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<br />2) Barrier pillars - To ensure that no caving or pillar crushing of the mains occur due to adjacent <br />mining, a 300 to 400-foot homogeneous barrier pillar borders all mains and submains, and 200 <br />to 300-foot barrier pillars are left in place separating adjacent continuous miner pillar sections. <br />3) Chain pillars -Each longwall will be bordered along the length of the panel by two rows of <br />chain pillars. Chain pillars are sized to minimize subsidence and provide a safe mining <br />environment. The size of chain pillars is determined primarily by seam depth and seam <br />thickness and will be adjusted as these parameters change. The ends of the longwalls <br />will be separated from the mains by one 200-foot barrier pillar. <br />4) Abandoned coal -There are several areas within each coal seam where specific coal areas will <br />be abandoned due to geological and physical mining problems. <br />III.A.7.h Damage Mitigation. BME plans to carefully observe the areas above the active mining and <br />immediately fill any tension cracks that could present a potential danger to livestock and wildlife. <br />Expected subsidence will not change the usefulness of the land that now consists of both steep and <br />gently rolling topography. <br />BME will recompense in full any loss of livestock caused by subsidence effects to any surface owner or <br />• any rancher leasing surface areas from the government. Should the number of tension cracks above a <br />particular longwall present a safety hazard, BME will fence off the area above the active mining until <br />completion of the panel. Any stock ponds or reservoirs damaged by subsidence will be repaired as <br />necessary. <br />Rio Blanes County Road 65 crosses diagonally over an area above the mine where subsidence is <br />expected. The subsidence prediction study indicates that the maximum horizontal tensile strain of <br />about 6600 micro-strain over the D-Seam mine and 11,300 micro-strain over the B-Seam mine will <br />occur where County Road 65 crosses above LW-10 and LW-2B. This amount of strain could disturb <br />the road. BME plans to conduct an ongoing monitoring and maintenance program in addition to <br />posting speed limit and subsidence-hazard signs whenever coal is extracted under the county road. <br />County Road 65 will be monitored daily while mining below it and during the active subsidence period. <br />Any damage will be repaired; including any cracks that could create a safety hazard or delay traffic. <br />BME contends that there will be no damage to the building structures in the permit area, and the only <br />use of the surface above the mine is for access and limited sheep grazing. Therefore, any subsidence <br />that may occur will not lessen the present or foreseeable use of the land. <br />• Midterm Review (8/2002) III-18 <br />