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<br />February 27, 1997 ~- 963-2178 <br />debris) of leaves and sticks, grasses, and oak brush root system of the undisturbed natural <br />vegetation slopes was taken as being equivalent to a grass filter of the following description: <br />Manning's "n" = 0.01 (approximately the middle of the allowable range, <br />nearly equivalent to a dense stand of fescue); spacing = 0.2' (The <br />distance is taken as representative as the spacing between leaves, grass <br />sterns, and other debris of the ground cover.); height = 2" (a <br />representative depth of ground litter); stiffness = 2 (equivalent to a stand <br />of Bermudagrass, Retardance Class B/C); and an infiltration rate = 0.05 <br />(lowest of a hydrologic soil profile of "C"). <br />RESULTS <br />SedCAD+ demonstration computer printouts are attached. Refer to Maps 53B and 54B, and <br />Exhibits 66 and 69 for SAE Facility designations and locations. <br />The SedCAD+ demonstrations provide information on the Peak Settleable Concentrations <br />expected in effluent from the vegetative debris filters. The grass filters and resulting <br />settleable solid concentrations aze c~mmari~ed in the following table. <br />TABLE 5 <br />SILT FENCE/STRAW BALE FILTERS AND <br />PEAK SETTLEABLE CONCENTRATIONS <br />CONCLUSIONS <br />This SedCAD+ analysis review demonstrated that dischazges from all sites will meet the <br />effluent SSp standards of 0.5 m1/1 following a 10.year, 24-hour storm event. However, if <br />8161:~V5~'I]B~?I]8EM7. L7R Golder QSSOCiates <br />