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. <br />-z- <br />IV. Geology (2.04.5, 2.04.6) <br />The results of roof and floor analyses are still to be submitted to the <br />Division. The samples are presently at the laboritory (see page 8 of <br />Response). The core log showing the detailed lithology of sampled <br />interval in core hole CH-82-68 and CH-82-64 are not included in Exhibit <br />14a. The applicant should submit these core logs. <br />The original permit revision application does not contain complete <br />chemical analyses of the Wadge coal seam. Table 1, "Wadge Coal Sewn <br />Analysis" contain only an analysis of moisture, ash, heat value, total <br />sulfur, sulfate sulfur and pyritic sulfur. A chemical analysis of coal <br />for an underground mine which will be flooded should also include an <br />analysis of soluble salts and toxic elements contained in the coal. <br />These analyses are important in evaluating the i+npacts of the exposed <br />coal seam on the mine water quality both during and after mininy. <br />VII. Protection of the Hydrologic Balance (2.05.6(3)) <br />Map l0a does not contain contours of equal water level decline <br />surrounding the underyround mine. However, the applicant should develop <br />and run a more sophisticated model of mine inflows and ground water level <br />declines and then construct a series of potentio~netric maps for periods <br />duriny and after mining. This model should consider factors such as <br />verticle leakage, discharge/recharge boundary (Fish Creek), recharge <br />boundaries (Foidel Creek and outcrop areas), transition from artesian to <br />water table conditions during drawdown (storativity to specific yield), <br />dips of the aquifers (varying hydrologic head with depth), caving height <br />over entries and panels, etc. <br />This analysis may be best handled using a well field model with <br />production well along mine entries and panel areas, and i~n~nage well <br />projected across boundaries. Production wells and im~nage wells could be <br />added with time to the model to simulate expansion of the mine workinys. <br />This model may also serve in simulating post-mining rebound of ground <br />water levels. By converting the production wells to observation wells, <br />the applicant could calculate the tune required to re-establish a <br />hydrolic head sufficient to drive a pollutant plwne and also to <br />re-establish equilibriwn water levels. <br />A similar modeliny of yround water at the Middle Creek Underground f4ine <br />may be required prior to permitting this +nine, and also to evaluate the <br />impacts of all anticipated mining in the general area of the Foidel Creek <br />Mine. <br />The applicant should provide td the Division copies of the mine water <br />quality analyses which were used in calculatiny the impacts of the Foidel <br />Creek Mine. The 800 my/1 value for T.U.S. which was used in these <br />calculations is consideraoly lower than T.D.S. values in mine discharyes <br />frdm other coal mines on the western slope. Also, stagnation of water <br />within the mine upon its closure nay produce levels of T.D.S. as much as <br />10 time higher than in an active mine. <br />