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c ~ The applicant predicts that the increase in salt leading would be a long- term effect based upon studies at Trout Creek (p. 780-126hhhhh and 780-126iiiii). This does not seem likely given the differences between the two minsites. At Trout Creek, the spoil aquifer discharges to Trout Creek. This increased TDS in the spoil aquifer would provide a long- term source for increased salt loadine in the stream. At the Kerr mine site, the ephemeral draws crossing the permit area discharge to the ground water system. Thus changes in ground water chemistry would not effect surface water chemistry. After pit dewatering ceases and the sediment ponds are removed, salt _'oading should drop to natural levels. 3. Change in surface water ion balance Data collected by the applicant indicates a change from a calcium- bicarborate type baseline water to a sodium-bicarbonate and magnesium- sulfate type affected water. These changes, along with the anticipated salt loading, could cause the water quality to be somewhat less suitable for stock water or irrigation. (780-126jjjjj) SAR values would be increased. However, none of these charges including salt loadine would be significant enough to affect surface water usage. Surface water quality would sti1Z be well below recommended stock water standards for total disolved solids (7000 mg/I). Affected surface waters, like the baseline waters, would c_'assify as medium salinity, Zow alkali hazard irrigation waters. Based upon studies at Trout Creek (p. 780-126hhhhh and 780-126iii) the applicant has predicted that t::ese charees would be long-term. As discussed above, hudrolocic conditions at the two minesites are different. At the Kerr minesite, the ephemeral streams crossing the minesite discharge to the bedrock around water system. Therefore, Zong-term changes in bed rock ground water quality would not effect surface water duality in the ephemeral streams. Af.er ;pit dewatering ::as ceased, the pits have been backfilled, graded, and topsoiled, and sediment ponds are removed, surface :cater chemistry should return to baseline conditions. TIPPLE SITE Surface Plater tJO effects on the quantity of surface flow have been identified. Runoff from the permit area flows to a sediment pond before being released to the irrigation ditch at the north boundary of the property. 19onitoring of pond effluent has not identified any of the water duality effects described for the minesite (see Table ZO). The applicant maintains that coal dust blown into the marsh has not affected water quality. The water quality data provided in Table 10 neither supports or dissapprores thisc~nclusion. Additional investigations should be undertaken. -9-