Laserfiche WebLink
products are summarized in Table 7-12-2. The designs assume a mixed grass community 11 - <br />24" tall, which corresponds to a "B" retardance class, and results in a higher surface water <br />elevation. <br />The postmine channels at Seneca II Mine lined with T12Ms will b'e either three (3) or ten (10) <br />feet wide. The minimum channel designs for the TRM lined channels also are summarized on <br />the Channel Design Schedule table at the front of Appendix B. SEDCAD4 demonstrations are <br />presented in Appendix B. <br />T1tM installation will be in accordance with recommendations developed by the Erosion <br />Control Technical Council (ECTC, 2006) or the individual manufacturer's recommendations. <br />General installation steps are as follows: <br />1. Prepare a stable and firm soil surface free of large rocks and other obstructions. <br />Apply appropriate seed mixture. <br />2. Install TRMs after application of seed, mulches (if applicable) and other soil <br />amendments, unless soil in-filling is required. If soil in-filling is needed, install TRM, <br />apply seed and other amendments and brush or rake topsoil into TRM matrix. <br />3. Anchor top of blanket at end of channel section using trench and/or staples/stakes. <br />4. Unroll center blanket in direct of water flow on bottom of channel. Securely fasten <br />blanket to soil surface with stables/stakes in accordance with manufacturer's staple <br />pattern guide. If available, use colored dot pattern corresponding to the <br />manufacturer's recommended staple pattern. If applicable, overlap adjacent blankets <br />and staple. <br />5. Anchor full-length margin of blankets at top of side slopes with a row of staples/stakes. <br />Backfill soil material over final 12-inches of blanket margin and compact. <br />2.2.4 Post Mine Channel PM-8 Design Demonstration <br />Background: During the spring 2004 rill and gully survey, two large gullies were identified north of <br />Pond 008. SCC believes a rapid snowmelt directly up-gradient of the eroded area resulted in a <br />large flow of water which then caused the formation of fhe gullies. In addition, SCC believes that <br />temporary diversion channels constructed to divert water away from previously fenced vegetation <br />plots in the area also served to concentrate the flow of water and contributed to the creation of <br />the gullies. <br />• The gullies were repaired in late-spring 2004 by filling and roughening the gully areas and, <br />constructing a meandering flow path along the length of the gully areas down to Channel SIIPM-8. <br />The Division inspected the area during summer 2004 and informed SCC to either submit a <br />channel design or demonstrate that the meandering channel would stabilize the slope. SCC <br />TR-41 7-12-9 Revised 04/07 <br />