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structures will eventually be returned to the system. Runoff from the portion of the <br />mining operation situated along East Salt Creek (37 acres) will also be contained in <br />sedimentation ponds, with the exception of the haul road which connects the central <br />facilities azea with the coal processing waste pile. The amount of azea essentially <br />removed from the drainage of East Salt Creek due to containment within the <br />sedimentation system is approximately 73.2 acres. This accounts for less than <br />six-hundredths of one percent of the drainage azea of East Salt Creek below the <br />confluence with Ntunger Canyon. This will result in an insignificant reduction of surface <br />flow to the alluvial valley floor. As with the sediment ponds situated in Munger Canyon, <br />all surface runoff retained by the structures will eventually be returned to the system. <br />No ground water was encountered within coal seams and their associated roof and floor <br />strata during exploratory drilling in the mine plan azea. The applicant, therefore, does not <br />anticipate any significant mine inflow which would require dischazging of mine water. <br />Munger Canyon is an ephemeral stream. Therefore, its flow is not sustained by ground <br />water during low flow periods through springs and seeps. If the mine were to experience <br />mine inflows, the ground water depleted from the hydrologic system would not be <br />significant. Therefore, the depletion of ground water will not impact the quantity of <br />water tributary to the alluvial valley floor. <br />The Division has sufficient information to determine the absence of alluvial valley floors <br />in Stove and Buniger Canyons. Sideslopes in the canyons aze excessively steep (16 to <br />50%) and aze deeply incised. The potential for extensive deposits of unconsolidated <br />alluvium is minimal. Further, because these drainages encompass less drainage azea than <br />that of Munger Canyon, it is likely that there is insufficient surface water runoff to sustain <br />agricultural activities. The fact that both streams aze ephemeral indicates a low potential <br />for subirrigation by springs or seeps. Inspection of 7.5 minute topographic maps also <br />indicates that there is no imgation along any stream courses in these drainages. <br />The water quality in Stove Canyon and Buniger Canyon will not be affected by mining <br />since there aze no surface disturbances planned in these drainages. The quantity of water <br />in these drainages may be affected to a limited extent if surface waters aze diverted into <br />the mine workings through natural ormining-induced fractures. Slopes of the natural <br />surface in the affected drainages range from 2v:lh to 6v:lh. On such high angle slopes, <br />rainfall incidental to the surface would have a greater tendency to flow over the surface <br />than to infiltrate into any mine workings. <br />The azea of Stove and Buniger Canyons which would potentially be affected by <br />subsidence over mine workings for this permit term is approximately 185 acres. The Big <br />Salt Wash drainage basin encompasses 31,448 acres above the confluence with Stove <br />Canyon. Approximately 0.6% of the drainage area of Big Salt Wash could be affected by <br />thz operation in this worst-case scenario. This fact indicates that there is very little <br />sa <br />