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-zo- With respect to surface water quality, a portion of the operation is required to be contained within a sedimentation system. Runoff from the mine bench and the waste disposal piles will be routed through sediment ponds. These areas present the greatest potential for affecting water quality because of the exposure of subsurface materials and the high level of activity associated with these areas. Total suspended sediment concentrations will be minimized by passing water from disturbed areas through sediment ponds which are designed to remove and contain suspended solids. Total dissolved solids concentrations will slightly increase as a result of runoff from the disturbed areas. In all probability, the runoff from most storm events will not result in discharge from the pond and, there- fore, will not affect the total dissolved solids concentration in the receiving stream. If the operation experienced a storm requiring discharge from the ponds, the total dissolved solids concentration would probably be diluted by water from undisturbed areas in the natural channel. The disturbed area (35 acres) accounts for approximately seven-tenths of a percent of the drainage area (5,085 acres) of Munger Canyon. This relationship provides a rough estimate of the extent to which dilution would occur. Furthermore, the disturbed area in Munger Canyon comprises five-hundredths of one percent of the total drainage area of East Salt Creek above the confluence with Munger Canyon (67,288 acres). Further dilution would, therefore, occur by the time the runoff from the disturbed area reaches the alluvial valley floor. Of the 35 acres to be disturbed by the operation, approximately 8.4 acres is required to be controlled by sedimentation ponds. The rest of the disturbance will cronsist of the haul road. The amount of area essentially removed from the drainage of Munger Canyon due to containment within the operation's sedimentation system is approximately 8.4 acres. This accounts for less than two-tenths of a percent of drainage area of Munger Canyon and less than two- hundredths of a percent of the drainage area of East Salt Creek. Obviously, the reduction of such a small amount of the drainage area will result in an insignificant reduction of surface flow tributary to the alluvial valley floor. Additionally, all surface runoff retained by the structures will eventually be returned to the system. No ground water was encountered within coal seams and their associated roof and floor strata during exploratory drilling in the mine plan area. The appli- cant, therefore, does not anticipate any significant mine inflow which would require discharging of mine water. Munger Canyon is an ephemeral stream. Therefore, its flow is not sustained by ground water during low flow periods through springs and seeps. If the mine were to experience mine inflows, the ground water depleted from the hydrologic system would not be significant. Therefore, the depletion of ground water will not impact the quantity of water tributary to the alluvial valley floor.