3900 BROADWAY BASE FILE 2016-01-01 MF Import

CITY OF EVERETT STORMWATER MANAGEMENT MANIIAL 1 ! treated solely by a batrier,tather than by a sediment pond,is when the area draining m the barrier is small. • B�ush batriers should only be installed on contours. Design and Installation SpeciRcations 1. Height 2 feet(minimum)l0 5 feet(maximum). 2. Wiath 5 feet at base(minimum)to I S feet(maximum). 3. Filter fabric(geotextile)may be anchored over the brush betrn to enhance the filtration ability of the bacrier. 'Cen-ounce burlap is an adequate altemetive to 6lter fabric. 4. Chipped site vegetation,composted mulch,or wood-based mulch(hog fuel)can be used to construct btvs6 bazticrs. 5. A l00 percent biodegradable installation can be constcucted using 10-ounce burlap held in place by wooden stakes. Maintenance Standards l. Thcro shall be no signs of erosion or concentrated runoff under or around the bacrier. If concentrated tlows aze bypassing the bartier,it must be expanded or augmented by toed-in f lter fabric. 2. The dimensions of the bamer must be maintained. 3.3.14 BMP C233: Silt Fence • ,� Purpose Use of a silt fence reduces the transpott of coarse sediment Gom a conshucuon site by providing a temporary p6ysical barrier to sediment and reduciog the runoff velocities of overland tlow. See DCSS Drawing#214. CondifJons of Use • Silt fence may be used downslope of all disturbcd azeas. • Silt fence is not intended to trcat concentrated flows,nor is il intended to treat substantial amounts of overland flow. My concentrated flows must be conveyed through the drainage system to a sediment pond. The only cirr,umstance in which ovedand tlow can be treated solely by a silt fence,rether than by a sediment pond,is when the area draining to the fence is I acre or Icss and flow rates are less than 0,5 cubic feet per second. • Silt fences should not bc conshuctcd in strcams or used in V-shapcd ditchcs. They arc not an adequate method of silt control for anything deeper than sheet or overland fiow. Design and Insfallation Specifications 1. Draioage arca of I acre or less or io combination with sediment basin in a larger site. 2. Maximum slopc steepness(nocmal [perpendicularJ to fencc line) I:l. 3. Maximutn shect or ovedand flow path length co the fence af l00 fcet. 4. No flows�cater than 0.5 cubic fcet per second shall bc d'vected towazd a silt fence. 5. The geotextile used s6a11 meet the following standazds. Nl geotextile properties listed below are minimum average mll values(i.e.,the test result for any sampled roll irt a lot shall meet or excced the values shown in Table 3.10). Volume 11—Construction Stormwater Pollution Prevention 3-54