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1 <br /> <br /> <br /> <br /> <br />LJ <br />1 <br />1 <br /> <br /> <br /> <br /> <br />tl <br /> <br /> <br />1 <br /> <br />1 <br />MINREC, INC. <br />ANNUAL HYDROLOGIC REPORT <br />PAGE 3 <br />MINE WATER QUALITY <br />The quality of the No. 3 Mine discharge is measured monthly. Prior <br />years monitoring of this discharge has been summarized into a <br />monthly format and is included in Appendix IV. The quality of the <br />discharge from the mine shows little change from previous years. <br />The quantity of the mine discharge during 1990, 1991 and 1992 has <br />averaged 6.7, 6.8 and 5.4 gpm respectively. <br />The quality of the No. 1 Mine discharge is presented in a table in <br />Appendix IV. The quality of the discharge from the mine shows <br />little change from prior years except that since chemical treatment <br />is no longer necessary, the conductivity and total dissolved solids <br />of the mine discharge water has decreased about 25$ compared to <br />1989 measurements. The treatment provided by the long pond is also <br />believed to contribute to the improved quality of the mine <br />discharge. <br />The following table presents arithmetic averages of flow <br />measurements taken during the past four years of the No. 1 Mine <br />dicharge. <br />YEAR FLOW pH COND TDS IRON <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 />The units for the figures in the above table are; flow (gpm), pH <br />(standard units); conductivity (umhos/cm); total dissolved solids <br />(mg/1) and iron (mg/1). <br />ANTICIPATED IMPACT <br />Discharge from the No. 1 mine continues to slightly impact the <br />quality of water in North Thompson Creek. The mine water discharge <br />has a low iron content and an acceptable pH, however its <br />conductivity is quite high. A 20 gpm flow with a conductivity of <br />2722 discharging into a receiving stream with a 5 cfs flow and a <br />conductivity of 150 would increase the conductivity of the <br />receiving stream to about 173 which is considered insignificant. <br />The Colorado Department of Health has implemented new regulations <br />regarding saline discharges into the Colorado River. A discharge <br />