1990-04-27_REPORT - C1980005 (3)

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' requirement is included as Item 6 of the Topsoil Quality Control Program presented in Tab ' 9, Attachment 9-4, Page 9-41 of the Seneca II PAP. Historical topsoil replacement depth information for the 1984 thru 1987 reclamation blocks is presented in Table 9-4-3, Attachment 9-4, Tab 9 of the Seneca II PAP and the Second and Third Annual Topsoil and Spoil Monitoring Reports for the 1987 and 1988 field seasons. ' Topsoil replacement depths were measured during September 1989 for all reclaimed areas which had topsoil replaced since October 18, 1988. Sample sites were located on a 1"=400, topographic map (dated 9/23/88) utilizing a 300 foot 60° slant grid system. Ylolf Creek and Wadge sample sites were independently numbered from each other but sequentially numbered with Table 7, presented in the Third Annual Topsoil and Spoil Monitoring Report. A 2-3/4 inch bucket auger was used at each site to excavate a pilot hole through the ' entire topsoil strata. An abrupt boundary, defined by color and rock fragment content, typically occurred at the topsoil/spoil interface. The replaced topsoil thickness was measured through the pilot hole immediately after encountering the spoil . ' The data collected during the 1989 field season is presented in Table 5. Samples sites are shown on Exhibit 1. Topsoil thickness ranged from 0.7 to 1 .9 feet with a mean of 1 .2 feet for 37 sample sites. Operators are currently instructed to replace approximately 1.1 to 1 .3 feet of topsoil to compensate for shrinkage which occurs during resaturation and tillage operations. The minimum mean topsoil replacement depth for bond liability is 1.0 ' feet. 1 The topsoil replacement depth was increased to greater than 1 .7 feet at 3 reclamation sites (see Table 5) to create suitable postmine micro-habitat soils for the development of shrub and aspen communities. Topography at these sites included swales and Swale sideslopes. Similar topography on premine landscapes typically has deeper soils (Wineveda ' or Coutis rather than Splitro) and mountain brush or aspen vegetation communities. 1989 Annual Topsoil Balance The following soil information is submitted to update the topsoil volume information ' Peabody submitted with the Third Annual Topsoil and Spoil Monitoring Report, to estimate topsoil replacement depths for the remaining disturbance areas at Seneca II Mine, to 1 identify topsoil replacement areas for each topsoil stockpile, and to satisfy the annual ' 6 PEABODY COAL COMPANY Western Dlvlslon