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C-1981-008 - SL-12 Adequacy Review No. 4 5 May 2011 Page 9 of 10 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 value as the consultant, and this value (3705.3) is also listed on the Attachment 2 spreadsheet. c) The same minor error (use of alpha error probability value of 0.1 for table t-statistic), and the same more serious error (Excel formula error with resultant extremely high value for the calculated t-statistic) were both incorporated into the success demonstrations for the 2008 IP production data, the 2007 Dryland Pasture production data, and the 2008 Dryland Pasture production data. Please re-run the 2-sample reverse null t-tests for 2007 and 2008 IP and DP production success demonstrations using the appropriate .02 alpha error probability for the table t-statistic, and the corrected Excel formula for the calculated t-statistic, and revise Production Text Tables 2, 4, 6, and 8 with the corrected values. If the success results for any particular comparison change or are reversed based on the corrected test results, the corresponding "Comparison to Standard" narrative will need to be revised, along with other narrative sections of the application, as appropriate. With the Aug. 2010 response, the appropriate corrections were made to the Nest formula and the reclamation success statistical analysis was recalculated correctly. The tables were corrected. Item resolved. Soil Loss for Phase H The Division transmitted adequacy comments related to soil loss in a memo (effectively Adequacy Review No. 3) dated March 28, 2011. The comments, numbered as in the original memo, are incorporated below. In WPC's response, received on March 31, 2011, the soil loss comparison was revised. While the calculated sediment loss for the post-mining situation is actually larger than that for the pre-mining condition, the calculated soil loss values are so small that the Division agrees with WPC's argument that there is essentially no sediment loss for both pre-mine and post-mine conditions. Concerning the determination of the soil erodibility factor "K" on page 17, a statement is made that the soil on the reclaimed area is similar to the soil that was salvaged from that area before mining. However, comparison of the soil types listed in Table 1 on page 18 with the baseline soil types shown on soil Map 2.04.9-1 appear to show a couple of discrepancies. First, Barx soil and Ustic Torriorthents are listed in Table 1 but do not appear in the phase 2 release area shown on Map 2.04.9-1. Second, soil types Bowbac-Bowdish Complex, Haplargids-Endoaquolls Association, Bowdish-Bowbac Complex and Wahweap, map units 98D, 98F, 98G and 98H respectively, are shown on Map 2.04.9-1 in the phase 2 release area but do not appear in Table 1. Please explain. In the March 31, 2011 response, WFC revised page 18, and added a note to the bottom of Table I on page 19 to explain that NRCS soil survey designations were used for the soil loss comparison for SL-12, whereas the pre-mine baseline soil survey did not. An examination of the applicable soil types shown on the NRCS website verified the SL-12 soil type information. Item resolved. 2. For the cover factor "C" determination for the pre-mine condition for irrigated pasture, there appears to be a minor math miscalculation at the top of page 22. The final "C" factor of .0258 was obtained by adding .0008 to .025. It appears, however, that .0008 should be subtracted from .030, resulting in a value of .0292. If you agree, please revise pages 22, 23 and 29 accordingly. If you do not agree, please explain. WFC revised the methodology concerning the alfalfa cover in the March 31, 2011 response. This cover factor calculation is no longer needed. Item resolved. 3. For the cover factor "C" determination for the post-mine condition for irrigated pasture, there appears to be a minor math miscalculation in the middle of page 23. The change, however, would not affect the result but it