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activities. The loading facilities and office area are adjacent to Oak Creek, but above the 100-year, 24-hour floodplain. Trout Creek forms the western boundary of the permit area. The ephemeral streams which drain the permit area flow west or northwest into Trout Creek. Sediment ponds are located at the base of these tributaries above their confluence with Trout Creek. The disturbed area is 4190 acres, or 8 percent of the 54 square mile Trout Creek drainage basin. The average annual runoff in Trout Creek is 37,500 acre-feet. The mine area is estimated to yield approximately 730 acre-feet of runoff annually, or about 2 percent of the total annual stream flow of Trout Creek above the mine. Annual mean minimum discharge is estimated at 10 cubic feet per second (cfs). Only a small area of mine-related disturbance drains into Oak Creek. Although no mining occurs within this watershed, the loadout, conveyor, access road, and office are situated within the Oak Creek Basin. Of the total 140 acres of basin area within the permit boundary, only about 24 acres are disturbed by the mine. This area is a small fraction of the total drainage area of 27.4 square miles upstream of the mine on Oak Creek. Average annual yield is estimated at 7,900 acre-feet. Runoff from the permit area is estimated at 25 ac-ft, or 0.3 percent of the total annual stream flow of Oak Creek above the mine. The estimated mean minimum flow is 5 cfs. Seasonal runoff hydrographs for both streams show peak discharge occurring in April, May, and June as a result of snowmelt runoff. Low flows in both streams begin in the late summer and extend through the winter months until the onset of spring runoff. A large portion of the permit area has been previously mined, replacing consolidated overburden with spoil materials. Deep percolation of precipitation through the spoils has created a water table aquifer which abuts against the now buried highwall or box cut near the foot of the previously mined slope. Numerous springs have formed as a result. These springs emanate from the relatively steep slope which exists above the alluvium on the east side of Trout Creek. Water quality conditions upstream of the mine indicate that dissolved iron, manganese and other trace metals all have occasionally exceeded receiving stream standards. Baseline data indicate minor changes in water quality occur between upstream and downstream stations on both Trout and Oak Creeks. This is probably due to the impacts of past mining activities. The baseline quality of the water in Oak Creek is generally poorer than that in Trout Creek above the permit area due to more extensive mining that has occurred in the Oak Creek drainage during the past century. Land Use Current and historic land use in the vicinity of the operation has been coal mining, livestock grazing and wildlife habitat. Historically, coal has been extracted from the mine area by both surface strip and underground methods. na me 9 ermn evision o.