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1 • • rir. Terrell Johnson - 2 - October 4, 1985 4. Bedrock we 1.1 08-79-6 is completed in the overburden aquifer downgradient at an anele'to the mine. Well 08-77-58 is also downgradient from the mine adjacent to the southern disturbances. Only field parame`•_ers were taken at these sites. In both cases EC measured by MLRD were higher than values reported by the operator. 5. Sample CYCC38507D is a partial parameter list surface water sample taken at site #29 on lower Middle Creek. The sample is similar in chemical proportions to the sample taken upstream on foidel Cree4;. However, the sulfate and total dissolved solids concentrations are significan*_ly less. This could be due in part to dilution effects from the ;oiael and Middle Creek drainages. This data does compare to data submitted by CYCC. 6. Sample CYCC38507E is a partial list groundwater sample taken at alluvial well 008-AX-l. This well is located in the alluvium of Middle Creek downstream of the mine on the east side of the stream. The MLRD sample closely matched past data supplied by the operator. The utility of monitoring in this location is questionable; it does not appear that this area could be affected by the mine since it is recharged pr-imarily from adjacent undisturbed areas. General It appears that the spoils aquifer is establishing itself as was predicted by the operator. At present, the spoils aquifer does riot appear to be discharging large amounts of water to the PSiddle CreeF: surface water system as evidenced by the surface water monitoring, the `act that spoils well 008-SP-Sa is dry, there are no signs of spoil springs, and the two ponds built in the spoils are not continually discharging. However, the ponds are maintaining a high water level and spoils well 008-SP-Sa located in the Middle Creek pit also shows a fairly high water level especially for this time of year. The application does not predict a spoils discharge to Middle Creek. Rather, it is predicted that the spoils will totally recharge the regional bedrock aquifer system. It may take another year or two for the spoils to fully saturate before it can be assured the spoils will not discharge to the surface water system. The spoils water quality appears poorer than what was predicted in the application. The application predicted a spoil water quality of 2,200 mgJl TDS and an EC of 3,000 umhos. The quality of the Middle Creek pit spoils well was 3,790 mg/1 TDS, an EC of 3,960 umhos/cm, and a sulfate level of 2,570 mg/l. This discrepancy from predicted and observed spoil water quality could be accounted for in the way the leach test was done, the variation in geochemistry, a longer residence time in the spoils, or other environmental factors. Although the discrepancy is significant (72% higher), the spoil water quality is comparable to values found at other mines including the Edna Mine, Seneca and Eckman Park Mines.