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CITY OF EVERETT STORMWATER MANAGEMENT MANUAL <br />g. The depth of the gravel should be at least 12 inches over the entire inlet opening and <br />extend at least 18 inches on all sides. <br />4. Curb Inlet Protection with Wooden Weir — Barrier formed around a curb inlet with a wooden <br />frame and gravel. <br />a. Wire mesh with one -half -inch openings <br />b. Extra strength filter cloth <br />c. Construct a frame <br />d. Attach the wire and filter fabric to the frame <br />e. Pile coarse washed aggregate against wire/fabric <br />f. Place weight on frame anchors. <br />5. Block and Gravel Curb Inlet Protection — Barrier formed around an inlet with concrete blocks <br />and gravel. See DCSS Drawing # 211. <br />a. Wire mesh with one -half -inch openings. <br />b. Place two concrete blocks on their sides abutting the curb at either side of the inlet <br />opening. These are spacer blocks. <br />c. Place a 2 x 4 stud through the outer holes of each spacer block to align the front blocks. <br />d. Place blocks on their sides across the front of the inlet and abutting the spacer blocks. <br />e. Place wire mesh over the outside vertical face. <br />f. Pile coarse aggregate against the wire to the top of the barrier. <br />6. Inlet Fabric Fence Filter — DCSS Drawing # 212 provides an illustration of the use of filter fabric <br />as an inlet protection option. <br />Maintenance Standards <br />1. Catch basin filters should be inspected frequently, especially after storm events. If the insert <br />becomes clogged, it should be cleaned or replaced. <br />2. For systems using stone filters: If the stone filter becomes clogged with sediment, the stones <br />must be pulled away from the inlet and cleaned or replaced. Since cleaning of gravel at a <br />construction site may be difficult, an alternative approach would be to use the clogged stone as <br />fill and put fresh stone around the inlet. <br />3. Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly <br />over the surrounding land area or stockpile and stabilize as appropriate. <br />3.3.12 BMP C230: Straw Bale Barrier <br />Purpose <br />1. To decrease the velocity of sheet flows and intercept and detain small amounts of sediment from <br />disturbed areas of limited extent, preventing sediment from leaving the site. See Figure 3.3. <br />2. Below disturbed areas subject to sheet and rill erosion. <br />3. Straw bales are among the most used and least effective BMPs. The best use of a straw bale is <br />hand spread on the site. <br />Volume 11 — Construction Stormwater Pollution Prevention <br />3-51 <br />