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gpm .) These inflow totals lead to the conclusion that there is little liklihood of <br />eventual dischazge from the portals. <br />Effects on Surface Water <br />The areas of surface disturbance at the Somerset Mine are protected by sediment <br />control systems including diversion and containment ditches, sediment ponds, and <br />other alternate sediment control features such as rock, vegetation and straw filters. <br />All point source discharges are regulated under the National Pollution Discharge <br />Elimination System (NPDES). Specific details regazding the sediment and drainage <br />control systems aze found in the Sanbom Creek Mine Permit, pages 2.05-34 through <br />38 and Map 2.05-M4 (sheets 1 through 4). <br />Drainage from disturbed areas can contribute additional suspended solids to offsite <br />stream systems; however, the above-referenced sediment control systems will <br />effectively control sediment yield to offsite azeas. Other applicable effluent <br />limitations will also be met, as required by the NPDES permit. There is no evidence <br />ofacid-forming or toxic-producing materials. <br />The operation will result in slightly increased total dissolved solids levels in the <br />North Fork of the Gunnison River. The sources aze the dischazge from the <br />underground workings of the Sanborn Creek Tracts, and drainage from waste piles <br />located at the site. The previously documented dischazges from the Somerset Mine <br />no longer exist since mining and mine dewatering activities have ceased and the old <br />portals have been permanently sealed. Specific anticipated water quality impacts aze <br />discussed within the Cumulative Hydrologic Impact Study for the North Fork of the <br />Gunnison River. It has been found that the Sanborn Creek Mine operation will not <br />cause significant salinity increase in the North Fork of the Gunnison River. <br />The mine will not adversely impact flooding processes or streamflows in the North <br />Fork of.the Gunnison River. Mining operations aze not expected to decrease flows <br />in any of the ephemeral or intermittent drainages to be undermined. The operation <br />will not adversely impact downstream water users. <br />The operator will use about 35,000 gallons per day for underground and <br />above-ground dust suppression. This water will be drawn from an existing surface <br />water right of 1.8 cfs, on the North Fork of the Gunnison River. More detailed <br />information is available in the CHIS for the North Fork of the Gunnison River. <br />IV. To soil <br />The Division has determined that selected overburden materials may be used for, or <br />as a supplement to, topsoil. The resulting soil should be equal to or better than the <br />available fill material. This determination will be based on physical and chemical <br />23 <br />