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DocuSign Envelope ID: F52521E7-10C1-43F9-B62F-C1E599A5D572 Attachment C - NCDEQ Erosion Control Blanket Specs <br /> Practice Standards and Specifications <br /> 6.17 <br /> ROLLED EROSION CONTROL PRODUCTS <br /> RECP <br /> Definition Rolled erosion control products are manufactured or fabricated into rolls <br /> designed to reduce soil erosion and assist in the growth, establishment <br /> and protection of vegetation. Examples of RECP's are blankets, nets, and <br /> matting. <br /> Purpose Erosion control mats and blankets are intended to protect soil and hold seed and <br /> mulch in place on slopes and in channels so that vegetation can become well <br /> established. Turf reinforcement mats can be used to permanently reinforce <br /> grass in drainage ways during high flows. Nets are made of high tensile <br /> material woven into an open net which overlays mulch materials. Blankets <br /> are made of interlocking fibers, typically held together by a biodegradable <br /> or photodegradable netting(for example, excelsior or straw blankets). They <br /> generally have lower tensile strength than nets, but cover the ground more <br /> completely. Coir(coconut fiber)fabric comes as both nets and blankets. <br /> Conditions Where Rolled Erosion Control Products (RECP's) should be used to aid permanent <br /> vegetated stabilization of slopes 2:1 or greater and with more than 10 feet of <br /> Practice Applies vertical relief RECP's should also be used when mulch cannot be adequately <br /> tacked and where immediate ground cover is required to prevent erosion <br /> damage. <br /> RECP's should be used to aid in permanent stabilization of vegetated channels <br /> when runoff velocity will exceed 2 ft/sec on bare earth during the 2-year rainfall <br /> event that produces peak runoff. The product selected must have a permissible <br /> shear stress that exceeds the shear stress of the design runoff event. <br /> Planning • Good ground contact is critical to the effectiveness of these products. If <br /> Considerations good ground contact is not achieved, runoff can concentrate under the <br /> product,resulting in significant erosion. <br /> • Nets must be used in conjunction with mulch. Excelsior, woven straw <br /> blankets and coir(coconut fiber)blankets may be installed without mulch. <br /> There are many other types of erosion control nets and blankets on the <br /> market that may be appropriate in certain circumstances. In general,most <br /> nets(e.g.jute matting)require mulch in order to prevent erosion because <br /> they have a fairly open structure. Blankets typically do not require mulch <br /> because they usually provide complete protection of the surface. <br /> • Most netting used with blankets is photodegradable,meaning they break <br /> down under sunlight(not UV stabilized). However,this process can take <br /> months or years even under bright sun. Once vegetation is established, <br /> sunlight does not reach the mesh. It is not uncommon to find non- <br /> degraded netting still in place several years after the installation. This can <br /> be a problem if maintenance requires the use of mowers or ditch cleaning <br /> equipment. In addition, birds and small animals can become trapped in <br /> the netting. <br /> Rev.6/06 6.17.1 <br />