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2. Surface Water <br />• The WSC Hawk's Nest Mine and processing facilities are located within <br />the North Fork drainage, a tributary to the Gunnison River. The North Fork <br />subdrainage ranges in elevation from 5,500 to 12,000 feet and drains a total <br />of 1,253 square miles, producing an average annual discharge of 469,300 acre <br />feet, or 648 cubic feet per second (cfs) (USGS 1974). The average annual flow <br />rate of the river at the location of the mine is 315,100 acre feet, or 435 cfs. <br />Peak flows of the North Fork Gunnison River occur in May as a result of melting <br />snowpacks. The North Fork Gunnison River generally flows in a westerly direc- <br />tion into the Gunnison River and, subsequently, into the Colorado River. <br />A discussion of the water quality of the North Fork Gunnison River can be <br />found in the Regional Analysis Final ES (BLM 1979). In general, the North Fork <br />is slightly alkaline with conductivity increasing with stream length, primarily <br />• due to agricultural return flows. Nutrient levels (ammonia, nitrite, nitrate, <br />and phosphate) are not excessively high. With the exception of occasional high <br />iron levels, there is no evidence of a serious dissolved metals content. In <br />fact, the Colorado Department of Health classifies the North Fork Gunnison <br />River as a B-1 quality water system. <br />There are six intermittent streams on the permit area of which no records <br />of flow are in existence. During snow melt, runoff from these streams con- <br />tributes to the flow of the North Fork Gunnison River. Recent water samples <br />taken in Anthracite Creek above and below Crystal Meadows, in the North Fork <br />above and below the mining operations, and in other locations are included in <br />Appendix C. <br />• The water used in the WSC Hawk's Nest Mine operations comes from the North <br />Fork Gunnison and the industrial-use well (4-26-023918F) on the WSC lease area <br />37 <br />