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<br />C. Suspended Solids Demonstration <br /> <br />In accordance with Section III.A.7.a. of the Division’s 1995 “Guideline Regarding Selected <br />Coal Mine Bond Release Issues”, SCC submitted pond discharge sample data for Pond 008, <br />which receives discharge from the proposed release area. The pond outfall data indicates <br />that total suspended solids (TSS) contributions do not exceed the limits set forth by the <br />Colorado Department of Public Health and Environment. <br />The sediment pond receiving runoff from the proposed release area (Pond 008) has been <br />approved as a permanent pond; the operator demonstrated that the quantity and quality of <br />impounded water is appropriate for its intended use, water rights will not be adversely <br />affected, safe access to the impounded water has been provided, and the pond is appropriate <br />for the post-mining land use. <br />In addition to the pond effluent sample data submitted by SCC, the Division requested <br />annual sediment level data from Seneca Coal Company (Table 2) for Pond 008. The data <br />show that sediment levels in the pond have stabilized since revegetation activities began in <br />2003. The pond has never required cleaning and has never been dredged. <br /> <br />Table 2 – Sediment Data Provided by Seneca Coal Company <br /> <br />Sediment Trends <br /> <br />(ac-ft gained/lost by year) <br /> <br /> <br />Pond ID 2005 2006 2008 2010 <br /> <br />008 0.0 -0.1 -0.1 +-0.2 <br /> <br />The Division also independently completed a Revised Universal Soil Loss Equation <br />(RUSLE) calculation comparing the reclaimed areas to the adjacent unmined areas. The <br />Division’s calculation was based on data in the permit application package for climate, soil <br />types and control/practice factors; slope measurements from the existing topography maps <br />submitted annually by SCC; and vegetation monitoring data from the SL-5 application for <br />the Phase II bond release and Extended Reference areas. Several slopes in the reclamation <br />area were individually modeled and then averaged and compared to a weighted average of <br />the extended reference areas. The calculations, presented in Table 3, indicate that sediment <br />delivery from the mined areas is approximately equal to that of the adjacent unmined areas. <br />Table 3 – Division’s RUSLE Calculations <br /> <br />Area* A R K LS C P <br />SIIPM-13A <br /> <br />0.06502 30 0.24 2.15 0.003 .35 <br />V-Ditch 4 <br /> <br />0.06653 30 0.24 2.20 0.003 .35 <br />Upper Ditch 1 <br /> <br />0.06713 30 0.24 2.22 0.003 .35 <br />