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Mr. Dennis Conn - 2 - June 20, 1989 A. Abandonment Seals: (continued) For these reasons, the Division believes the aoolication should specifically address the hydrologic implications of the orooosed B-Seam mining for the approved hydrologic sealing and abandonment plan. If appropriate, necessary modifications, including specified locations and seal designs for the shaft, inclines, and within the B-Seam and E-Seam workings should be included. B. Amendments to the F-Seam Mine Plan The permit revision aoolication includes several F-Seam mine plan amendments as depicted on Exhibit 3.4.48.2, entitled "F Seam Mine Plan". The first is the designation of three small room and pillar panels 1S, 2S and 35, off the Northwest Submain Entries. This area of extraction immediately adjoins the main N-S entries immediately inside and to the west of the F-Seam portals. The amended map indicated targeted extraction in 1990 and 1991. This area was designated for extraction in the original 198D mine plan. Since then myriad mine plan modifications realigned the main entries and postponed extraction in this area. In the mine plan submitted for the permit renewal in 1986, no panels were depicted in this area. As the applicant observes, these orooosed panels and submains underlie the site of the approved Upper Waste Pile. The application projects that the Lower Waste Pile can accommodate the expected waste production through the year 2002, and that subsidence due to undermining in the F-Seam should have ceased in the interim. WECC applied for a permit revision to allow the construction of an Upper Waste Rock Pile in October of 1984, The operator had noted its intention to construct an upper waste pile in the original permit aoolication. The permit revision application represented the submission of a detailed engineering plan for that structure, for which a general plan had earlier been submitted. WECC orooosed to construct a five million ton coal processing waste oil e. The completed upper waste pile strut w re would cover approximately 40 acres, and attain a maximum thickness of 160 feet. At the request of the Division, West Elk Coal Company had completed an analysis of the potential stability affects upon the F-Seam, from the placement of a five million ton surcharge load upon the existing workings within the mine. The plan called for approximately the eastern half of the waste pile to be undermined. The waste disposal pile was designed with five Granular underdrains, designed to prevent saturation or invasion of water into the waste pile. The operator also agreed to install several survey monuments to monitor slope stability of the completed structure and adjoining areas. The original permit application included a statement of intended possible secondary mining of coal beneath the coal pile. In order to assure the assumptions made in completing the stability analysis were correct, the Division imposed several stipulations upon approval of the Upper Waste