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<br />not immediately appear following mining as a considerable <br />amount of time is necessary for the spoil to resaturate and <br />ground water flow directions to reestablish. Since most of <br />the mining to be conducted will stax•t at the coal crops and <br />progress dow:ngradient, there is no saturated portion of these <br />units upgradient of the mining to contribute ground water to <br />expedite the resaturation of the upg:radient spoil by natural <br />ground water through flow. Each year's snowmelt and the <br />limited rainfall are the only avenue:: by which the spoil will <br />resaturate. This process will require considerably longer <br />than 107 days. <br />55. The use of the term "regional gradient" on Page 7 of Chapter <br />17 was merely to point out that if the gradient of the <br />potentiometric surface were zero, there would be no ground <br />water throughflow into the pit and the q, term, which <br />represents t:he flux into the pit fx•om ground water through <br />flow normal to the pit, would be zero. Thus, the pit inflow <br />computation would simplify to one of accounting for pit <br />induced inflow from ground water storage only, which only <br />involves the storage flux term qa. Yes, this is provided <br />mainly for illustrative purposes. <br />56. A complete demonstration of how wet pit areas were arrived at <br />was given to CDMG by PWCC hydrologists on February 1, 1995. <br />The wet areas are calculated by overl.ayinq the potentiometric • <br />surface maps. on the tOD- and bottom-of-coal contour maps with <br />yearly mining divisions. No calculations are performed; <br />rather, the portions of the overburden and coal pit bottoms <br />that are locrer in elevation than the potentiometric surface <br />are measured using a digitizer coupled with a PC. The <br />measured wet. areas are presented as part of Attachment 17-2 to <br />Tab 17. <br />57a. All input parameters and the calculations performed for the <br />Theis pit pumpage drawdowns are pre~:ented in Attachment 17-3 <br />to Tab 17. Transmissivity, times, and pumping rates were <br />obtained from the pit inflow model outputs presented in Tables <br />17-2 throug}1 17-5 in Tab 17. <br />b. The transmi:asivity values for each of the units (overburden <br />and coal) are taken from Tables 17-2 through 17-5 which <br />summarize the output values from the pit inflow model run. <br />Transmissiv:ities in the model output vary from year to year <br />with saturated thickness (T=Kb). 7'ransmissivities selected <br />for the Theis drawdown analyses were those specified for the <br />highest pit inflow years. Hydraulic conductivity values input <br />into the pit inflow model are taken from representative <br />aquifer test values in the different areas of the proposed <br />mine (i.e., Wells YOV9, YOV28, YOV30,. YW28, YW29, YW30, YWU29, <br />YWU30, and YWC31) and presented in Table 17-1. <br />c. See response to 57a. All Theis drawdown calculations are <br />presented in Attachment 17-3 to Tab 17. SCC discovered that • <br />14 <br />