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2.05 APPLICATION FOR PERMIT FOR SURFACE OR UNDERGROUND MINING ACTIVITIES - MINIMUM REQUIREMENTS FOR OPERATION AND RECLAMATION PLANS. • Objectives No answer required. 2.05.2 Operation Plan - Estimated Area (1) Production Methods and Equipment Mining ceased at the Bowie No. 1 Mine on December 4, 1997. No production is scheduled from the mine during this permit term. Final reclamation of the surface facilities of the underground mine at both the East and the West portals is underway. The unit train loadout will remain operational throughout this permit term. The following provides a historical perspective of the mining that occurred at the East and West Mines. Mining practices were in accordance with the recommendations of the 0. S. Bureau of Land Management concerning Maximum Economic Recovery (MER). The mining method employed was room and pillar with partial pillar extraction from both panels and main entries when development was exhausted and mining conditions were practical. The mine workings are shown on Map 2-5 in Volume No. 2. Stipulation "g" Federal coal lease C-37210 stipulation "g" allowed only limited mining within 0 to 600 feet overburden zone depicted on Map 2-5. Additional mining constraints, developed as pillar stability design calculations, apply to the 600 to 600 feet overburden buffer zones also depicted on Map 2-5. These additional constraints were based upon recommendations contained in the June, 1983 subsidence study (Subsidence Appendix, Volume 3) conducted by Geo-Rydro Consulting, Inc. 0 to 600 feet of overburden i• • Only access entries are developed under Stevens Gulch and East Roatcap Creek drainages. • Permanent protective pillars were left standing to prevent all surface and subjacent disturbance to the overburden. • Protective pillars in these buffer zones are designed to provide safety factors in excess of 2.0 using the Wilson pillar design method. (See Pillar Stability Calculations in Volume 2) • Panel designs for specific development geometries and mining heights vary within these buffer zones and are optimized for MER, however the minimum safety factor criteria for all panels developed within these buffer zones remains constant at 2.0. • Secondary extraction or retreat mining is limited to the recovery of floor coal within previously developed entries. Permit Renewal - 1 - 01/03 RN-ov (y/9/oti~ /a1R-Id6