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pcf, 8 to 10 plasticity index;, unconfirmed compressive strength <br />between 2000 and 6000 psf, and internal angle of friction between <br />5 and 15 degrees. <br />The Portal area ground support has been accomplished by using steel <br />arch tunnel supports having an approximate radius of 10 feet and <br />heavy-duty plat liners as necessary to maintain the entry. Ends of <br />the portals are equipped with the wire screens and doors providing <br />sufficient security and necessary egress from the mine. Tunnel No. <br />1 (intake tunnel) }ias approximately 10 arches installed through the <br />colluvial material, to self-su)~porting bedrock. Approximately 30 <br />arches were installed in Tunnel No. 2. <br />Small pads (approximately 0.2 acres or less) have been created as <br />a natural elongation of the drifts. The existing mountain slope is <br />from 15 to 25 degrees. The actual slope of the pads does not <br />exceed 30 to 35 degrees. The total volume of tl~e soil and other <br />sandy materials used per entry is about 5000 cubic yards. An <br />additional 5000 yd s' per entry will be used to further extend the • <br />existing pads and widen the access roads when tunnel excavation <br />continues (refer to Section 9.3.6.3). At the time of construction, <br />drainage diversions were prepared to divert flow away from the mine <br />entry. Baseline ground water studies have indicated that these <br />entries will not produce water, however, any water produced will be <br />captured and used in the hydraulic circuit. Prior to construction <br />of the aforementioned escapeway and/or raises, NCIG commits to <br />submitting detailed plans for these openings to CMLRD for their <br />review and approval. <br />A few operational advantages that hydraulic mining has over most <br />other mining methods are: <br />o In steeply pitching, thick and often faulted coal seams, <br />coal recovery is normally greater from a specific reserve <br />using hydraulic mining methods than with other, more well <br />NCIG - Coal Ridge #1 4-18 ABC/1145/910509 • <br />