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solids within the alluvium. The probability of this occurring is minimal. The • sediment control system at the King Coal Mine has been designed [o minimize impacts to the prevailing hydrologic balance at and near the permit area. All surface runoff from the mine area will flow, via a series of conveyance culvetts and ditches. to the sediment ponds, which are located on either side of the combina[ion haul/access road adjacent to the alluvial valley. The sediment ponds, which are adequately sized to contain the runoff from a 10-year, 24-hour storm. will not discharge until a storm event of this magnitude has been exceeded. National King Coal has committed to an extensive water quality sampling plan, should the ponds discharge due to mine portal discharges. The sampling plan should be an effective method of determining the extent, if any, of impacts which are occurrine to the alluvial aquifer system. It is thought, that, due to the great quantity of water vanspotted within the alluvial aquifer, the effects of surface drainage to the AVF will be immediately mitigated. IV. Topsoil Information pertaining to baseline soil inventory is presented in Section 2.04.9 of the permit application. Informationpertaining to topsoil replacement is presented in Section 2.05.4. No baseline surveying of the soils was performed in the mine facilities area due to previous disturbances. Instead, a survey by the Soil Conservation Service was • performed for adjacent, undisturbed areas. This survey identified three soil mapping units as addressed in Section 2.04.9 and depcted on Map C-6 of the permit application. Approximately 1.5 acres are to be disturbed at the end of the life of mine as a topsoil borrow area. The owner of the land has allowed access and rights for a topsoil borrow ar® to be used for reclamation purposes. All available topsoil and suitable growth medium have been analyzed and the results are located in Appendix 9. The location of the topsoil borrow area is indicated on Map C-4. V. Sealing of Drilled Holes and Underground Openings Information pertaining to the sealing of drill holes atd portal and ventilation openings is presented in Section 2.05 of the permit application. All portal and ventilation envies will be permanently sealed by backfilling each opening with underground development waste, common fill, and sediment from the two sediment ponds for a distance of 50 feet from the entrance. Once backfilling its completed, each entry will be collapsed with explosives. National King Coa] has adequately demonstrated that sufficient quantities of fill material exist on site to complete both portal and mine bench backfilling activities. [] 17