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Discharge from the portal is unlikely. The water quality of the flooded workings is <br />anticipated to be the same as that of the old Somerset Mine. After mine closure, the <br />proposed Sanborn Creek area is not expected to contribute additional dissolved <br />solids to the river. <br />The Elk Creek Mine, based on data from other mines in the vicinity, should not <br />experience problems with inflow or eventual discharge from the portal. Inflows <br />experienced in the vicinity include 115 gpm in the B seam at Oxbow, 15 gpm in the <br />C seam at Oxbow, and very little water at all in the D -seam in Bowie I and II, with <br />inflows of approximately 10 gpm. These inflow totals led to the conclusion that <br />there is little likelihood of eventual discharge from the portals. <br />In October 2004, the Division approved TR -47, which proposed to transfer mine <br />sump water from the D -Seam to the underlying abandoned C seam workings at a <br />rate of up to 3 million gallons per year via a surface borehole located in the upper <br />Elk Creek facilities. A description of the operation is found on Page 2.05 -96b. <br />A similar mine water transfer operation was proposed for the Hubbard Creek Fansite <br />facility, and approved under TR -51 in September 2005. With this operation, D- <br />Seam water may be transferred to the B -Seam workings. <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 regarding the sediment and drainage <br />control systems are found in the Sanborn Creek Mine Permit, pages 2.05 -34 through <br />38 and Map 2.05 -M4 (sheets 1 through 6). <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 areas. Other applicable effluent <br />limitations will also be met, as required by the NPDES permit. There is no evidence <br />of acid - 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 are the discharge from the <br />underground workings of the Elk Creek Tract, and drainage from waste piles located <br />at the site. The previously documented discharges from the Somerset Mine no <br />longer exist since mining and mine dewatering activities have ceased and the old <br />portals have been permanently sealed. Specific anticipated water quality impacts are <br />discussed within the Cumulative Hydrologic Impact Study for the North Fork of the <br />Gunnison River. It has been found that the Elk Creek Mine operation will not cause <br />significant salinity increase in the North Fork of the Gunnison River. <br />23 <br />