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• RIVERS <br />FLOWS <br />The Williams Fork River flow data is collected by the U.S. Geologic <br />Survey at one continuous gaging station and one staff gage. The <br />Williams Fork River continuous gaging station (WF-2) is near the <br />confluence with the Yampa River, downstream of the #5 Mine <br />discharge. The staff gage (WF-1) is located upstream of the mine <br />discharge points. <br />The flow data for Station WF-2 for 1992 was taken from magnetic <br />format data provided by the USGS. A summary of the staff gage <br />readings for 1992 is presented in Table 29. A plot of daily mean <br />flow versus time for the Williams Fork River for 1992 is presented <br />in Figure 25. <br />For the Williams Fork River at Cyprus Empire Corporation, flows <br />measured by the USGS during calendar year 1992 showed a maximum <br />daily flow of 1240 cfs and a minimum daily .f low of 21 cs. Monthly <br />minimum, maximum and mean flows are plotted for each month of <br />record in Figure 26. The flows in the Williams Fork River during <br />1992 appear below normal for the period of record. These flows <br />including comparison between upgradient, WF-1, and downgradient, <br />WF-2, measured to date, do not show any stream depletion impacts <br />from mine dewatering. <br />• WATER QUALITY <br />Summaries of the water quality data are presented in Tables 30 <br />through 33. A plot of upstream and downstream field electrical <br />conductivity measurements for the river is presented in Figure 27. <br />The data indicates that the surface water quality does not show any <br />significant variation from expected values. The comparisons of <br />data from the upstream and downstream station on the Williams Fork <br />River indicate that there is no detectable effect of mining on <br />river water quality. As expected, conductivity decreases with <br />increasing flow rate in the rivers. This is due to the effects of <br />snow melt and high rainfall diluting the water. <br />SPRINGS <br />FLOWS <br />One spring on the mine site area is being monitored. The spring is <br />the #1 Strip Pit Discharge. The #1 Strip Pit Discharge is a NPDES <br />monitoring point. There are a few other springs and local <br />permanent "damp spots" in the area; however, their combined flow is <br />normally less than 10 gpm and are, therefore, not significant. The <br />measured discharges for the #1 Strip Pit are presented in Figure <br />28. <br />• <br />6 <br />