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C RESPONSE: • The discussion entitled, Backfilling Final Pit, has been rewritten to clarify the operations which will be typically performed. 2.05 Operations Plan 4. The swell factor calculations presented (Page 12-56) are a reproduction of the calculations presented in the original permit application. Since that time, the Division is aware of another swell factor calculations, which was presented in the 'Wolf Creek permit revision application. This second swell factor calculation modified the original amount from 15.3% to 14.8%. Due to the change in swell factor (and taking into consideration the discussion of this change on Page 12-11), the Division is uncertain as to the validity of the 15.3,°6 swell factor. Peabody Coal should perform a new calculation of swell factors to justify the 15.3% swell factor or a new swell factor. If a new swell factor is calculated, Peabody Coal needs to address the ramifications, if any, to post-mining areas and approximate original contour. RESPONSE: No new swell factor calculations have been performed. The two C different swell factors calculated in the past reflect two similar but • slightly different materials at different pit areas. The resulting landform currently existing at the mine site has not exhibited any. unusual adverse characteristics and has been generally acceptable. Any swell factor difference would be generally spread throughout the entire disturbed area. As an example, should the lJadge pit swell factor be 19.8 percent instead of 15.3 percent, the resulting increase in material volume would add an additional 1.5 feet of material over the entire area to be disturbed remaining in the Wadge East pit. This is insignificant and would not generally be observed in the field. Text has been added to reflect the methodologies used to calculate the swell factors. Tables and appropriate maps reflect the 15.3 percent and 19.8 percent swell factors applicable to the Wadge and Wolf Creek area pits, respectively. 2.05 Operations Plan 5. The discussion on Page 12-56 under the "Disposal of Excess Spoil" heading is somewhat misleading. Peabody Coal should riodify this section, referencing Pages 1L-10 to -13 of the Wolf Creek permit revision application which does discuss excessive spoil impacts. RESPONSE: The Disposal of d cess Spoil discussion on Page 1'2-56 has been • rewritten to•~eflee~ references to the Wolf Creek permit revision. 14 Revised 8/27/86