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The flow data for WF -2 was historically provided by the USGS, however, monitoring of the Williams Fork <br />stations was discontinued in 2001. Historically, comparisons between up gradient site WF -1, and down <br />gradient site WF -2, have not show any stream depletion impacts from mine dewatering. In October 2006 the <br />State Division of Water Resources (Office of State Engineer) reactivated the site. Data for the former USGS <br />site can be found on their website under station No. WMFKMHCO. A copy of the daily average flow data at <br />this site for 2012 is provided at the back of this AHR under Support Data. <br />Summaries of WF -1 and WF -2 water quality data are presented in Tables 27 through 30. A plot of upstream <br />and downstream dissolved solids measurements for the river is presented in Figure 22. Water quality data <br />does not show any significant variation from expected values. The comparisons of data from the upstream <br />and downstream station on the Williams Fork River indicate that there is no detectable effect of mining on <br />river water quality. Dissolved solids decrease with increasing flow rate in the rivers, due to runoff dilution. <br />3.2.2 Springs <br />There is one active spoil spring on the mine site area, known as the No. 1 Strip Pit Discharge, or 1 SP. There <br />are a few other springs and local permanent "damp spots" that flow sporadically in the spring; however, their <br />combined flow is normally less than 10 gpm and is therefore not significant. l SP Discharge is a CDPS <br />monitoring point ( Outfall 022). There is no sediment pond associated with this spring. Spring water runs <br />down a narrow path through a vegetative filter and discharges directly to the Williams Fork River. The POR <br />discharges for the 1 SP are presented in Figure 23 and the 2012 discharge measurements are presented on <br />Figure 24, respectively. The discharge from 1 SP increased significantly back in 1989. This may have been <br />due to seepage from the ditch that conveys the 7 North Angle discharge (measured at site 9P3, a.k.a. CDPS <br />Outfall 024). Site 9P3 discharge began in January of 1989, and has been sporadic. Site 9P3 Discharge rates <br />from 1990 through 2003 are significantly lower. 9P3 has not discharged since 2003. Nevertheless, snowmelt <br />and ditch seepage both appear to have some influence on 1 SP discharge, as the discharge typically drops to <br />just a few gpm from January through May with a small peak typically in March coinciding with spring runoff. <br />1 SP is typically dry from July through September, may flow briefly in October through December, and stops <br />flowing again in January and February due to freezing. <br />Summaries of the water quality data for this spring are presented in Tables 31 and 32. A plot of POR total <br />dissolved solids for 1 SP is presented in Figure 25 and POR iron concentrations are presented on Figure 26. <br />Figure 25 indicates TDS concentrations that are consistent with historic concentrations, with the exception of <br />an elevated value in late July. This may be related to an earlier clearance of cat tails and other vegetation <br />from in front of the site's weir. The site ceased flowing shortly thereafter. Figure 26 illustrates the variable <br />nature of total recoverable iron concentrations in 1 SP discharge. Since 2002, there has been a gentle upward <br />Page 7 <br />G \Environmental\EMPIREWILLIAMS FORK \Water Permits & Related \AHR\2012 \Empue2012AHR.doc <br />