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Total suspended sediment concentrations will be minimized by passing water from disturbed <br />areas through sediment ponds which are designed to remove and contain suspended solids. <br />Total dissolved solids concentrations will slightly increase as a result of runoff from the <br />disturbed areas. In all probability, the runoff from most storm events will not result in <br />discharge from the ponds and, therefore, will not affect the total dissolved solids <br />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 diluted <br />by water from undisturbed areas in the natural channel. The disturbed area (35 acres) <br />accounts for approximately seven - tenths of a percent of the drainage area (5,085 acres) of <br />Munger Canyon. This relationship provides a rough estimate of the extent to which dilution <br />would occur. Furthermore, the disturbed area in Munger Canyon comprises five - hundredths <br />of one percent of the total drainage area of East Salt Creek above the confluence with <br />Munger Canyon (67,288 acres). Further dilution would, therefore, occur by the time the <br />runoff from the disturbed area reaches the alluvial valley floor. A similar relationship occurs <br />for the portion of the operation situated along the East Salt Creek drainage. The disturbed <br />area (43.4 acres) accounts for approximately six - hundredths of one percent of the total <br />drainage area of East Salt Creek below the confluence with Munger Canyon (72,373 acres). <br />Of the 35 acres to be disturbed by the portion of the operation situated in Munger Canyon, <br />approximately 8.4 acres is required to be controlled by sedimentation ponds or small area <br />exemption sedimentation controls. The rest of the disturbance will consist of the haul road. <br />The amount of area essentially removed from the drainage of Munger Canyon due to <br />containment within the operation's sedimentation system is approximately 8.4 acres. This <br />accounts for less than two - tenths of a percent of drainage area of Munger Canyon and less <br />than two - hundredths of a percent of the drainage area of East Salt Creek. Obviously, the <br />reduction of such a small amount of the drainage area will result in an insignificant reduction <br />of surface flow tributary to the alluvial valley floor. Additionally, all surface runoff retained <br />by the structures will eventually be returned to the system. Runoff from the portion of the <br />mining operation situated along East Salt Creek (87 acres) will also be contained in <br />sedimentation ponds, with the exception of the haul road which connects the central facilities <br />area with the coal processing waste pile. The amount of area essentially removed from the <br />drainage of East Salt Creek due to containment within the sedimentation system is <br />approximately 73.2 acres. This accounts for less than six - hundredths of one percent of the <br />drainage area of East Salt Creek below the confluence with Munger Canyon. This will result <br />in an insignificant reduction of surface flow to the alluvial valley floor. As with the sediment <br />ponds situated in Munger Canyon, all surface runoff retained by the structures will eventually <br />be returned to the system. <br />No ground water was encountered within coal seams and their associated roof and floor strata <br />during exploratory drilling in the mine plan area. The applicant, therefore, does not <br />anticipate any significant mine inflow which would require discharging of mine water. <br />Munger Canyon is an ephemeral stream. Therefore, its flow is not sustained by ground water <br />37 <br />