Laserfiche WebLink
Generally, products come in 40-50 pound bags and include all <br />necessary ingredients except for seed and fertilizer. <br />• BFMs and MBFMs provide good alternatives to blankets in most <br />areas requiring vegetation establishment. Advantages over <br />blankets include: <br />• BFM and MBFMs do not require surface preparation. <br />• Helicopters can assist in installing BFM and MBFMs in remote <br />areas. <br />• On slopes steeper than 2.51-1:1 V, blanket installers may require <br />ropes and harnesses for safety. <br />• Installing BFM and MBFMs can save at least $1,000 per acre <br />compared to blankets. <br />Maintenance <br />Reseed any seeded areas that fail to establish at least 80 percent cover <br />Standards <br />(100 percent cover for areas that receive sheet or concentrated flows). If <br />reseeding is ineffective, use an alternate method such as sodding, <br />mulching, or nets/blankets. If winter weather prevents adequate grass <br />growth, this time limit may be relaxed at the discretion of the local <br />authority when sensitive areas would otherwise be protected. <br />• Reseed and protect by mulch any areas that experience erosion after <br />achieving adequate cover. Reseed and protect by mulch any eroded <br />area. <br />• Supply seeded areas with adequate moisture, but do not water to the <br />extent that it causes runoff. <br />Approved as <br />Ecology has approved products as able to meet the requirements of BMP <br />Equivalent <br />C 120. The products did not pass through the Technology Assessment <br />Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to <br />accept this product approved as equivalent, or may require additional testing <br />prior to consideration for local use. The products are available for review on <br />Ecology's website at <br />littp:// www. eev.wa. Gov/proQrams/wq/stomiwater/newtech/equivalent.html . <br />BMP C121: Mulching <br />Purpose <br />Mulching soils provides immediate temporary protection from erosion. <br />Mulch also enhances plant establishment by conserving moisture, holding <br />fertilizer, seed, and topsoil in place, and moderating soil temperatures. <br />There is an enormous variety of mulches that can be used. This section <br />discusses only the most common types of mulch. <br />Conditions of Use <br />As a temporary cover measure, mulch should be used: <br />• For less than 30 days on disturbed areas that require cover. <br />• At all times for seeded areas, especially during the wet season and <br />during the hot summer months. <br />Volume II — Construction Stormwater Pollution Prevention - December 2014 <br />4-19 <br />