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Due to mining methods and the thickness and type of interburden between the Wolf <br />Creek and Wadge, pit inflows from upward movement of the Wolf Creek are not <br />expected. If fracturing of the interburden and/or the Wolf Creek coal, due to <br />blasting or unloading of materials (overburden and Wadge coal seam), were to <br />occur, it is estimated that 80% of the Wolf Creek head would be lost to friction, <br />leaving a maximum total head of about 155 feet, which could potentially result in <br />minor inflow. <br />The aquifer characteristics of the Wolf Creek (low transmissivity and storativity <br />values) indicate that very little water is available for upward movement. Due to the <br />distance between the Wadge and Wolf Creek, fracturing of the Wolf Creek due to <br />mining is improbable. Inflow from the Wolf Creek coal seam into the open or <br />reclaimed pits is not expected to occur. <br />The Wadge coal and its overburden, which may locally contain the Lennox coal <br />seam, generally stores and transmits water. While mining, water will be induced <br />to flow into active and reclaimed pits. This water will flow mainly from the <br />Wadge coal, but also from the overburden. The operator estimated the following <br />values for aquifer characteristics in the Wadge Coal and Wadge Overburden: <br />* Hydraulic conductivity of overburden = .Ol ft./day <br />* Hydraulic conductivity of coal = 0.02 ft./day (north pit), .Ol ft. day (south <br />pit) <br />* storativity = 10' for both aquifers <br />* Transmissivity = 4.5 ft. z/day for overburden <br />* Transmissivity = 0.12 ft. Z/day for coal <br />* Hydraulic gradient of overburden = .165 (north pit), .085 (south pit) <br />* Hydraulic gradient of coal = .15 (north pit), .11 (south pit) <br />The preceding estimated values for hydraulic conductivity and transmissivity are <br />somewhat lower than most values reported for these aquifers by mines in the area. <br />Tables 5 and 6 in Robson and Stewart's (1990) report indicates ranges in hydraulic <br />conductivity from 0.1 to 0.6 ft./day for the overburden aquifer and two values of <br />.02 and .4 ft./day for the Wadge Coal. <br />The Division's PHC findings are based on the possibility of greater inflows than <br />those predicted by the applicant. The Williams Fork Formation overburden which <br />locally contains the Lennox Coal Seam, may contain perched aquifers as well as <br />acting as a limited aquifer system near the Wadge coal. The overburden does not <br />contain or transport significant amounts of water in this area. <br />Seneca II-W Findings Document 40 November 17, 2004 <br />Permit Revision No. 4 <br />