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at the first cut than when the operation proceeds updip. Inflows from units <br />underlying the Wadge are not expected, as mining methods should not cause <br />fracturing of the relatively impermeable underlying materials. Regional <br />aquifers located in or near the permit area include the Tow Creek <br />Sandstone, Trout Creek Sandstone and Twenty Mile Sandstone. <br />The Twenty Mile Sandstone lies stratigraphically above the Wadge coal (the <br />seam being mined) by about 525 feet. The Twenty Mile Sandstone which <br />has been eroded over much of the Seneca II-W Mine area, will not be <br />disturbed by mining operations, so its water quality and quantity will not be <br />affected. <br />The Tow Creek Sandstone lies more than 1300 feet below the Wadge coal. <br />Due to the thickness of the interburden between the Tow Creek and Wadge, <br />it is not likely that hydraulic pressures capable of affecting this aquifer will <br />develop. Therefore, mining activities are not expected to disturb this <br />regional aquifer. <br />About 200 feet below the Wadge coal lies the Trout Creek Sandstone. The <br />Trout Creek is thought to be an aquifer of regional significance, but is not <br />monitored at this site. The applicant completed a water supply well in the <br />Trout Creek from which they sustain an average pumping rate of 35 gallons <br />per minute. The relatively impermeable interburden between the Wadge <br />coal and the Trout Creek Sandstone (which includes the Wolf Creek coal) <br />and the stratigraphic distance between them will preclude impacts to the <br />Trout Creek sandstone from mining. <br />The Wolf Creek coal seam, which lies 150 to 170 feet below the Wadge coal <br />seam, is the first significant aquifer below the mined seam. This seam, <br />which is up to 12 feet thick, appears to be saturated in this area. Due to the <br />dip of the unit and the confining nature of the over and underburden, the <br />Wolf Creek has as much as 770 feet of artesian head in a well. It should be <br />noted that the amount of head is aerially variable as the aquifer conditions <br />change from water table (unconfined) near outcrops to confined conditions <br />at depth. <br />Due to mining methods and the thickness and type of interburden between <br />the Wolf Creek and Wadge, pit inflows from upward movement of the Wolf <br />Creek are not expected. If fracturing of the interburden and/or the Wolf <br />Creek coal, due to blasting or unloading of materials (overburden and <br />Wadge coal seam), were to occur, it is estimated that 80% of the Wolf <br />Creek head would be lost to friction, leaving a maximum total head of about <br />155 feet, which could potentially result in minor inflow. <br />The aquifer characteristics of the Wolf Creek (low transmissivity and <br />storativity values) indicate that very little water is available for upward <br />movement. Due to the distance between the Wadge and Wolf Creek, <br />26 <br />