Laserfiche WebLink
February 27, 1997 -4- 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 />stems, 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 are summarized 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 discharges from all sites will meet the <br />effluent SSp standards of 0.5 ml /l following a 10 -year, 24 -hour storm event. However, if <br />8161A96U17812178EM2.LTR Golder Associates <br />�OIl:f1. <br />,,p L; <br />::...... ::::.:::::::::::.:: <br />............................ tt :..:....::::::.:.. <br />............................... y............................................................ <br />:..:.::::::::.:..:....:........ .................::.:::£::::::: <br />Topsoil Storage <br />toe of slope of the pile <br />400 <br />200 <br />0.00 <br />Pile #1 <br />Topsoil Storage Pile #2 <br />toe of slope of the pile <br />450 <br />50 <br />0.00 <br />plus Subsoil Storage Pile <br />Topsoil Storage <br />toe of slope of the pile <br />300 <br />100 <br />0.17 <br />Pile #3 <br />Topsoil Storage <br />toe of slope of the pile <br />400 <br />500 <br />0.00 <br />Pile #4 <br />Cut Slope above <br />east and downgradient of <br />200 <br />100 <br />0.00 <br />Substation, and <br />the cut slope <br />Substation <br />CONCLUSIONS <br />This SedCAD + analysis review demonstrated that discharges from all sites will meet the <br />effluent SSp standards of 0.5 ml /l following a 10 -year, 24 -hour storm event. However, if <br />8161A96U17812178EM2.LTR Golder Associates <br />