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where acid strata (pH <5 and ABP <-5) are encountered. The monitoring program is outlined on Pages b-153, b-153a, b-164, and 9-40 of the PAP. No spoil samples were collected from the 4olf Creek final graded area during the 1992 field season. The 22 acres graded during 1992 will be sampled prior to soil replacement during 1993. Areas topsoiled during the 1992 field season had been previously sampled and the spoil analyzed during 1989 end 1991. A two to three foot suitable spoil-subsoil topd ressing has been used since 1985 to cover acid spoil in the Wolf Creek mining area. The subsoil replacement areas are shown on Exhibit 92.4. Limestone amendments have not been used to neutralize the acid spoil. Soil Reol acement Thickness. Peabody is required by CDMG to closely observe and routinely inspect soil replacement thickness in the Wadge and Wolf Creek reclamation areas at Seneca II Mine. This monitoring requirement is included as Item 5 of the Topsoil Quality Control Program presented in Tab 9, Attachment 9-4, Page 9-41 of Permit C-80-005. Historical soil replacement thickness information for the 7984 thru 1991 reclamation blocks is presented in • Table 9-4-3, Attachment 9-4, Tab 9 of Permit C-80.005, the Second, Third, and Fourth Annual Topsoil and Spoil Xonitoring Reports for the 1987, 1988, and 1989 field seasons, and the 1991 Annual Reclamation Report (PCC, )988; 1989; 1990; 1992). Soil replacement thicknesses were measured September 18 and October 6 for all reclaimed areas which had soil replaced during 1992. Sample sites were located on a 1" = 400' topographic map (dated 10/03/91) utilizing a 300 foot 60° slant grid system. Wolf Creek end Wadge sample sites were independently numbered from each other but sequentially numbered with sites presented in previous reports. 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 et the soil/spoil interface. The replaced soil thickness was measured through the plot hole immediately after encountering the spoil. The data collected for the 1992 field season is presented in Table 92.1. Sample sites ere shown on Exhibit 92.2, Soil and Spoil Monitoring Mep. Soil thick ness ranged from 0.8 to • 1.7 feet with a mean o f 1.1 feet for 47 sample sites. Operators have been instructed to replace approximately 1 .1 to 1.2 feet of soil to compensate for shrinkage which often 3