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• system is at the low end of that determined at the Seneca II Mine. <br />Stewart (1983) provides data for the Wadge Overburden; transmissivity values range from <br />3.1 to 43 ft~/day. Seneca II-W transmissivity values for the Wadge overburden range from <br />0.32 to 72.0 ft'/day. <br />Aquifer tests of six Wadge Coal monitoring wells, performed by Peabody personnel, yield <br />transmissivi ties of 0.03 to 0.36 ftz/day, and hydraulic conductivities of 3x10-3 to 1x10-1 <br />ft/day. Stewart (1983) lists Wadge Coal transmissi vities ranging from 0.2 to 95 ftz/day, <br />and hydraulic conductivities of 0.1 to 0.6 ft/day. Again, aquifer values determined in <br />the Seneca II-W area appear to be at the low end of the values determined for the region. <br />Calculated tra nsmissivities and hydraulic conductivities for the Wolf Creek Coal are 0.001 <br />-4 -2 <br />to 0.20 ft=/day and 1x10 to 1x10 ft/day, respectively. Although no aquifer <br />characteristics for the Wolf Creek Coal could be found in the literature, Stewart (1983) <br />gives a transmissivity of 0.4 ft2/day and a hydraulic conductivity of 0.007 ft/day for the <br />Wolf Creek Coal and Underburden. <br />• <br />A pumping test was conducted at a Seneca II-W production well completed in the Trout Creek <br />Sandstone. The results of this test provide a transmissivity of 23.3 ft~/day, and a <br />hydraulic conductivity of 1x10 1 ft/day. Stewart (1983) describes the Trout Creek <br />Sandstone as having a transmissivity of 1 to 2800 ftz/day, and a hydraulic conductivity of <br />0.006 to 4 ft/day, Hydraulic conductivity data from the U.S. Geological Survey gives a <br />geometric mean of 5.1x1D-3 ft/day for the Trout Creek Sandstone. <br />As indicated by the information presented above, aquifer characteristics measured by <br />Peabody personnel at the Seneca II-W leasehold are generally at the low end of the range <br />of values determined for the region. Aquifer yields at Seneca II-W may be relatively low <br />due to low secondary porosity. Brogden and Giles (1977) report that well yields are <br />higher in the Twentymile Park area where fracturing is extensive. However, U.S. <br />Geological Survey data indicate that the effect of fracturing on hydraulic conductivities <br />in the Twentymile Sandstone is relatively insignificant, since pe rmeabiliti es measured in <br />the field (via aquifer tests) and in the laboratory (of unf ractured samples) were not <br />significantly different (Stanley C. Robson, written communication, 1987). Stewart (1983) <br />• reports that fractures within the Trout Creek Sandstone are widely spaced (tens of feet) <br />and do not appear to be an important factor affecting permeability. Cementation is <br />33 <br />