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-19- Although underground mining occurs in areas adjacent to the alluvial valley floor, all surface disturbances are located more than a mile upstream from the alluvial valley floor, and would not affect agricultural activities on the alluvial valley floor. The alluvial valley floor would not be undermined by the proposed operations. 2. Pursuant to Rule 2.06.8(5)(a)(ii), the Division finds that the proposed surface coal mining operations would not materially damage the quantity and quality of water in surface and ground water systems that supply this alluvial valley floors or portions of alluvial valley floors. All of the surface flow from the permit area drains to the North Fork of the Gunnison. The two largest drainages are Lone Pine Gulch, to the west, and Sylvester Gulch, to the east. WECC has monitored both drainages. During the monitoring period, Lone Pine Gulch experienced ephemeral flow. The recorded yield of water from Sylvester Gulch was 208 acre-feet per year in 1978, and was less than 1% of the mean annual flow in the North Fork of the Gunnison River. In addition, mining during the permit term will be limited to the "C" Seam, which is separated from the surface by several hundred to over a thousand feet of bedrock throughout the permit and adjacent areas. Surface flow supplied to the alluvial valley floor along the North Fork comes primarily from areas upstream from the permit area and this flow is regulated by Paonia Reservoir. This reservoir is located approximately 6 miles upstream of the alluvial valley floor. Total surface disturbance is limited to 8 acres at the Bear No. 3 Mine and 19 acres at the Bear No. 1 and No. 2 facilities area. Drainage from the disturbed area is treated in sediment ponds and discharges from these ponds meets the effluent limitations of Ru]e 4.05. Ground water supplied from bedrock strata is minimal. No major aquifers have been identified in either the coal seam or the overburden. Springs in the area are associated with lenticular sandstones, local faulting and fracturing, and landslides. No springs or seeps have been identified in the area to be mined by Bear Coal Company. Surface operations will have an insignificant impact on the quantity of flow in the North Fork of the Gunnison. Mining operations require approximately 5.5 acre-feet of water per year, less than 0.03% of the mean annual flow in the North Fork of the Gunnison River. Surface disturbance in the alluvium adjacent to the river was limited to topsoil removal and foundation work. Surface facilities consist of office and shop buildings, a 10,000 ton open coal storage stockpile, access and haul roads, diversions and a sediment pond. All surface drainage from disturbed areas will be routed to the sedimentation pond where suspended sediments are allowed to settle out (see Map 10 of the Bear No. 3 application). There is a potential for slight increase in total dissolved solids (TDS) concentrations in the North Fork alluvial ground water as a result of percolation through coal stockpiles and the sediment pond. No evidence of an increase in TDS has been seen to date. The potential for this water quality degradation is considered insignificant for the following reasons: