REP43232 - Laserfiche WebLink

Home Browse Search

' A summary of the staff gauge readings for 1988 is presented in Table 27. A plot of daily mean flow versus time for the Williams Fork River for 1988 is presented in Figure 24. The plot for the Williams Fork River includes the mean monthly flows for the Williams Fork at Hamilton (a discontinued USGS gauging station). For the Williams Fork River, the maximum mean daily flow was 1740 ' cfs, the minimum mean daily flow was 17 cfs and the mean flow was 195 cfs. A plot of minimum, mean monthly and maximum flows measured by the USGS for the Williams Fork River at Cyprus Empire ' Corporation is presently on Figure 25. The flows in the Williams Fork River were near normal in 1987. The flows in the Williams Fork measured to date by Cyprus Empire ' Corporation do not show any significant variation from expected values. ' River Water Quality Summaries of the water quality data are presented in Tables 28 through 31. A plot of upstream and downstream field electrical conductivity measurements for the river is presented in Figure 26. The data indicates that the surface water quality does not show any ' significant variation from expected values. The data from the upstream and downstream station on the Williams Fork River indicate that there is little to no detectable effect of mining on river ' water quality. As expected, conductivity decreases with increasing flow rate in the rivers. This is due to the effects of snow melt and high rainfall diluting the water. The only possible impact may be an increase in the downstream iron concentration; however, this ' increase is well within the error limits of the data. The water quality data for 1988 includes a sample collected in January 1989. IJ 1 1 SPRINGS Spring Flow One spring on the mine site area is being monitored. The spring is the No. 1 Strip Pit Discharge. The No. 1 Strip Pit Discharge is a NPDES monitoring point. There are a few other springs and local permanent "damp spots" in the area; however, their combined flow, is normally less than 10 gpm and are therefore not significant. The measured discharges for the No. 1 Strip Pit are presented in Figure 27. The discharges show a normal seasonal runoff period and low flows in the winter and early spring; with most of the flows being so low that they become too low to measure, in part due to freezing. The average discharge from the No. 1 Strip Pit was 0.5 gpm. Measurable flows at the Haxton Spring were not observed in 1987. The average discharge from the No. 1 Strip Pit has steadily 5