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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 />during low flow periods through springs and seeps. If the mine were to experience mine <br />inflows, the ground water depleted from the hydrologic system would not be significant. <br />Therefore, the depletion of ground water will not impact the quantity of water tributary to the <br />alluvial valley floor. <br />The Division has sufficient information to determine the absence of alluvial valley floors in <br />Stove and Buniger Canyons. Sideslopes in the canyons are excessively steep (16 to 50%) <br />and are deeply incised. The potential for extensive deposits of unconsolidated alluvium is <br />minimal. Further, because these drainages encompass less drainage area than that of Munger <br />Canyon, it is likely that there is insufficient surface water runoff to sustain agricultural <br />activities. The fact that both streams are ephemeral indicates a low potential for subirrigation <br />by springs or seeps. Inspection of 7.5 minute topographic maps also indicates that there is no <br />irrigation along any stream courses in these drainages. <br />The water quality in Stove Canyon and Buniger Canyon will not be effected by mining since <br />there are no surface disturbances planned in these drainages. The quantity of water in these <br />drainages may be affected to a limited extent if surface waters are diverted into the mine <br />workings through natural or mining-induced fractures. Slopes of the natural surface in the <br />affected drainages range from 2v:1 h to 6v:1 h. On such high angle slopes, rainfall incidental <br />to the surface would have a greater tendency to flow over the surface than to infiltrate into <br />any mine workings. <br />The area of Stove and Buniger Canyons which would potentially be affected by subsidence <br />over mine workings for this permit term is approximately 185 acres. The Big Salt Wash <br />drainage basin encompasses 31,448 acres above the confluence with Stove Canyon. <br />42