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_ umhos/cm, maximum reading, in 1993) the spoil spring discharges from Mine 2 have no impact on Fish Creek. EFFLIIENT MONITORING The 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 1993 irrigation season. Stations 55 (Pond Gj, 57 (Pond H), 41 (Pond K), and 91 (Pond M) showed minor flows only during the spring runoff. None of the stations at Mine 2 had significant flows in 1992. 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 underground mine discharge water and the waste rock disposal area as well as runoff from the surface mine. Pond G (Site 55) receives runoff from the surface areas of both the underground and surface mines. Pond K (Site 41) drains to Foidel Creek, and had limited discharge due to a cracked riser in the spring of 1993. Flows The flow rate data for the effluent stations is summarized on Table 55. The historic discharge data for the ponds with significant 1993 water discharges at Mine 1 are presented in Figures 42 and 45 through 48. Discharges from these ponds are affected by seasonal variation in surface runoff and spoil springs. All of the plots • show the typical seasonal variation with high flows during spring runoff. Historically, discharges from the ponds ceased in the summer and did not begin again until the next spring. Three ponds, A (Site 39), D (Site 84) and F (Site 87), began discharging year- round in late 1984. This is due to the spoil springs located in the drainages of Ponds A and F and the underground mine discharge to Pond D. Due to utilization of Site 114 and Site 87 for emergency water supplies by Twentymile Coal Company, neither site 114 nor 87 discharged for most of the 1993 water year. Pond A now has a base flow of approximately 0.7 cfs, Pond D 0.26 cfs and Pond F 0 cfs. Pond F did not discharge significant amounts in the 1993 irrigation season, and showed a decreased flow since 1991, due to periodic pumping of the pond for underground mine water use. The discharge from Pond D also increased in 1993 due to increased discharge from the underground mine to Pond D. Since 1984, flows from these ponds have changed Foidel Creek from an ephemeral to a perennial stream. Peak discharges from the Ponds do not seem to have changed significantly because the spoil spring water would have discharged as snowmelt runoff anyway. Water ouality Summaries of the water quality data for the Mine 1 ponds are presented on Tables 57 through 71 and on Figures 44 and 49 through