931 BROADWAY TEUTSCH STUDENT HOUSING 2018-03-07

CITY OF EVERETT STORMWATER MANAGEMENT MANUAL treated solely by a barrier,rather than by a sediment pond, is when the area draining to the barrier is small. • Brush barriers should only be installed on contours. Design and/nstallation Specifications 1. Height 2 feet(minimum) to 5 feet(maximu�n). 2. Width 5 feet at base(minimum) to 15 feet (�naximum). 3. Filter fabric (geotextile) may be anchored over the brush berm to enhance the filtration ability of the barrier. Ten-ounce burlap is an adequate alternative to tilter fabric. _ 4. Chipped site vegetation, composted mulch, or wood-based mulch (hog fuel) can be used to construct brush barriers. 5. A 100 percent biodegradable installation can be constructed using ]0-ounce burlap held in place " by wooden stakes. Maintenance Standards 1. There shall be no signs of erosion or concentrated runoff under or around the barrier. lf concentrated flows are bypassing the barrier, it must be expanded or augmented by toed-in filter fabric. 2. The dimensions of the barrier must be maintained. 3.3.14 BMP C233: Silt Fence Purpose Use of a silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. See DCSS Drawing# 214. Conditions of Use • Silt fence may be used downslope of all disturbed areas. • Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to a sediment pond. The only circumstance in which overland flow can be treated solely : by a silt fence, rather than by a sediment pond, is when the area draining to the fence is 1 acre or less and flow rates are less than 0.5 cubic feet per second. " • Silt fences should not be constructed in streams or used in V-shaped ditches. They are not an adequate method of silt control for anything deeper than sheet or overland flow. Design and lnstal/ation Specifications 1. Draina�e area of 1 acre or less or in combination with sediment basin in a larger site. 2. Maximum slope steepness (normal [perpendicular] to fence line) 1:1. 3. Maximum sheet or overland flow path length to the fence of 100 feet. 4. No flows greater than 0.5 cubic feet per second shall be directed toward a silt fence. 5. The geotextile used shall meet the following standards. All geotextile properties listed below are minimum average roll values (i.e.,the test result for any sampled roll in a lot shall meet or exceed the values shown in Table 3.10). Volume 11— Construction Stormwater Pollution Prevention 3-54