REP51867

• Permit No: C1981071
• IBM Index Class Name: Report
• Doc Date: 2/16/2000
• Doc Name: 1999 ANNUAL HYDROLOGY REPORT PN C-81-071
• Annual Report Year: 1999
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

• EFFLUENT MONITORING
A number of sedimentation control structures at Mine 1 are monitored. Of these only Stations
39 (Pond A), and 84 (Pond D) had significant flows during the 1999 ircigation season. Stations
57 (Pond H), and 87 (Pond F) showed no flows or minor flows only during the spring runoff.
Most of the Eckman Park and Mine 1 ponds are in the Foidel Creek drainage, only Pond H
(Site 57) is in the Middle Creek drainage. Pond D (Site 84) receives runoff from the waste rock
disposal area as well as runoff from the surface mine. In addition, mine water from the Foidel
Creek underground mine is also pumped to Pond D
Flows
The flow rate data for the effluent stations are summarized on Table 41. The historic
discharge data for the ponds with significant 1999 water discharges at Mine 1 are presented in
Figures 64 through 75. Discharges from these ponds are affected by seasonal variation in
surface runoff and spoil spring flows. 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, D, and F and the past underground mine discharge to Pond D. Sites
114 and 87 experienced extended periods of no discharge during 1999.
During the 1999 irrigation period, Pond A exhibited a mean flow of approximately 1.29 cfs,
Pond D 0.41 cfs and Pond F 0.07 cfs. Pond F did not discharge significant amounts in the
1999 irrigation season, and has shown a decreased flow since 1991, due to periodic pumping
of the pond and Spring 114 for mine use. The discharge from Pond D is shown on Figure 73.
• 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 probably have discharged as snowmelt runoff anyway.
Water Quality
Summaries of the water quality data for the Mine 1 and Eckman Park ponds are presented on
Tables 42 through 45. The field conductivity data shows some typical seasonal variation: the
water quality improves during spring runoff. Ponds A, D, F, and H appear to be impacted by
spoil spring inflows. The discharge rates from H are not significant during irrigation season
and therefore do not cause any significant impacts.
For the ponds affected by spoil springs, increased calcium, magnesium, sulfate, dissolved
solids, and SAR are typically observed. No significant changes in parameters were observed
for the ponds during the 1999. Conductivity and TDS levels observed on Trout Creek have
recently been observed at levels lower than predicted by the CYCC PHC. The levels
documented during 1999 at site 1005, the downstream monitoring site established for Permit
No. C-82-056, were well below 2000 mg/I and therefore likely did not cause or have the
potential to cause material damage. The water quality of Trout Creek was better than
maximum levels predicted in the past salt-loading calculations performed as part of the
"probably hydrologic impacts" section of the mine permit application with a maximum value of
590 mg/I recorded in September of 1998.
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