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minus 3 inch coal into a truck for delivery. The plus 3 inch coal is currently sold as lump <br />• coal, but as production increases, a crusher may be installed to crush this excess lump <br />down to a minus 3 inch size. This crushed coal would then all be conveyed into trucks. <br />Since the run of mine product is sold, no coal reject is made. Surface disturbance is <br />minimum. Due to recent difficulty in stabilizing the immediate mine roof, Blue Ribbon <br />may be required to bring a small amount of the roof rock to the surface for storage. If <br />this requirement arises, the mine will present this topic at a later date. <br />(4) Ponds, Impoundments and Diversions <br />A soil loss comparison contained in Appendix C demonstrates that untreated drainage <br />from the reclaimed area will contribute fewer suspended solids to stream flow or runoff <br />outside the permit area as untreated drainage from the natural surrounding pre-mining <br />area. Therefore, sediment ponds are no longer required so they can be reclaimed. The <br />discussion below about the sediments ponds and drainage control is no longer <br />applicable to the reclaimed mine. <br />Sediment control on and around the surface disturbance area consists of diversions, <br />collection ditches and sediment ponds. The majority of unaffected surface drainage is <br />• diverted around the disturbed area. The disturbed area drainage is collected into ditches <br />and diverted to sediment ponds prior to discharge into Hubbard Creek. <br />Appendix C (revised 1/22/82) contains calculations performed by Ute Engineering for <br />runoff from the disturbed and undisturbed areas. The calculations are based upon sub <br />areas as shown on Exhibit H. Other assumptions include a 10 year 24 hour storm event <br />of 1.7", CN's of 77 for undisturbed areas and 89 for disturbed areas. The ditch and <br />culvert sizes to handle the runoff are calculated in Appendix C and shown on Exhibits <br />G, G' and H. The ditches and culverts to convey runoff from areas 2, 5 and 7 were <br />recalculated for the mine bench stabilization project in 1984-1985., For detail, see <br />"Sediment Control Comments and Calculations" Map B and Appendix 1-B of the Blue <br />Ribbon Technical Revision Request for Mine Bench Stabilization. <br />The Hubbard Creek crossing culvert was installed in 1980 and no calculation for sizing <br />is available. Calculations are shown on pages P-1 through P-8 in Appendix C for <br />Hubbard Creek. <br />These calculations indicate that the Hubbard Creek Culvert will pass the 10 year 24 <br />• hour storm event of 838 cfs but not the 20 year 24 hour event of <br />TR-15 <br />105 <br />09/08 <br />AP~Ra~Ea <br />/d~7~a8 <br />