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not affect the total dissolved solids concentration in the receiving <br />stream. <br />If a portion of the operation situated in Munger Canyon experienced a <br />storm requiring discharge from the ponds, the total dissolved solids <br />concentration would probably be diluted by water from undisturbed areas <br />in the natural channel. The disturbed area (35 acres) accounts for <br />approximately seven-tenths of a percent of the drainage area (5,085 <br />acres) of Munger Canyon. This relationship provides a rough estimate <br />of the extent to which dilution would occur. Furthermore, the <br />disturbed area in Munger Canyon comprises five-hundredths of one <br />percent of the total drainage area of East Salt Creek above the <br />confluence with Munger Canyon (67,288 acres). Further dilution would, <br />therefore, occur by the time the runoff from the disturbed area reaches <br />the alluvial valley floor. A similar relationship occurs for the <br />portion of the operation situated along the East Salt Creek drainage. <br />The disturbed area (43.4 acres) accounts for approximately <br />six-hundredths of one percent of the total drainage area of East Salt <br />Creek below the confluence with Munger Canyon (72,373 acres). <br />Of the 35 acres to be disturbed by the portion of the operation <br />situated in Munger Canyon, approximately 8.4 acres is required to be <br />controlled by sedimentation ponds. The rest of the disturbance will <br />consist of the haul road. The amount of area essentially removed from <br />the drainage of Munger Canyon due to containment within the operation's <br />sedimentation system is approximately 8.4 acres. This accounts for <br />less than two-tenths of a percent of drainage area of Munger Canyon and <br />less than two-hundredths of a percent of the drainage area of East Salt <br />Creek. Obviously, the reduction of such a small amount of the drainage <br />area will result in an insignificant reduction of surface flow <br />tributary to the alluvial valley floor. Additionally, all surface <br />runoff retained by the structures will eventually be returned to the <br />system. Runoff from the portion of the mining operation situated along <br />East Salt Creek (87 acres) will also be contained in sedimentation <br />ponds, with the exception of the haul road which connects the central <br />facilities area with the coal processing waste pile. The amount of <br />area essentially removed from the drainage of East Salt Creek due to <br />containment within the sedimentation system is approximately 73.2 <br />acres. This accounts for less than six-hundredths of one percent of <br />the drainage area of East Salt Creek below the confluence with Munger <br />Canyon. This will result in an insignificant reduction of surface flow <br />to the alluvial valley floor. As with the sediment ponds situated in <br />Munger Canyon, all surface runoff retained by the structures will <br />eventually be returned to the system. <br />No ground water was encountered within coal seams and their associated <br />roof and floor strata during exploratory drilling in the mine plan <br />area. The applicant, therefore, does not anticipate any significant <br />mine inflow which would require discharging of mine water. Munger <br />Canyon is an ephemeral stream. Therefore, its flow is not sustained by <br />ground water during low flow periods through springs and seeps. If the <br />mine were to experience mine inflows, the ground water depleted from <br />the hydrologic system would not be significant. Therefore, the <br />depletion of ground water will not impact the quantity of water <br />tributary to the alluvial valley floor. <br />-46- <br />