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northeast. The location of the gateroads are shown on Figure I6C, 9 and 10 Right Gateroad Extensions. Right of <br />• entry into the coal contained in these gateroads will be provided to [he Division prior to mining. <br />Driving of the gateroads will not result in any additional surface disturbance. The gateroads arc driven by a <br />continuous miner, with each gateroad entry approximately 20 feet wide and 9 fee[ high. The coal mined fpm the <br />gateroads will be processed through Twentymile's existing surface /tipple facility. Water used for dust <br />suppression encountered during mining will be discharged through Twentymile's existing facilities (either site I I S <br />or 109). The indicated permit boundary has been squared up to make i[ easier to describe, however, the actual <br />mining will occur within an area of less than 20 acres. <br />EMD Seismic Lines <br />Twentymile is planning ro conduct a limited seismic investigation in an attempt to obtain additional information <br />on the fault encountered in [he 9 and 10 Right gateroads. TCC has tried to use this tool in [he past to evaluate <br />faulting in the EMD, but the investigations have not proven to be successful. However, this program will utilize a <br />different technology than used in the pas[ and TCC is optimistic the data obtained will be useful in evaluating <br />the fault. This program will use dte classic approach of drilling holes, setting off charges, and geophones and <br />instruments for recording the data. W i[h [he advances in computer technology, TCC is optimistic better resolution <br />of the signal can he obtained and this will be used to define the fault. <br />The seismic program will entail establishing four lines as shown on Figure 16D, 1995 Seismic Lines, East Mining <br />District. Geophones will be laid out over each of the lines to record the data. Drill holes will be established on <br />100 foot centers over the length of the line. The geophones may extend 1,000 feet past the ends of the shot line. <br />The drill holes will be approximately 20 fee[ deep (this will be [he maximum depth) and will have a nominal <br />• diameter of 4 inches. The cuttings from the drill holes will be used as stemming over [he I - 2 pound charge that <br />will be placed in the bottom of the hole. The holes will be drilled with a rubber tired drill rig. It is not planned to <br />construct any roads to aid in the drilling of the holes. The rig is sufficiently mobile to eliminate the need for road <br />building activities. Upon completion of [he program the geophones and cable will be recovered. Based upon the <br />limited depth of the holes and the fact that the cuttings will be used to backfill the holes prior to shooting, no <br />further reclamation work is planned. <br />Phase Il Scismic Exploration <br />Twentymile is proposing to conduct additional seismic investigations in the EMD. This seismic program will <br />entail the establishment of four lines as shown on Figure 16[, 1996 Seismic Lines and Mine Water Return Line, <br />East Mining District. <br />Each seismic line will consist of a series of shot holes drilled on 100 foot centers. Shot holes will be drilled with <br />air and will have a 4-inch diameter with depths ranging from I S to 19 feet. Each hole will be loaded with a I.5 <br />pound dynoseis charge, set with a hold down plug, then back filled with cuttings. Approximately 340 to 360 shot <br />holes will be drilled along the 6 I/2 to 6 3/4 miles of seismic line. The geophones will be placed on 25 foot center~s~,t,., <br />and cables will be extended approximately 500 feet beyond the ends of the shot line. Holes will he offset weak <br />power lines are located immediately overhead. All shot holes within 100 feet of overhead power lines will have <br />additional surface shot wire anchors to prevent the wires t}om flying up and fowling the power lines. <br />Surface disturbance should be minimal. The holes will be drilled with a medium sized rubber tired drill rig using <br />mi onboard compressor to blow cuttings. No roads +vill be constructed to aid in the drilling operations as the rig is <br />• sufficiently mobile to eliminate the need for road building activities. Several small gates will be cut in fence lines <br />to allow full access. All fence damage will be repaired immediately upon completion of the seismic lines. Upon <br />completion of the investigation, the geophones and cable will he recovered. Based upon the limited depth of the <br />MR 97-154 2.05-5 Revised 9/9197 <br />