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~• Waste water from the coal wash plant was recycled back into the coal washing facility after fines settled out in upper and lower settling ponds. This water recycling system increased the total dissolved solids in the water through exposure of the water to fines and through evaporation. The ponds that were used in this water recycling system are unlined and are located on or are hydrologically adjacent to the North Thompson Creek alluvium. Thus, these ponds posed a potential for the degradation of the alluvial water quality directly and, indirectly, the surface water quality of North Thompson Creek. Alluvial monitoring well D-lA below the refuse pile has a water chemistry markedly different from that in North Thompson Creek. The high levels of both total dissolved solids, between 3498 and 3982 mg/l, and sulfates, between 1900 and 2700 mg/l, indicate the refuse pile sediment pond and unlined settling ponds may in part have impacted the quality of alluvial ground water and quality of surface water. The applicant states that this poor water quality is due to alluvial ground water flow over the Mancos Shale. However, alluvial water quality analyses of the Coal Creek alluvial ground water show water qualities favorably comparing to the surface water qualities in spite of the fact that there are greater exposures of Mancos Shale in the Coal Creek Drainage Basin. The water used at the loadout site was pumped from wells completed in the Roaring fork alluvium. The withdrawal of this ground water was small and covered under a plan of augmentation which minimized impact to the quantity of alluvial ground water. There has been no evidence of any adverse impacts to the ground water quality at the loadout site. 2. Surface Water One of the potential impacts associated with most mining operations is increased sediment loads to receiving streams. This would be caused by surface disturbance which increases soil loss. Unnatural sediment loads to receiving streams could be detrimental in the following ways: a. Fish reproduction, growth rate, and life span could be reduced. b. Stream temperature could be increased. c. Stream channel capacity could be reduced. d. Drainage structures and downstream irrigation systems could be clogged. e. Alluvial water tables could be raised. f. Floodplains could be altered. g. Sediment may carry toxic substances that could change water quality. To minimize the potential impacts of sediment loads at this mine, the operator constructed a sediment control system. This system treats all mine discharges and surface disturbed runoff -!6-