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Peabody <br />• <br />• <br />• <br />Twentymile Coal Company <br />RECEIVED <br />Mrs. Janet Binns MAR 0 2 2009 <br />Environmental Protection Specialist <br />Colorado Division of Minerals and Geology Division of naciamation, <br />1313 Sherman Street, Room 215 Mining and Safety <br />Denver, Colorado 80203 <br />(303) 866-4933 <br />29515 Routt County Road #27 <br />Oak Creek, CO 80467 <br />970.879.3800 <br />February 23, 2009 <br />RE: Twentymile Coal Company - Foidel Creek Mine (Permit No. C-82-056), Minor Revision <br />(MR09-236) for 6MN Nitrogen Injection and Meteorological Station Installation <br />Dear Mrs. Binns: <br />Twentymile Coal Company (TCC) requests CDRMS approval of a Minor Revision (MRO-236) to the <br />approved Permit, for installation of temporary skid-mounted nitrogen injection systems at the 6-Main <br />North (6MN) and 18-Right (18RT) ventilation shaft locations to address MSHA compliance requirements <br />relative to monitoring and control of mine atmosphere in sealed mine areas, and a new meteorological <br />station near the Mine Facilities Area, to address possible future air modeling needs. The proposed <br />facilities are shown on Map 24, Surface Facilities and Freshwater Systems, with details provided by <br />drawings in Exhibits 49A and 49C. <br />The nitrogen injection systems will be located on the existing, approved 6MN and 18RT pads, and each <br />will consist of a nitrogen generator, two air compressor's, a diesel generator, and a control building. The <br />purpose of the nitrogen injection system is to create and assure an inert, non-explosive atmosphere in the <br />sealed gob areas. It is anticipated that fixed pipelines within the existing boreholes at the 6MN and 18RT <br />locations will connect underground to one or more manifolded pipe systems running through the bleeder <br />entries to each of the sealed gob areas. Valved pipes, extending through the seals in each area, will <br />connect to the pipe system, allowing injection of nitrogen, as appropriate to meet MSHA compliance <br />requirements. At the surface wellhead (with appropriate grounding and lightning protection) the fixed <br />pipelines will connect to the skid-mounted nitrogen generatosr. Because all associated ancillary facilities <br />will be located within the existing disturbance areas, no modification of the existing drainage and <br />sediment control system or extension of the existing facilities pads will be necessary. <br />The meteorological station will consist of two small concrete pads (3 x 3 and 4 x 4 feet), one for a 30-foot <br />tower and one for a solar panel array; the metal tower with monitoring equipment, transceiver, and guy <br />wires; the solar panels; and a steel box for control and recording units. The station will be located <br />approximately 500 feet southeast of the Area 1 Pit, in a regraded spoils area on a 30 x 30 foot pad. The <br />station will be accessed by a 400 x 20 foot light-use road from the existing permitted overburden stockpile <br />area. Prior to any surface disturbance, Alternative Sediment Controls (ASC's - wattles and/or silt <br />fencing) will be installed down-gradient from the pad and along the road to control runoff and sediment. <br />Soil materials from the road and pad will be recovered and placed in Stockpile SF-3. The road will be <br />graveled to control erosion and sediment, and to facilitate all-season access. <br />G:\Environmental\REVISION\M1NOR-RV\MR09-236 6MN Nitrogen Inject and Met Sta\MR09-236 6MN Nitrogen Inject and <br />Met Sta TLRI.doc