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'21 ~ <br />• ~l immediately above and below the coal seam. The lithology of the strata <br /> exposed in the open holes is described on the data sheets in Tables B1 and <br />1, 62 in Appendix 6. The geophysical cogs of these intervals are in the map <br />JJ pocket. The transmissivities determined in the tests represent weighted <br /> mean values far the open intervals. Strata immediately above and below <br /> the coal seam were purposely included in the test interval so that we could <br /> assess the potential mine inflows from adjacent roof and floor rocks should '~ , <br />l fracturing of these strata occur during mining. r ;'' =~ - ' '~~ - ~~~ <br /> J <br /> Well LA 264 was designed to provide an assessment of the water bearing <br /> capacity of the overburden in addition to that provided by the core per- <br />? meability tests. The completion details for this well are included art the <br /> Lest data sheet in Appendix B, Table B3, and the geophysical log is in the <br /> map pocket. Note that the open interval in lA 264 extends from a depth of <br /> <br />~f~j 62 ft. to 276 ft. During drilling, water inflow was encountered at about <br />72 ft. and estimated to be about 15 gpm. No significant increase in dis- <br />, <br />l charge was observed aver the remainder of the hole. Examination of drill <br /> cuttings and the geophysical logs indicate that the water encountered at <br />• 12 ft. was produced from a thin layer of silts tone. The gamma-gamma log <br />'- indicates a washout (hole enlargement) hegi~g 't-7-2.ft. and extending <br /> to perhaps 74 ft. It is probable that a thin fractured zone at this level <br /> accounts for essentially all of produced water. The "aquifer" test con- <br /> ducted at LA 264 consisted of pumping at a constant rate far more than two <br /> hours and the analysis of .the drawdown~ata~eas~lccomplished_usinq the <br /> standar_d__J_acob Method (McWhorter and Sunada, 1977) as show_n__in Figure_5. <br />I! <br />The hydraulic properties determined from these tests are summarized <br />~' in Table 2. Even the largest of the transmissivities in Table 2 is small <br />I' relative to values required for most water supply purposes. T t~average <br />;, permeabilities K are very small and are indicative of v_ery_poor_ ~.vater pro- <br />! during capabilities. The va ues or K shown in the right-hand column riere <br /> obtained by dividing the measured transmissivities by the thickness o.f the <br />I stratum believed to be contributing the water during the tests. In the <br /> case of wells LA 221A and LA 218A, this stratum is the coal seam and the <br />I~ permeability values are those for the coal. The coat permeabilities given <br /> in Table 2 fall within the range of coal permeabilities that we have measured <br />~ <br />I; at other locations. The permeability value of 45.4 ft/d is believed to <br />