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<br />water monitoring site at the Seneca II-W Mine. Site FG1 is located <br />downstream of the south mining area at the mouth of Hubberson Gulch <br />immediately upstream of where it confluences with Dry Creek. As was the <br />case for site FG2, site FG1 was initially established by the USGS in <br />June, 1979 and is formally known as USGS No. 09244464. The station <br />consists of a Parshall flume with a 2.5 foot throat width outfitted with <br />a continuous recorder. The monitoring history at this site is exactly <br />the same as that for site FG2 except that this site is part of the <br />Interim Monitoring Program and thus continues to be monitored for flow <br />and quality. The continuous flow data have been reduced and are <br />reported by water year in Table 26 and graphically displayed on Figure <br />10 (in map pocket). The water quality data are tabulated in Appendix E <br />and statisitcally summarized in Table 27. A trilinear plot of the <br />distribution of major ions is depicted in Figure 3 and a plot of TDS <br />concentrations for the period-of-record is shown in Figure 11. The flow <br />regime at site FG1 is perennial, not intermittent as stated on page 7-80 <br />of the permit application, and fluctuates dramatically as evident from <br />Figure 10. Monthly mean flow has ranged from almost zero cfs in October <br />1979 to a maximum of 15.71 cfs in April 1985. Generally, flow from July <br />through March of each year has averaged below 0.3 cfs; but, from April <br />through June, the rise of the hydrograph is usually dramatic, commonly <br />peaking in April and/or May with a monthly average between 5 and 15 cfs. <br />Because of the above-normal precipitation recorded from 1981 through <br />1985 (see Table 1), it is likely that average and peak flows during a <br />normal percipitation year would be somewhat lower than those measured <br />during the past five years. <br />Similar to the upstream site SG6, the water quality for FG1 is a <br />Mg-Ca-504 type but noticeably less dominated by the 804 ion. Mean TDS <br />concentration is 927 mg/1 ranging from 290 to 1,632 mg/1. From Figure <br />11, it does not appear that there are any distinct trends except that <br />the lowest TDS concentrations do occur during the spring snowmelt when <br />flows are highest. Comparison of the water quality data in Table 27 to <br />receiving stream standards reveals that 13 constituents have exceeded <br />the standards at least once. Table 28 lists the exceedences for each of <br />the 13 parameters. Inspection of this table reveals that total Fe, <br />91 Revised 10/22/87 <br />