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. BFMs and MBFMs provide good alternatives to blankets in most areas requir- <br /> ing vegetation establishment.Advantages over blankets include: <br /> . BFM and MBFMs do not require surface preparation. <br /> . Helicopters can assist in installing BFM and MBFMs in remote areas. <br /> . On slopes steeper than 2.5H:1V, blanket installers may require ropes <br /> and harnesses for safety. <br /> . Installing BFM and MBFMs can save at least$1,000 per acre com- <br /> pared to blankets. <br /> Maintenance Standards <br /> Reseed any seeded areas that fail to establish at least 80 percent cover(100 percent <br /> cover for areas that receive sheet or concentrated flows). If reseeding is ineffective, use <br /> an alternate method such as sodding, mulching, or nets/blankets. If winter weather pre- <br /> vents adequate grass 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 achieving <br /> adequate cover. Reseed and protect by mulch any eroded area. <br /> . Supply seeded areas with adequate moisture, but do not water to the extent that it <br /> causes runoff. <br /> Approved as Equivalent <br /> Ecology has approved products as able to meet the requirements of BMP C120: Tem- <br /> porary and Permanent Seeding. The products did not pass through the Technology <br /> Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to <br /> accept this product approved as equivalent, or may require additional testing prior to con- <br /> sideration for local use. The products are available for review on Ecology's website at <br /> http://www.ecy.wa.gov/programs/wq/stormwater/newtech/eq uivalent.html. <br /> BMP C121: Mulching <br /> Purpose <br /> Mulching soils provides immediate temporary protection from erosion. Mulch also <br /> enhances plant establishment by conserving moisture, holding fertilizer, seed, and top- <br /> soil in place, and moderating soil temperatures. There is an enormous variety of <br /> mulches that can be used. This section discusses only the most common types of mulch. <br /> Conditions of Use <br /> As a temporary cover measure, mulch should be used: <br /> 2014 Stormwater Management Manual for Western Washington <br /> Volume 11- Chapter 4 -Page 284 <br />