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(d) In the abandoned Hawk's Nest Mine several drill holes were drilled from <br /> the active mine into lower seams. It is believed that these holes are not <br /> sealed and could provide a conduit for water to flow into the Sanborn <br /> Creek mine; however, as reported in the PHC, there was no evidence of <br /> flooding of the mine at the time of this renewal. <br /> Mine inflow, except that used in the mining process, will be treated and <br /> discharged to the North Fork. The discharge will meet NPDES standards, but <br /> it is expected that the discharge will have an elevated TDS for which there are <br /> no discharge standards. From recent water quality analyses, TDS values of <br /> 3,200 mg/l for the discharge can be expected. During the emergency mine <br /> water discharge of the Sanborn Creek Mine in 1999, water quality analyses of <br /> the discharge water showed TDS ranging from a low of 2,668 mg/l to a high of <br /> 4,785 mg/l. <br /> Post-mining impacts are expected to be minimal. The Sanborn Creek mine is <br /> expected to slowly flood to the level of the river, which is below the elevation <br /> of the portal. Discharge from the portal is unlikely. The water quality of the <br /> flooded workings is anticipated to be the same as that of the old Somerset <br /> Mine. After mine closure, the proposed Sanborn Creek area is not expected to <br /> contribute additional dissolved 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. <br /> Inflows experienced in the vicinity include 115 gpm in the B seam at Oxbow, <br /> 15 gpm in the C seam at Oxbow, and very little water at all in the D-seam in <br /> Bowie I and II, with inflows of approximately 10 gpm. These inflow totals led <br /> to the conclusion that there is little likelihood of eventual discharge from the <br /> portals. <br /> In October 2004, the Division approved TR-47, which proposed to transfer <br /> mine sump water from the D-Seam to the underlying abandoned C seam <br /> workings at a rate of up to 3 million gallons per year via a surface borehole <br /> located in the upper Elk Creek facilities. A description of the operation is <br /> found on Page 2.05-96b of the PAP. <br /> A similar mine water transfer operation was proposed for the Hubbard Creek <br /> Fan-site facility, and approved under TR-51 in September 2005. With this <br /> operation, D-Seam water may be transferred to the B-Seam workings. <br /> 2. Effects on Surface Water <br /> The areas of surface disturbance at the Somerset Mine are protected by <br /> sediment control systems including diversion and containment ditches, <br /> sediment ponds, and other alternate sediment control features such as rock, <br /> vegetation, and straw filters. All point source discharges are regulated under <br /> 28 <br />