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• Road 711 b. Mountain Coal Company owns water rights for these water sources. <br />Minimum water levels will be maintained in the stock ponds to insure water is left for <br />stock and wildlife. <br />DRILLING ACTIVITIES <br />Drilling activities for the proposed gob vent / de-gas boreholes will include mobilizing <br />drill equipment to the sites and drilling and setting 40 feet of 16 inch surface casing into <br />bedrock. The holes will be rotary drilled with a 15 inch hole to within I ~0 feet of the B- <br />Seam, then cased with 9 5/8 ID steel casing, then an 8 5/8 inch hole will be drilled to <br />within 50 feet of the B-Seam in the "relaxed zone" (refer to the Typical Surface Vertical <br />Degas Well figure). It is proposed that multiple holes will be drilled from each of the <br />pads to minimize surface disturbance. <br />DE-GAS INSTALLATION <br />Passive de-gassing of the longwall panels would be accomplished by extending a non- <br />metal stack to the surface casing, attaching a lightning arrestor to it and venting to the <br />ambient atmosphere. Active de-gassing would require a trailer or skid mounted gas <br />exhauster, flame arrestor, valves, and non-metal stack with lightning arrestor that would <br />exhaust the gases to the ambient atmosphere (see the Gob Ventilation Borehole General <br />Surface Arrangement, attached). The trailer would be totally enclosed with fencing and <br />• locked to protect and prevent persons from tampering with the equipment. The equipment <br />would need to be approved and inspected by the Mine Safety and Health Administration <br />(MSHA) prior to installation. <br />MONITORING <br />Initially, MSHA may require monitoring and inspection of the active de-gas installation <br />twice daily after installation. It is anticipated the frequency of monitoring would decrease <br />to a weekly monitoring and inspection of the installation. <br />PROPOSED DRILL HOLE PLUGGING METHODS <br />The hole plugging methods described in 43 CFR II 3484.1 (a) or Colorado Division of <br />Minerals and Geology (CDMG) Rules and Regulations at 4.07.3, will be used for all <br />holes. It is anticipated that each hole will be plugged with cement from bottom to 50 feet <br />above the uppermost thick coal seam and from 50 feet below to 50 feet above any <br />aquifers encountered in the hole. The remainder of the hole will be filled with an <br />approved completion mud, gel, cuttings, or cement to within 5 Feet of the surface. A 5- <br />foot cement surface plug will be set, and an appropriately labeled monument mazker will <br />be cemented into the surface plug. Surface casing will be cut off at or below the level of <br />the soil surface. <br />• <br />