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fee[. The subsidence projections and evaluation of potential related effects on the designated Fish Creek AVF aze • documented in Exhibits 7B, 7C, 4S and 46. During the initial mining of panel 6, well GWB-2 was subsided, as predicted, and the well was damaged and must be replaced. A replacement well (GWB-2R) will be installed adjacent to the existing well. The two wells will be monitored for water levels twice per week for a two week period, and thereafter only well GWB-2R will be monitored per the schedule presented on Table C of Exhibit 14. This joint monitoring would not be followed in the event that TCC is not able to obtain water levels from GWB-2 during the two week period. Well GWB-2 will be sealed with Volclay and permanently abandoned. Prior to permanently abandoning well GWB-2, the Division will inspect the well and provide Twentymile Coal Company with approval to abandon it. It is anticipated that a two inch well constructed with schedule 80 PVC materials will be installed adjacent to the existing well. The completion report will be forwarded to the Division. Originally, it was anticipated that room and pillar mining may be required to augment longwall production. However, at this time the major emphasis is placed in longwall production, therefore, the need no longer exists to identify a room and pillar area on the east side of the north mains. As shown on Map 23, and 23A, an additional longwall panel is being planned to the east of the north mains. It is planned to "neck-off' the initial 300 feet of the gate entries in July and August of 1990. The area then will be left until the mid 90's when the development work will be completed and the panel mined with the longwall. Approximately 60,000 feet of mains are expected to be driven during the life of the mine. Areal Extent The permit area of the underground mine, totals approximately 22,247.2 acres of which approximately 7,773 acres are affected. This area contains all the mineable coal reserves bordered by the l5% gradient cutoff line to the east • and west and the property line to the south. At the conclusion of mining, approximately 65% of all the coal contained within the mineable reserve area will have been extracted (see Maps 7, 8 and 9, Geologic Cross-Sections A-A', B-B' and C-C'). Minine Lavout The underground mine layout was designed with the objective of fast development, optimum access to outlying reserves and maximizing recovery and safety. Numerous physical, geotechnical and operational variables influenced the layout design. Mining activities are bordered on the east and west by lease boundaries, to the south by a lease boundary and mined out reserves and to the north by a l5% seam gradient cutoff limit. Reserve access is by a network of main entries oriented primarily north-south and east-west. Longwall panels are planned wherever geologically possible and consistent with safe and prudent mining practices. The following factors influenced the layout of the underground mine: Lease Boundaries -Limits the extent of mining extension. Geotechnical Characteristics -Including rock and coal strengths, jointing, cleating and quality. Structural Features -Major fault zones and steep gradients are avoided or crossed selectively. Reserve Access -Minimal development and capital cost and optimum men and materials transport. Orientation -Mains, submains and panels are oriented to avoid directions that have the potential for instability. Water -Inflow and control has been considered through sump location and updip development. Subsidence -Controlled subsidence is planned over areas of full seam coal extraction. ~\P~1R~-~rEY~ APR 2 4 2000 Permit Renewal No. 3 2.OS-13 i 1!1!99