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The sampling and suitability evaluation was conducted by James Nyenhuis, Certified Professional Soil <br />Scientist 'The 2007 Soils Report is attached and provides the detailed write-up, analytical data, and sampling <br />locations From the 2007 sampling effort. <br />• <br />• <br />• Topsoil Balance <br />SCC submitted a topsoil balance with Permit Revision 04 (dated 9/04). A topsoil balance is completed to <br />ensure topsoil is salvaged, stockpiled, and replaced as recommended and approved in the permit, and, if <br />necessary, to readjust the topsoil salvage and projected replacement thickness. The topsoil information is also <br />used to update the topsoil volume information previously submitted and adjust the mean topsoil replacement <br />thickness based on topsoil depth samples. <br />Topsoil Salvage and Storage. The life-of--none disturbance from which topsoil was salvaged (1,381.5 acres) <br />and the topsoil stockpile sites as of December 31, 2007 are shown the 2007 Topsoil Replacement map. <br />"1"lie actual volume of topsoil salvaged and stockpiled from 1989 through December 31, 2007 was detern~led <br />by field suraey of existing topsoil storage stockpiles. The stockpile volumes as of December 31, 2007 are <br />listed i11 Tab1e07.1, Topsoil Stockpile Volumes. As of the end of 2007, 75.5 acre-feet of topsoil remain <br />stockpiled in the mining area and 73.1 acre-feet of topsoil are stockpiled along the Tie-Across Haul Road. <br />Topsoil Replacement. Topsoil was replaced on 144.4 acres of disturbed area during 2007. Therefore, the <br />total remaining mine disturbance area requiring topsoil (as of December 31, 2007) is 84.6 acres. <br />Topsoil Replacement Thickness. The overall topsoil replacement thickness for the II-W disturbed area <br />was originally projected to be 1.3 feet for the mine area and 0.7 feet for the Tie-Across Haul Road. The <br />topsoil balance for the remaining disturbed was calculated as Follows: <br />Mine Area <br />Total Disturbance .dreg <br />Permanent Facilities & '1 opsoil Replaced <br />Disturbed area requiring topsoil <br />Topsoil in stockpiles (Table 07.1) <br />Mean Replacement Depth <br />= 1,284.9 acres <br />= 1,200.3 acres <br />= 84.6 acres <br />= 75.5 ac-ft <br />= 0.9 feet <br />(10.8 inches) <br />Tie-Across Haul Road <br />Total Disturbance urea <br />Topsoil in stockpiles (Table 07.1) <br />Mean Replacement Depth <br />= 96.6 acres <br />= 73.1 ac-ft <br />= 0.7 feet <br />(9 inches) <br />Tab 21, Minesoil Reconstruction, in the PAP, indicated an estimated average of 1.3 feet (15.6 inches) would <br />be replaced over final graded spoil in the North II-W area, however sampling measurements show that 22.9 <br />inches were actually replaced. This indicates that more topsoil was removed during initial disturbance than <br />was originally anticipated. <br />Tab 21, Minesoil Reconstruction, (I'R-05) indicated an estunated average of 1.6 feet (19.2 inches) would be <br />replaced over final graded spoil in the South II-~~ area, however, 2005 sampling measurements showed that <br />22.1 inches were actually replaced, while the 2006 measurements indicated that the replacement depth was <br />reduced to 15.7 inches for an overall average of 22.1 inches. Permit Revision 05 and discussions with the <br />Division have determined that variable replacement thicknesses over the remaining area would be desirable. <br />As shown in the topsoil balance above, a minimum average replacement thickness of 10.8 inches can be <br />achieved. <br />2 <br />