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S <br /> • <br /> CITY OF EVERETT STORMWATER MANAGEMENT MANUAL <br /> a <br /> c. Minimum volume of excavation 3.5 cubic yards <br /> • d. Shape basin to fit site with longest dimension oriented toward the longest inflow area <br /> e. Install provisions for draining to prevent standing water problems <br /> f. Clear the area of all debris <br /> ID g. Grade the approach to the inlet uniformly <br /> • h. Drill weep holes into the side of the inlet <br /> - i. Protect weep holes with screen wire and washed aggregate <br /> j. Seal weep holes when removing structure and stabilizing area <br /> k. It may be necessary to build a temporary dike to the down slope side of the structure to <br /> • prevent bypass flow. <br /> i 2. Block and Gravel Filter—A bather formed around the storm drain inlet with standard concrete <br /> • blocks and gravel. See also DCSS Drawing#209. <br /> a. Height 1 to 2 feet above inlet <br /> b. Recess the first row 2 inches into the ground for stability <br /> 411 <br /> • c. Support subsequent courses by placing a 2 x 4 through the block opening <br /> d. Do not use mortar <br /> e. Lay some blocks in the bottom row on their side for dewatering the pool <br /> • f. Place hardware cloth or comparable wire mesh with one-half-inch openings over all <br /> block openings <br /> g. Place gravel just below the top of blocks on slopes of 2:1 or flatter <br /> • h. An alternative design is a gravel donut <br /> i. Inlet slope of 3:1 <br /> • <br /> j. Outlet slope of 2:1 <br /> • k. 1-foot wide level stone area between the structure and the inlet <br /> • 1. Inlet slope stones 3 inches in diameter or larger <br /> • m. Outlet slope use gravel one-half to three-fourths inches at a minimum thickness of <br /> I foot. <br /> • 3. Gravel and Wire Mesh Filter—A gravel barrier placed over the top of the inlet. This structure <br /> does not provide an overflow. See DCSS Drawing#210. <br /> ID a. Hardware cloth or comparable wire mesh with one-half-inch openings <br /> • b. Coarse aggregate <br /> • c. Height 1 foot or more, 18 inches wider than inlet on all sides <br /> d. Place wire mesh over the drop inlet so that the wire extends a minimum of 1 foot beyond <br /> • each side of the inlet structure <br /> e. If more than one strip of mesh is necessary, overlap the strips <br /> 411 f. Place coarse aggregate over the wire mesh <br /> • <br /> S <br /> w Volume ll—Construction Stormwater Pollution Prevention <br /> 3-50 <br /> a <br />