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differences between the design and the as-built, the ditch was stable and no erosional problems <br />were noted. <br />PM-4B: The channel is designed as a trapezoidal ditch, with a bottom width of 3 feet and an <br />overall depth of 0.6 feet and a lining of vegetation. The as-built channel has a bottom width of 6 <br />feet and an overall depth of approximately 18 inches. The channel flows at an approximate slope <br />of 26%, as compared to an average design slope of 22%. The ditch was stable and no erosional <br />problems were noted. <br />Channel PM-4D: This channel is a TRM lined V ditch. The TRM was dislodged from the <br />channel and there was deep gullying from midpoint of the channel to the bottom end. The <br />gullying is down to the bedrock below the channel. A plan to repair this channel will be <br />necessary. The instability of this channel indicates that surface water control has not been <br />established; this drainage channel will be excluded from the Phase I release. <br />Surge Ponds: Seneca Coal Company has built numerous surge ponds in the permanent, post- <br />mining drainage channels at the Seneca II-W Mine to help slow runoff and protect the <br />permanent, post-mining channels and sediment ponds. These surge ponds are permitted as <br />permanent structures that will remain in place to help control runoff from their associated <br />watersheds. There was some erosion at the inlet side of each of the ponds and erosion at the <br />outfall side of the ponds (the exception being the outfall of the surge pond below the confluence <br />of post-mining channels PM-3/PM-3A, which exhibited little to no erosion). Close monitoring <br />of these surge ponds and maintenance work as necessary will be needed to ensure the ponds and <br />their associated post-mining channels remain stable. The Division requested that the location of <br />these surge ponds be depicted on the as-built exhibit for the post-mining drainage channels for <br />SL-3 (Exhibit D). SCC submitted the revised profiles (Exhibits B and D of the SL-3 <br />Application) on March 11, 2011. <br />Stock Tanks - There are three stock tanks in the Seneca II-W Mine South Extension Area; T-25, <br />T-26 and T-27. As with the surge ponds discussed above, there was erosion at both the inlet and <br />outfall sides of these stock tanks. SCC was repairing some of the erosion problems on the stock <br />tanks in the PM-2 drainage area (T-26 and T-27) at the time of the inspection. These three <br />stocktanks were not included in the SL-3 bond request, and so have not been evaluated for bond <br />release. <br />In summary all channels met the minimum design criteria, and many of the channels were <br />overbuilt with regard to size (bottom width and side slopes), and riprap requirements. With the <br />exception of PM-2D and PM-4D, the channels are stabilizing. Annual maintenance will be <br />necessary to promote further stabilization in certain locations; the Division will retain the <br />appropriate performance bond for ongoing maintenance of the channels in the proposed bond <br />release area. <br />Light Use Roads <br />Page 15 of 22