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-26= <br />Now that mining is completed in the east pit and Barren Ridge areas, ground <br />water inflows to'the backfilled pits will continue until an equilibrium water <br />table is established. As ground water levels in the affected strata rise, the <br />rate of inflow will slowly decrease. During this period, water will be <br />depleted from the Stollsteimer Creek surface water system. The depletion of <br />Stollsteimer Creek flows will be minor, 1 to 3 gpm on the Barren Ridge side <br />and 10 gpm or less from the east side pit at the beginning of the pit inflow <br />period. <br />Surface and ground water quality has been slightly degraded as the water was <br />exposed to the affected strata in the pit. Ground water quality in the lower <br />Fruitland Formation, Pictured Cliffs Sandstone and the alluvium of <br />Stollsteimer Creek will be affected only after an equilibrium water table is <br />established in the backfilled pits, auger holes, and the affected strata. <br />Since the area of saturated spoil is small and since the strata of the Lower <br />Fruitland Formation have low permeabilities, only a small quantity of degraded <br />water from the backfill will recharge these aquifers. The degraded water <br />which does recharge these aquifers will be diluted by ground water in the <br />aquifers, or will discharge to the Stollsteimer Creek stream/alluvial system <br />within a short distance of the downgradient auger holes. The anticipated <br />increase in total dissolved solids (TDS) in the Stollsteimer Creek alluvium <br />has been estimated to be 0.6Y. <br />In Deep Creek Canyon, mining will remove the "A" and "B" coal seams of the <br />lower Fruitland Formation. <br />Near the Barren Ridge area, aquifer testing was done in 1982 and 1983 to <br />determine transmissivity, storativity, and hydraulic conductivity values for <br />the lower Fruitland Formation. An aquifer test was also performed on the <br />Stollsteimer Creek alluvium in 1982 to determine transmissivity. The <br />Fruitland values may be used to describe aquifer characteristics in the Deep <br />Canyon area, while the alluvial data is not directly applicable. <br />Step drawdown and continuous discharge tests of the lower Fruitland show that <br />the Fruitland sandstones, shales, and coal transmit water in a semi-confined <br />state, and that the actual movement of water within the aquifer zones is <br />somewhat limited. Due to the proximity of Deep Creek Canyon to Barren Ridge, <br />and assuming that lithology does not significantly differ from place to place <br />the aquifer charateristics described at Barren Ridge probably hold true for <br />the lower Fruitland at Deep Creek Canyon. <br />Alluvial aquifer tests at the Martinez Strip area indicate that this material <br />is capable of laterally transporting significant amounts of water. It is <br />assumed that these alluvial aquifers are an important source of recharge to <br />the underlying Fruitland aquifer. It is also assumed that the <br />alluvial/colluvial material in Deep Creek Canyon has about the same hydraulic <br />characteristics (porosity, permeability) as the Stollsteimer alluvium. <br />However, due to (1) the proximity of Stollsteimer Creek, and its potential to <br />recharge the Stollsteimer alluvium; (2) the steep topography of Deep Creek <br />Canyon; and, (3) the variable thickness of the Deep Creek Canyon <br />