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basin, including the downstream reaches of the perennial streams of Foidel Creek, Middle Creek, and Trout <br />Creek to the confluence with the Yampa River at Milner. The proposed general area includes the Twentymile <br />• Park ground water basin and the watersheds of Fish Creek, Foidel Creek, Middle Creek, and Trout Creek to the <br />confluence with the Yampa River at Milner. <br />The general information provided previously can be applied to the Eastern Mining District. This area is located <br />within the surface and ground water basins described above. Map 4, Proposed Hydrologic Area Boundaries, <br />presents the area covered in this permit application. <br />The ground water inflow into the mine during the proposed longwall operation in the Eastern Mining District <br />was calculated with the application of an analytical method (Maximov, 1975). Results of these calculations are <br />presented in Exhibit 9A, Ground Water Inflow Into Mine, Eastern Mining District, Table 1 and Table 2. These <br />Maximov (1975) and developed for the calculation of ground water inflow into horizontal sections of an <br />underground mine was used for mine inflow calculation: <br />q= KMs(n /at) <br />Where: q is water inflow per a longitudinal section of an underground mine (m3 /day) <br />K is hydraulic conductivity (m /day) <br />M is hydrostatic head (m) <br />s is drawdown <br />a is coefficient of piezoconductivity (m2 /day) <br />a = T/S where T is transmissivity (m2 /day) and S is storativity <br />t is time of dewatering days <br />The total inflow per ( longwall panel) section of the mine or level is then calculated from: <br />• Q =qx 1 <br />Where: 1 is length of dewatered section (m) <br />The total horizontal inflow per (longwall panel) section of the mine or level was calculated using hydraulic <br />conductivity ranging from 0.034 to 0.098 ft/day. The geometry of the mined area and time of dewatering are <br />based on mining plans. The analytical equation presented above was input into a simple spreadsheet computer <br />program (LOTUS 123) on an IBM computer. The results of the inflow calculations for the Eastern Mining <br />District are summarized and presented in Tables 3 and 4 of Exhibit 9A. The average inflow in one panel could <br />range from 65 to 230 gpm and the total inflow in the Eastern Mining District could range from 110 to 601 gpm. <br />The geology of the Eastern Mining District is similar to the previously permitted areas. A syncline axis, <br />oriented northwest - southeast is located in the central section of the mined area. The southeastern edge of the <br />proposed mining is defined by a split in the Wadge Coal Seam. Additional exploration boreholes will be drilled <br />in this area to better define the coal seam composition. <br />The Eastern Mining District area sedimentary strata are not disturbed by any significant faults. The structural <br />and lithologic characteristics of the permit area are depicted on Geologic Cross Sections B -B' (east -west) and D- <br />D' (north- south), Figures 1B and IA, respectively. These figures are considered confidential. <br />EMD (Panels 2 -Right through 6- Right, PR97 -04) -_The mine inflow predictions were generated using a <br />different methodology than was used for the EMD. The discussion and calculations are presented in Section <br />2.05 of this application. The methodology used a mirror -well technique, which should be adequate for <br />• predicting inflows into the mine. <br />PR09 -08 2.04 -10 04/10/09 <br />