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• characteristics for the Seneca II-W leasehold were available. In 1974, monitoring wells MW-1, MW-2, and MW-3 were completed in the Wadge Overburden, the Wadge Coal seam, and a portion of the interbu rden between the Wadge Coal and Wolf Creek Coal. Although aquifer `f J tests were conducted on MW-1 and MW-2, the results are considered inaccurate since all three wells had leaking grout seals and were later abandoned. In 1980, aquifer tests were conducted on monitoring wells GW-52W-3WC and GW-S2W-4WC, completed in the Wolf Creek Coal, and CW-S2W-1W and -SW, completed in the Wadge Coal. The pumping test at Well CW-52W-1W was unsuccessful due to well failure. During 1987 and 1988, fourteen aquifer tests were conducted on monitoring wells completed in the alluvial, Wadge Overburden, Wadge Coal, Wolf Creek Coal, and Trout Creek Sandstone aquifers. Constant discharge tests (Theis, 1935; Cooper and Jacob, 1946; Neuman, 1975), slug tests (Cooper et al., 1967), and bailer tests (Skibitzke, 1963) were used to determine aquifer characteristics at the Seneca II-W Mine leasehold. The constant discharge and slug techniques involve matching graphs of drawdown/recovery data against theoretical type curves, while analytical solutions were used to determine aquifer characteristics from bailer test data. The results of aquifer testing at Seneca II-W are presented in Table 7-7; specific test data and graphs for all aquifer tests can be found in Appendix 7-3. Statistical summaries for the Wadge Overburden, Wadge Coal, and Wolf Creek Coal aquifers are presented in Table 7-B (only one test was performed on the Alluvial and Trout Creek Sandstone aquifers). Cround water occurs under unconfined conditions in the alluvium as well as in portions of the Wadge Overburden. The remaining aquifers are confined except in outcrop areas. As can be seen in Table 7-7 and Table 7-B, transmissivi ties in the Seneca II-W area are quite low and well yields limit ground water use to domestic or livestock purposes. -4 -1 Hydraulic conductivities are correspondingly low, ranging from 1x10 ft/day to 5x10 ft/day. In most cases, transmissivity and hydraulic conductivity values are also relatively low when compared with the results of other hydrologic studies in the Twentymile Park area. Transmissivity values of 7.5 to 439 ftz/day (30.1 ft'/day geometric mean) were calculated • from aquifer tests of seven alluvial wells at Peabody's nearby Seneca II Mine (Peabody Coal Company, 1988). The 1.4 ft~/day transmissivity calculated for the alluvial aquifer test at the Seneca II- W Mine indicates that the transmissive rate within the alluvial 29