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<br />-29- <br />areas. This aquifer has a low permeability and is only 70 feet thick. <br />Therefore, springs and seeps issuing from this aquifer are not expected <br />to contribute significantly to surface flows, and any resulting depletion <br />of spring flows from the mininy operation will not significantly impact <br />the surface water system. <br />According to the 1982 State Engineer's well records, there is only one <br />water well, about 2 miles from the Foidel Creek mine, completed in strata <br />overlying the Wadge coal seam. This well is located in the SW 1/4 of the <br />SE 1/4 of Section 22, R86W, T5N and in strata about 1000 feet above the <br />Wadge seam. The owner of record is Mr. Ashley. This well is 65 feet <br />deep and may be drawing water from the upper Williams Fork Formation or <br />the lower Lewis Shale. The mining operation will not impact this well, <br />given the distance from the mine to the well and the thickness of low <br />permeable overburden strata between the Wadge seam and the aquifer where <br />the well is completed. <br />The applicant currently pumps ground water from the Wadge-overburden for <br />use in its operations. This use of water will not impact any adjacent <br />wells or springs. <br />The Foidel Creek underground mine may impact the quality of ground water <br />in bedrock and alluvial aquifers during and after mining. During mining, <br />the impacts to ground water quality will be limited to a minor <br />degradation in alluvial water quality in the Foidel Creek stream/alluvial <br />system. This degradation of quality will be due to a higher salt load in <br />the mine discharge than in the stream. <br />The mine development waste pile will not degrade ground water quality <br />during or after mining. This waste rock will be placed in an old strip <br />pit above the projected spoil aquifer water level and then covered with <br />sufficient backfill and soil to ensure that the waste material does not <br />enter the Foidel Creek stream/alluvial system. <br />The Foidel Creek Mine will not significantly impact the quality of ground <br />water in bedrock aquifers during operations. <br />The water quality measured in the wash-bay well (completed in the spoils <br />aquifer) adjacent to the proposed underground mine portal is poor, with a <br />total dissolved solids (TDS) concentration of about 3000 mg/l. To <br />minimize the handling of this poor quality water during mining, the <br />applicant is proposing to partially backfill the face-up pit and drive <br />inclined entries into the Wadge seam. Uuring backfilling, 15 feet of low <br />permeable clay and silt subsoil will be compacted against the highwali. <br />Use of incline entries to the mine workings will also increase the width <br />of undisturbed low permeable rock strata between the spoils aquifer and <br />the mine workings. This compacted low permeable layer and the low <br />permeability of the strata between the pit and the underground mine <br />workings will minimize the handling of degraded spoils waters by 1) <br />lengthening the flow path between spoils and mine, 2) lowering the flow <br />rate, and 3) eliminating the need to dewater the spoils aquifer. <br />