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Soil Reo l acement Thickness. Peabody is required by CMLRD to closely observe and routinely • inspect soil replacement thickness in the wedge and wolf Creek reclamation areas at Seneca II Mine. This monitoring requirement is included as Item 5 of the Topsoil Quality Lontrol Program presented in Tab 9, Attachment 9-4, Page 9-41 of Permit C-80-005. Nistorical soil replacement thickness information for the 1984 thru 1989 reclamation blocks is presented in cable 9-4-3, Attachment 9-4, Tab 9 of Permit C-80-005 and the Second, Third, and Fourth Annual Topsoil and Spoil Monitoring Reports for the 1987, 1988, and 1989 field seasons (PCL, 1987; 1988; 1989). Soil replacement thicknesses were measured July 10, July 11, September 24, and October 18 for all reclaimed areas which had topsoil replaced during 1990 and 1991. Sample sites were located on a 1" 400' topographic map (dated 10/10/89 and 12/11/90) utilizing a 300 foot 60° slant grid system. Wolf Creek and wedge sample sites were independently numbered from each other but sequentially numbered with Table 5, presented in the Fourth Annual Topsoil and Spoil Monitoring Report (PLC, 1990). A 2-3/4 inch bucket auger was used at each site to excavate a pilot hole through the entire soil strata. An abrupt boundary, defined by color and rock fragment content, typically occurred at the soil/spoil interface. The replaced soil thickness was measured through the pilot hole immediately after encountering the spoil The data collected for the 1990 and 1991 field seasons is presented in Table 91.3. Sample sites are shown on Exhibit 91.2. Soil thickness ranged from 0.7 to 1.7 feet with a mean of ~- 1.1 feet for 61 sample sites. Operators have been instructed to replace approximately 1.1 to 1.2 feet of soil to compensate for shrinkage which occurs during resaturation and tillage operations. The minimum mean soil replacement thickness for bond liability is 1.0 feet. The soil thickness at Site w-276 is not representative and was not included in [he calculation of mean soil thickness. Site W-276 is actually the toe of existing soil stockpile Site P. Soil Balance. Peabody is submi t[ing [he soil balance with the Annual Reclamation Report as required by Permit L-80-005, Tab 13, Page 13-29c and as recommended by Section 2.04.13(2) of Colorado's Regulations for Coal Mining. The soil balance is completed to ensure that soil is salvaged, stockpiled, and replaced as recommended and approved in the permit, and, if necessary, to readjust soil salvage and redistribution thickness. The soil information is also used to update the soil volume information Peabody submitted with the 1990 Annual 9 ., 199f hR~2