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2) a moderate change in the ion balance of surface water drainage in the permit and adjacent area; 3) temporary changes in the flow regime of Foidel Creek and Fish Creek; 4) increased runoff and erosion within the proposed permit area during operation; and 5) increased sediment load in drainages within the proposed permit area during operations. The proposed underground operations are affiliated with the adjacent Mine No. 1, 2 and Eckman Park in that they both have the same parent company. Both operations would share certain runoff control and mining facilities. All the predicted impacts are shared with and strongly influenced by the adjacent surface mine, with the exception of changing the flow regimes of Foidel and Fish Creeks. An increase in salt loading within local drainages is the predominant impact of all which are anticipated. Water from the underground workings will be discharged to Foidel and Fish Creeks during the mining operation causing a change in the quality and quantities of surface waters. Following operations, there will be a 350 year hiatus of water quality impacts from the underground mine until the aquifers in Twentymile Park re-establish their potentiometric surface. The water from the flooded workings will then discharge poor quality water to Fish Creek for 3000 - 5000 years. The impacts on water quality from mine inflow waters and from flooded workings discharge will be addressed separately, followed by discussions of flow regime changes and sediment loading projections. Water quality of mine inflow waters is influenced by the quality of water in the Wadge overburden aquifer, the Trout Creek sandstone aquifer, and from the salt plume spreading north from the Mine 1 and Eckman Park backfilled spoils. Although the mine is currently discharging water with TDS levels averaging 2373 mg/1, the applicant predicts that water quality will improve with distance from the surface mine, and its associated salt plume. Further from the surface mine, there would be a greater influence from Trout Creek sandstone inflows, TABLE 11. Amine inflow study performed in December, 1985, showed electrical conductivity values near 4000 umhos/cm in the first 1200' north of the portal, decreasing to 1000 umhos/cm 1200' further north and west, which would seem to validate the applicant's prediction. TABLE 11: Mean Water Quality of Contributors to Mine Inflow Water. (1985 Data) Water Quality Parameter TDS Dissolved Fe Dissolved Mn SO4 (mg/1) (mg/1) (mg/1) (mg/1) Trout Creek Sandstone 890 n/a n/a 241 Wadge Overburden 126 0.49 0.04 65.25 Wells 006-82-38 and 006-82-48 -44-