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<br />MINREC, INC. ANNUAL HYDROLOGIC REPORT PAGE 4 <br /> <br />1 <br /> <br /> <br /> <br /> <br />1 <br /> <br />OUTFACE 001 -QUALITY <br />YEAR FLOW H COND TDS 1RON <br />1989 16.5 7.9 3598 2512 1.51 <br />1990 17.0 8.1 3157 2129 1.16 <br />1991 20.1 8.1 2890 2018 1.28 <br />1992 19.3 8.0 2722 1805 0.72 <br />1993 22.4 7.9 2643 1738 0.54 <br />1994 21.2 7.6 2627 1710 0.52 <br />1995 32.5 7.8 2435 1663 0.17 <br />1996 36.8 7.8 2082 1441 0.15 <br />The units for the figures in the above table are; flow (gpm), pH (standard units); conductivity <br />(umhos/cm); total dissolved solids (mg/l) and iron (mg/I). Iron was measured as total recoverable <br />until April 1994 when the Colorado Department of Public Health and Environment changed the <br />discharge permit to require iron to be measured as potentially dissolved. <br />' ANTICIPATED IIVIPACT <br />Discharge from outfall 001 may slightly impact the quality of water in North Thompson Creek. The <br />mine water discharge has a low iron content and an acceptable pH, however its conductivity is quite <br />high. A 36.8 gpm flow with a conductivity of 2082 discharging into a receiving stream with a 5 cfs <br />flow and a conductivity of 130 would increase the conductivity of the receiving stream to about 162 <br />which is considered insignificant. <br />' The Colorado Department of Health has implemented new regulations regarding saline discharges <br />into the Colorado River. A discharge of one ton of salt per day can be considered a no-salt discharge <br />by the Department of Health. At the maximum expected flow rate of 40 gpm from the No. 1 Mme, <br />the TDS concentration could be as high as 4150 mg/I and still not exceed the one ton per day of salt <br />discharge limitation. Currently the TDS of the discharge is consistently less than 1500 mg/I. <br />' The entire mine site has been reclaimed and seeded. Good plant growth occurred during 1988 <br />through 1996. During 1992 a study was performed at the mine site that demonstrates that untreated <br />drainage from the reclaimed area contributes fewer suspended solids than untreated drainage from <br />the natural surrounding area, (permit pages 4-19i though 4-19iii). None of the sediment ponds <br />dischazged during the year. <br /> <br />1 <br />