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The surface disturbance in Munger Canyon proposed in the initial five-yeac peeinit will <br />be comprised of the mine bench, the waste disposal pile and haul roads leading to the <br />portal area. These disturbances will affect approximately 35 acres. The surface <br />disturbance along and adjacent to East Salt Creek consists ofthe Central facilities area, <br />coal processing waste pile, conveyor System and interconnecting access road which will <br />increase the disturbed azea to 122 acres. <br />With respect: to surface water quality, a portion of the operation is required to be <br />contained within a sedimentation system. Runoff from the mine bench, central facilities <br />area and the two waste disposal piles will be routed through sediment ponds. These areas <br />present the greatest potential for affecting water quality because of the exposure of <br />subsurface materials and the high level of activity associated wits these areas. <br />Total suspended sediment concentrations will be minimized by passing water from <br />disturbed art:as through sediment ponds which are designed to remove and contain <br />suspended solids. Total dissolved solids concentrations will slightly increase as a result <br />of runoff from the disturbed areas. In all probability, the nutoff from most storm events <br />will not result in dischazge from the ponds and, therefore, will not affect the total <br />dissolved solids concentration in the receiving stream. <br />If a portion of the operation situated in Munger Canyon experienced a storm requiring <br />discharge from the ponds, the total dissolved solids concentration would probably be <br />diluted by water from undisturbed areas in the natural channel. The disturbed area (35 <br />acres) accourts for approximately seven-tenths of a percent of the drainage azea (5,085 <br />acres) of Munger Canyon. This relationship provides a rough estimate of the extent to <br />which dilution would occur. Furthermore, the disturbed azea in Munger Canyon <br />comprises fi~/e-hundredths of one percent of the total drainage area of East Salt Creek <br />above the confluence with Munger Canyon (67,288 acres). Further dilution would, <br />therefore, occur by the time the runoff from the disturbed area reaches the alluvial valley <br />floor. A similar relationship occurs for the portion of the operation situated along the <br />East Salt Creek drainage. The disturbed area (43.4 acres) accounts for approximately <br />six-hundredths of one percent of the total drainage area of East Salt Creek below the <br />confluence vrith Munger Canyon (72,373 acres). <br />Of the 35 acres to be disturbed by the portion of the operation situated in Munger <br />Canyon, approximately 8.4 acres is required to be controlled by sedimentation ponds. <br />The rest of t}ie disturbance will consist of the haul road. The amount of area essentially <br />removed frotn the drainage of Munger Canyon due to containment within the operation's <br />sedimentation system is approximately 8.4 acres. This accounts for less than two-tenths <br />of a percent of drainage area of Munger Canyon and less than two-hundredths of a <br />percent of thy. drainage area of East Salt Creek. Obviously, the reduction of such a small <br />amount of the drainage area will result in an insignificant reduction of surface flow <br />tributary to the alluvial valley floor. Additionally, all surface runoff retained by the <br />53 <br />