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County Road 65 was visually monitored on a daily basis by the operator during periods of <br /> undermining by"D" seam longwall operations, and repairs were made as necessary. Road <br /> segments subject to subsidence were posted with appropriate warning signs. Similar <br /> monitoring, repairs, and hazard signage are conducted during"B" seam extraction beneath <br /> the road. The stock pond reservoirs referenced above could potentially be impacted by <br /> tension cracks due to longwall subsidence (Raven Park and Halandras Reservoir No. 1). <br /> Lincoln Reservoir is located over a room and pillar mining area. Pillar dimensions and <br /> extraction ratio consistent with main entries will be employed beneath the reservoir to <br /> prevent subsidence. The stock ponds will be visually monitored during undermining, and <br /> repaired as necessary (see discussion in the Probable Hydrologic Consequences narrative <br /> of this document). The powerline is owned by BME, and the mine is the only customer <br /> served by the powerline. Power structures within areas of active subsidence will be <br /> monitored periodically by the operator, and repaired if necessary. <br /> The operator has calculated the maximum predicted surface subsidence,based on previous <br /> mining conducted within the permit area, site specific geologic conditions, seam <br /> thickness, and overburden depths,utilizing British National Coal Board(NCB) and U.S. <br /> Bureau of Mines modeling. The operator has predicted up to 7.7 feet of surface <br /> subsidence for longwall mining areas and up to 0.5 feet of subsidence for room and pillar <br /> mining area. Based on predicted horizontal tensile strains, surface cracks up to several <br /> inches wide are anticipated near zones of maximal subsidence, with the extent of cracking <br /> dependent on the nature of near surface geologic strata and surface soil cover. <br /> Measures employed to prevent subsidence material damage are addressed in Section <br /> IILA.7.g, of the application, and include a network of permanently supported mains and <br /> submains, barrier pillars, chain pillars, and unmined coal blocks in specific areas. The <br /> operator has committed to a program of visual monitoring to identify subsidence caused <br /> damage to surface structures, stock ponds, and major drainages, and has committed to <br /> repair hazardous tension cracks, subsidence features interrupting flow in Red Wash or <br /> Scullion Gulch, or damage to surface structures. <br /> Subsequent monitoring and observation have largely verified initial subsidence impact <br /> projections. Current and future monitoring includes twice a year visual inspection of <br /> mining area RP-1, and monitoring of Scullion Gulch, County Road 65, and stock pond <br /> reservoirs during periods of undermining. <br /> XVI. Concurrent Surface and Underground Mining <br /> No specific approvals are granted to the applicant under this section. <br /> xxxvi <br />