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<br />1 <br />r <br /> <br />C~ <br /> <br /> <br />LJ <br />b =thickness of the coal aquifer; <br />Ho = potentiometric head of the water <br />table aquifer above the top of the <br />coal; <br />L = length of the aquifer <br />a = distance from the mine to the coal <br />subcrop. <br />The calculations of inflow to the West mains from the stream <br />beds of Stevens Gulch and East Roatcap Creek used the geometric <br />values as shown in Figure 3 and the transmissivity, T = 9.1 <br />ft2/day which is an average transmissivity of the D and E coal <br />seams in the Red Canyon mine and can be considered a typical coal <br />transmissivity. <br />The second method was published by Klimentov, et. al (1966). <br />In this method the specifici inflow per length unit of the mine <br />opening is calculated by the following equation: <br />q = (K/L)(2MH - MZ - h2) <br /> <br /> <br /> <br /> <br />C <br /> <br /> <br />1 <br />1 <br />where: q = specific inflow per length unit; <br />K = hydraulic conductivity of the coal; <br />L = distance between mine and subcrop; <br />M = thickness of the coal aquifer; <br />H=potentiometric surface above the coal <br />seam; <br />h = difference in elevation between constant <br />head source and mine floor. <br />Both methods indicated very low seepage through the coal <br />into the mine. The seepage in Stevens Gulch could amount to <br />approximately Q = 0.5 gpm and in the East Roatcap area, Q = 0.4 <br />gpm. <br />Increased seepage through the coal can be experienced in the <br />south-western corner of the SW mine sector where the panel <br />development will approach the mined seam subcrop underneath the <br />East Roatcap Creek stream bed. Inflow in this sector was <br />calculated as Q = 3.7 gpm. <br />The conclusion is that inflow into the mine will increase <br />somewhat, but not substantially, when the mine workings approach <br />the areas of the Stevens Gulch and East Roatcap Creek drainages. <br />A summary of inflow values for the mine development after <br />year 1969 is presented in the following table: <br />' I I 7 uuncu.~a:u ru~,i cnvr~ <br />