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~. BACKFILLING 8 GRADING: Approximate Original Contour - Williams Fork Strip Pit No. 2 The applicant requests an amendment to the currently approved post-mining topography of the Williams Fork Strip Pit No. 2. A proposed post-mining topography was approved as a portion of Permit C-81-044. The approved configuration requires the regrading of approximately 240,000 cubic yards of spoil. The applicant was allowed to postpone final grading, because the installation of a second set of portals for the No. 9 Mine was proposed at this location. The applicant's proposed reconfiguration of the post-mining topography for the pit requires the regrading of approximately 40,000 cubic yards of spoil and results in a valley form considerably more steeply sloped than the approved configuration. I do not believe that the amended topographic configuration compliments the natural character of the area. I also believe it may present some erosional stability problems because of steep slope gradients. Therefore, I recommend its denial. At a rtiinimum, the applicant will need to demonstrate that their proposed amendment satisfies the requirements for approximate original contour. Disposal of Underground Development Waste - No. 9 Portal The applicant requests permission to dispose of underground development waste within the existing No. 9 Portal incline excavation. These portals are proposed to be sealed and abandoned. The approved reclamation plan calls for the backfilling of the existing excavated incline. The applicant proposes to utilize the excavation to dispose of waste, which would incT•ease the volume of waste their plan would accommodate. I believe that this is a desirable amendment to their plan, if properly executed. Because there would be no elevated embankment, slope stability is not a concern. Howc>ver, I am concerned that ground waters might invade the unencapsulatecl waste, producing a potentially detrimental leachate. Dampness has been noted on the slopes of the portal excavation in the past. The application fails to quantify the amount of waste which would be accommodated at the site. The applicant should provide more detail concerning the preparation of the site and the placement of the waste material to preclude possible problems. The applicant should thoroughly address the possible hydrological implications of the proposed waste disposal. If the applicant can satisi`y water quality criteria, then I would have no objection to the proposal. [f necessary to preclude detereoration of ground water quality, the waste could be encapsulated in impermeable material. SUBSIDENCE Summary The application includes a life-of-mine plan which projects coal extraction in both the No. 5 and No. 6 mines. The preferred mining method is longwall, but the applicant requests the right to substitute room and pillar techniques to supplement extraction. Because of the efforts necessary for initial development, projected subsidence is relatively limited within the initial