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CITY OF EVERETT STORMWATER MANAGEMENT MANUAL <br /> 2. Any areas that experience erosion shall be re-mulched and/or protected with a net or blanket. If <br /> the erosion problem is drainage related, then the problem shall be fixed and the eroded area re- <br /> mulched. <br /> Table 3.7 Mulch Standards and Guidelines <br /> Mulch Application <br /> Material Quality Standards Rates Remarks <br /> Straw Air-dried; free from 2"-3"thick; Cost-effective protection when applied with adequate <br /> undesirable seed 5 bales per thickness. Hand-application generally requires greater <br /> and coarse material. 1,000 sf or thickness than blown straw. The thickness of straw may be <br /> 2-3 tons per reduced by half when used in conjunction with seeding. In <br /> . acre. windy areas straw must be held in place by crimping, using a <br /> tackifier, or covering with netting. Blown straw always has to <br /> • be held in place with a tackifier as even light winds will blow it <br /> away. Straw should be used only if mulches with long-term <br /> � benefits are unavailable locally. It should also not be used <br /> � within the ordinary high-water elevation of surface waters <br /> (due to flotation). <br /> Hydro- No growth inhibiting Approx. 25-30 Shall be applied with hydromulcher. Shall not be used <br /> mulch factors. Ibs per 1,000 without seed and tackifier unless the application rate is at <br /> sf or 1,500— least doubled. Fibers longer than about 0.75 to 1-inch clog <br /> 2,000 Ibs per hydromulch equipment. Fibers should be kept to less than <br /> acre. 0.75 inch. <br /> Com- No visible water or 2"thick min.; More effective control can be obtained by increasing <br /> posted dust during approx. 100 thickness to 3 inches. Excellent mulch for protecting final <br /> Mulch and handling. tons per acre grades until landscaping because it can be directly seeded or <br /> Compost (approx. 800 tilled into soil as an amendment. Composted mulch has a <br /> (see note) Ibs per yard). coarser size gradation than compost. It is more stable and <br /> practical to use in wet areas and during rainy weather <br /> conditions. <br /> Chipped Average size shall 2" minimum This is a cost-effective way to dispose of debris from clearing <br /> Site be several inches. thickness. and grubbing, and it eliminates the problems associated with <br /> Vegetation Gradations from burning. Generally, it should not be used on slopes above <br /> fines to 6 inches in approx. 10 percent because of its tendency to be transported <br /> length for texture, by runoff. It is not recommended within 200 feet of surface <br /> variation, and waters. If seeding is expected shortly after mulch, the <br /> interlocking decomposition of the chipped vegetation may tie up nutrients <br /> properties. important to grass establishment. <br /> • Wood- No visible water or 2"thick; This material is often called "hog or hogged fuel." It is usable <br /> ' Based dust during approx. 100 as a material for Stabilized Construction Entrances (BMP <br /> Mulch (see handling. tons per acre C105) and as a mulch. Special caution is advised regarding <br /> � note) (approx. 800 the source and composition of wood-based mulches. <br /> - Ibs/cubic yd). <br /> Note: these mulches must be purchased from a supplier with a Solid Waste Handling Permit(or one exempt from <br /> solid waste regulations) <br /> 3.2.9 BMP C122: Nets and Blankets <br /> Purpose <br /> Erosion control nets and blankets are intended to prevent erosion and hold seed and mulch in place on <br /> steep slopes and in channels so that vegetation can become well established. In addition, some nets and <br /> blankets can be used to permanently reinforce turf to protect drainage ways during high flows. Nets <br /> (commonly called matting) are strands of material woven into an open, but lligh-tensile strength net(for <br /> Volume ll— Construction Stormwater Pollution Prevention <br /> 3-15 <br />