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Permit C-81-071 1994 Annual Hydrology Report • year and a very rapid increase in flow during the spring runoff followed by a moderately rapid decrease in flow. Water Quality The summary of the 1994 spoil spring field data is presented on Table 47. The summary of the water quality data for Station 114 is presented on Tables 51. Additional spoil spring data is presented on Tables 48 and 49 for Mine I and on Table 50 for Mine 2. Plots of the historic water quality data for Station 114 are presented on Figures 43 and 44. The data for the Mine 1 spoil springs flow show a maximum field conductivity value of 6510 umhos/cm with an average value of approximately 3260 umhos/cm during the 1994 water year. During the winter when Foidel Creek flows are dominated by spoil spring discharges, the creek's conductivity level approaches that of the spoil springs. The conductivity of the spoil springs shows temporal fluctuations that most likely reflect spoil recharge events of low TDS snowmelt. The lowest TDS concentrations in the spoil springs occur during the Spring snowmelt period. Figure 51 indicates that the water quality in Foidel Creek is dominated by the water quality of the discharge from Pond A. Pond A receives the discharge of the largest spoil springs. The spoil spring 114 and the discharge from the former Pond 7 area are characterized by high dissolved solids, calcium, magnesium, sulfate and SAR compared with bedrock groundwater, other spoil springs and unaffected surface waters. Station 114 also shows comparatively high • manganese and high nitrate levels. Most of the Mine 1 spoil springs have elevated manganese levels. Due to the small size of the flows and the low conductivity (2690 umhos/cm, maximum reading and 150 umhos/cm average in 1994) the spoil spring discharges from Mine 2 have no impact on Fish Creek. EFFLUENT MONITORING A number of sedimentation control structures at Mine 1 and 2 are monitored. Of these only Stations 39 (Pond A), 84 (Pond D) and 87 (Pond F) at Mine 1 had significant flows during the 1994 irrigation season. Stations 57 (Pond H), 41 (Pond K), and 91 (Pond M) showed minor or no flows only during the spring runoff. None of the stations at Mine 2 had significant flows in 1994. Most of the Mine 1 ponds are in the Foidel Creek drainage, only Pond H (Site 57) is in the Middle Creek drainage. Pond M on Mine 2 is in the Fish Creek drainage. Pond D (Site 84) receives inflow from the waste rock disposal area as well as well as runoff from the surface mine. Pond K (Site 41) drains to Foidel Creek and had no discharge in 1994. Flows The flow rate data for the effluent stations are summarized on Table 52. The historic discharge • data for the ponds with significant 1994 water discharges at Mine 1 are presented in Figures 43 and 46 through 49. Discharges from these ponds are affected by seasonal variation in surface EP4TE%T.DOC 03/17/97 Page 7