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Drainage from disturbed areas can contribute additional suspended solids to offsite stream systems; however, the above-referenced sediment control systems will effectively control sediment yield to offsite areas. Other applicable effluent limitations will also be met, as required by the NPDES permit. There is no evidence of acid-forming or toxic-producing materials. The operation will result in slightly increased total dissolved solids levels in the North Fork of the Gunnison River. The sources are the discharge from the underground workings of the Sanborn Creek Tracts, and drainage from waste piles located at the site. The previously documented discharges from the Somerset Fline no longer exist since mining and mine dewatering activities have ceased and the old portals have been permanently sealed. Specific anticipated water quality impacts are discussed within the Cumulative Hydrologic Impact Study for the North Fork of the Gunnison River. It has been found that the Somerset Mine operation, including the Sanborn Creek addition, will not cause significant salinity increase in the North Fork of the Gunnison Rive r. The mine will not adversely impact flooding processes or streamflows in the North Fork of the Gunnison River. Mining operations are not expected to decrease flows in any of the ephemeral or intermittent drainages to be undermined. The operation will not adversely impact downstream water users. The operator will use about 35,000 gallons per day for underground and above-ground dust suppression. This water will be drawn from an existing surface water right of 7.8 cfs, on the North Fork of the Gunnison River. More detailed information is available in the CHIS for the North Fork of the Gunnison River. IV. Topsoil The Division has determined that selected overburden materials may be used for, or as a supplement to, topsoil. The resulting soil should be equal to or better than tiie available fill material. This determination will be based on physical and chemical analyses and field-site trials approved by the Division (4.06.2(4)(a)). Somerset Mining Company has agreed to remove and/or bury coal and coaly material on the pre-law Elk Creek yard area. Since topsoil is not available, the resulting surface material will be tested to determine if it is suitable as plant growth medium. If it is not, it will be covered by at least six inches of suitable plant growth medium or topsoil salvaged from development of the present coal mine waste pile area or the Sanborn Creek facilities areas. The areas stripped of topsoil for emplacement of the Sanborn Creek facilities will be regraded following mining, tested and treated with topsoil in a similar fashion. All stockpiled topsoil will be used in reclamation. None will be left stockpiled upon final reclamation. The topsoil stockpiled at the upper Hubbard Creek area will be used to partially cover pre-law waste piles that exist at the lower Hubbard Creek area. The upper Hubbard Creek bench will be retained as an approved USFS parking lot. _l g_