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Getty Task 2 Page 28 March 1, 1983 <br />• 9 <br /> in approzimately 59 days. Using a distance of 800 feet end a days, <br />time of 5 <br /> a drawdown of 612 feet csa be calculated with Equation 8. The piezometric <br /> head at that location and time would be 6588, therefore. The elevation of the <br /> coal at this location is approzimately 6500 feet and the dr awdown caused by <br /> penetration of the second zone would be 88 feet. Since the h eed is less than <br /> the elevation of the top of the overburden aquifer, this value also represents <br /> the amount of drawdown that should be used to calculate the gravity drainage <br /> of the fault zone. Ta ble 3 presents results obtained for the second zone <br /> utilizing Equation 7. <br />Table 3 <br />Estimated liazimum Upward Flow Through Second Fracture Zoae <br />Time Since Upward Flow from Gravity Flow from Total <br />Penetration Underlying Fracture Miae <br />of Zoae Aquifer Zoae Inflow <br />-(days) (BPm) - - ~BPm) <br />- ~-(BPm)--- <br />1 -- - <br />28 -- <br />82 110 <br />7 11 31 42 <br />14 8 22 30 <br />30 5 15 20 <br />60 4 11 15 <br />90 3 9 12 <br />180 2 6 8 <br />360 2 4 6 <br />720 1 3 4 <br />As Table 3 ezhibits, the amount of inflow erpected from the second <br />fracture zone is dramatically less than erpected from the first such zone. It <br />should be noted that the total inflow to the mine is the sum of the values is <br />Tables 2 sad 3 for appropriate times, e.g. the inflow at a time of 60 days <br />after peaetrntion of the first zone is equal to 39 gpm from Table 2 plus 110 <br />gpm from Table 3. Although the additional drawdown caused by the penetration <br />of the second zone will cause the inflow at the first zone to decline more <br />rapidly than indicated by Table 2, the total inflow to the mine remains the <br />• sum of the valves in the two tables because the aquifer senses a total <br />drawdown of 700 feet at the second fracture zone. In other words, once the <br />