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d) The Halandras landfill is already addressed in the permit. No other `excavated' disposal site is proposed. Non-excavated disposal sites potentially include al] shafts, road cuts, cuts at the D Portal, and slot storage. Demolition debris or other wastes will be covered a minimum of 2' in a manner consistent with Rule 4.11.4. e) No adverse impacts are anticipated in any of the potential disposal sites due to placement of demolition debris. Stability should not be effected considering the limited quantities relative to the quantity of fill involved and rigid characteristics of the demolition debris. Placement of asphalt or concrete material in the shafts, since some of this material would be loaded in trucks regardless, would be less prone to settling than natural materials. Hydrology would not be adversely impacted since the reclamation fill areas are well away from stream channels. In addition the materials aze not of a character adverse to water quality. Minimal impacts would result to post-mine contours. Even under the worst case scenario where everything gets buried the contours would change only a few feet, less than the error inherent to the engineering design. The character and appearance of the fill would not change as a result of the buried debris. 13. The language in Section V.L4.c has been modified to clarify where mulching would be required (page V-42). As suggested by DMG a drill site with 33% slope (3H:1V) was used as a basis to determine the need for mulch application. The equating LS factor in the RUSLE equation for such a site is 5.87, assuming a typical slope length of 100 feet and silt loam soils. Applying 2000 pounds per acre straw mulch reduces the correction factor to 1.41. To achieve this same correction factor without either mulching or extensive roughening would put the maximum slope at 10%. Many factors are involved in determining the potential for erosion on a given site and many options other than mulch are available to reduce erosion. Therefore, use of the RUSLE equation will be used to determine when mulching will be required for a given site. Mulching will be required when the correction factor of LS x C x P is greater than 1.4. Slo e % LS Mulch (C=0.24) Rou hness (P=0.15) LS x C x P >33% (5.87) X 1.41 <33% (5.87) X 0.88 <10% 1.38) 1.38 The timing of planting annual cover crops (stubble mulch) was also modified as suggested by DMG. As stated in DMG's response the costs for mowing can then be deleted. January I5, 2003 3 Permit Revision #4 Comments Blue Mountain Energy, Inc.