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._ • j • <br />h <br />-2 <br />IV. GeolovY (2.04.5, 2.09.6) <br />The results of roof and floor analyses are still to be <br />submitted to the Division. The samples are presently at the <br />laboratory (see page 8 of Response). The core log showing the , <br />detailed lithology of sampled interval in core hole CH-82-68 <br />and CH-82-69 are not included in Exhibit 19a. The applicant <br />should submit these core logs. <br />The original permit revision application does not contain <br />complete chemical analyses of the Wadge coal seam. Table 1, <br />°Wadge Coal Seam Analysis' contain only an analysis of <br />moisture, ash, heat value, total sulfur, sulfate sulfur and <br />pyritic sulfur. A chemical analysis of coal for an underground <br />mine which will be flooded should also include an analysis of <br />soluble salts and toxic elements contained in the coal. These <br />analyses are important In evaluating the impacts of the exposed <br />coal seam on the mine water quality both during and after <br />mining. <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 underground mine. However, the applicant <br />should develop and run a more sophisticated model of mine <br />inflows and ground water level declines and then construct a <br />series of potentiometrlc maps for periods during and after <br />mining. This model should consider factors such as verticle <br />leakage, discharge/recharge boundary (Fish Creek), recharge <br />boundaries (Foidel Creek and outcrop areas), transition from <br />artesian to water table conditions during drawdown (storativity <br />to specific yield), dips of the aquifers (varying hydrologic <br />head with depth), caving height 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 immage <br />well projected across boundaries. Production wells and immage <br />wells could be added with time to the model to simulate <br />expansion of the mine workings. <br />This model may also serve in simulating post-mining rebound of <br />ground water levels. By converting the production wells to <br />observation wells, the applicant could calculate the time <br />required to re-establish a hydrolic head sufficient to drive a <br />pollutant plume and also to te-establish equilibrium water <br />levels. <br />A similar modeling of ground water at the Middle Creek <br />Underground Mine may be required prior to permitting this mine, <br />and also to evaluate the impacts of all anticipated mining in <br />the general area of the Foidel Creek Mine. <br />