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NORTH DECLINE MINE DISCHARGE SYSTEM <br />ALTERNATIVE FLOW CALCULATIONS <br />The original calculations assume a bend at the junction of the drain pipe at two percent and the . <br />North Decline angled drill hole. The calculations should be checked as a single system from the <br />inlet to the outlet. The outlet should be above the top of the highway culvert to inhibit reverse flow <br />into the mine from the highway median. <br />Pipe length <br />Equivalent length of bend <br />Total length <br />Maximum Pool Elevation <br />Water Surface at Discharge Paint <br />Maximum Available Head <br />Required Discharge <br />Pipe Size <br />Pipe Inside Area <br />Velocity <br />Velocity Head <br />Entrance Loss -protruding - .8 VH <br />Exit Loss <br />Hazen Williams C <br />Friction Loss per 100 ft <br />Friction Loss <br />Total Loss <br />370 ft From Stover <br />20 ft From Stover <br />390 ft. <br />4760 ft From Stover <br />4755 ft Top of highway culvert <br />5 ft. <br />350 gpm From Stover <br />7.9 in <br />0.34 sf <br />2.29 fps <br />0.08 ft <br />0.07 ft <br />0.08 ft <br />100 <br />0.4548 ft <br />1.77 ft <br />1.92 ft Substantially similar to Stovefs talcs <br />Conclusion: The apparent capacity is high. The portion of the drain pipe to be installed at 2-percent <br />grade will not flow full. The flowing water will tend to drag the air above the water along the pipe <br />thereby creating a reduced, subatmospheric pressure in the pipe. This reduced pressure may cause <br />the water surface to contact the top of the pipe at intervals. A pulsating Flow capable of damaging <br />the system may result. To avoid this scenario S8G recommends that a vent be added to the high <br />point of the system to provide replacement air and establish atmospheric pressure. <br />