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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 will be conducted during "B" seam extraction <br />beneath the road. The stock pond reservoirs referenced above could potentially be <br />impacted by tension cracks due to longwall subsidence (Raven Park and Halandras <br />Reservoir No. 1). Lincoln Reservoir is located over a room and pillar mining area. Pillar <br />dimensions and extraction ratio consistent with main entries will be employed beneath the <br />reservoir to prevent subsidence. The stock ponds will be visually monitored during <br />undermining, and repaired as necessary (see discussion in the Probable Hydrologic <br />Consequences narrative of this document). The powerline is owned by BME, and the <br />mine is the only customer served by the powerline. Power structures within areas of <br />active subsidence will be monitored periodically by the operator, and repaired if <br />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 />III.A.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 />XVL Concurrent Surface and Underground Mining <br />No specific approvals are granted to the applicant under this section. <br />37 <br />