Laserfiche WebLink
Dissolved Salt Load <br />Discharge from the sediment control ponds at Energy Mine No. 3 <br />is expected to increase the dissolved salt load of Middle <br />Creek. The contribution of dissolved salt downstream from the <br />mine was simulated by the applicant using the Stream Water <br />Quality - Continuous Source Program (Sandberg. et al. 19811. <br />The results of this analysis indicate an estimated increase in <br />TDS concentration of 20 mg/1 at one mile downstream, 5 mg/1 at <br />two miles, and less than 1 mg/1 increase near the confluence of <br />Middle Creek with Trout Creek (page 2.05-176a'l. The actual <br />increases seen in TDS concentration due to discharge from the <br />detention basins may be somewhat less during high flow periods <br />and greater during low flow periods. Based on this analysis. <br />discharge from the two detention basins at Energy Mine No. 3 is <br />not expected to have a significant detrimental effect on <br />surface water quality downstream of the mine. Greater effects <br />than those predicted by the modeling have been observed in <br />Middle Creek, below its junction with Foidel Creek; however, <br />these effQCts probably result from contributions from mines <br />located upstream from the Energy Mine No. 3. <br />Ion Balance of Surface Water <br />Asa result of mining operations, the ion balance of surface <br />waters draining the area is being affected. Surface water <br />quality data collected by the applicant from undisturbed and <br />disturbed drainage areas show a trend from calcium-bicarbonate <br />type waters to mixed calcium, magnesium-sulfate, bicarbonate <br />type waters (permit document; Table 29 ). This change in water <br />chemistry will likely be a long-term effect; however, the <br />effect should be less noticeable further downstream due to <br />dilution. The change in ion balance of surface waters draining <br />disturbed and reclaimed areas at Energy Mine No. 3 is not <br />expected to be detrimental to the intended use of surface water <br />downstream of the mine. <br />Summary <br />An analysis of Probable Hydrologic Consequences of the <br />Energy Mine No. 3 has been performed by the applicant, as <br />required under Rule 2.05.6(31. Several effects from the <br />existing and proposed operations have been identified and were <br />discussed above. <br />-30- <br />