, please amend Maps 28 and 28A <br />to delineate areas subject to specified "average" and (if applicable) "minimum" <br />replacement depth requirements for both past and future reclamation. <br />8. In the revised text of amended Section 4.06.4, there is a statement indicating that <br />"historical replacement depths for reclaimed area units are tracked in the Annual Report". <br />It is not clear whether this refers to tracking of applicable replacement depth <br />requirements, or actual monitoring based replacement depths. Also, we could not find <br />any replacement depth data for reclaimed area units in the most recent Annual <br />Reclamation Report. <br />Please provide further explanation regarding soil replacement depth tracking, <br />amend the text for clarification, and provide the referenced tracking data for <br />inclusion in the 2004 Annual Report, if it was erroneously omitted. <br />