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Blue Mountain Energy 4 Illustration 62 <br />included in these sections as an added measure to protect against localized erosion. Most of the <br />terraces feed into an existing rip rap channel except for structure 5 which feeds into structure 8, another <br />erodible channel. Structures 2 and 3 are the ditch along side the pile access haul road. They will need to <br />be lined with rip rap as specified in the 100-year calculations, but it could be years before the pile gets <br />high enough to require the access road. <br />Sedimentology <br />Sedimentology was modeled for the 10 Year storm. The sediment ponds reduce the settleable solids <br />concentration to well below the 0.5 ml/l. A summary of the sediment pond performance is included in <br />Table 1. <br />Table 1. Sediment Pond Performance <br /> <br />Peak Settleable <br />Concentration (ml/l) <br />Sediment Pond In Out <br />RP-5 195.85 0.09 <br />RP-4 188.80 0.00 <br />RP-2-3 177.23 0.03 <br /> <br /> <br />References <br />OSMRE. Guidelines for the Use of the Revised Universal Soil Loss Equation on Mined Lands, Construction <br />Sites, and Reclaimed Lands. Version 1.06. August 1998. <br />USDA NRCS Conservation Engineering Division. Technical Release 55 (TR-55). June 1986. <br />USDA NRCS. Web Soil Survey. https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm <br />NOAA National Weather Service. Precipitation Frequency Data Server. <br />https://hdsc.nws.noaa.gov/hdsc/pfds/ <br />Fletcher, B. P. and Grace, J. S., Jr. Practical Guidance for Estimating and Controlling Erosion at Culvert <br />Outlets. 1972. Corps of Engineers Research, Report H-72-5, Waterways Experiment Station, Vicksburg, <br />Mississippi. <br />