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• few other spring; and local permanent "damp spots" in the area; however, their combined flow is normally <br />less than 10 gpm. and is therefore not significant. 1SP Discharge is a CDPS monitoring point (Outfa11022). <br />There is no sediment pond associated with this spring. Spring water runs down a narrow path through a <br />vegetative filter and discharges directly to the Williams Fork River. The POR discharges for the 1SP are <br />presented in Figure 23 and the 2007 discharge measurements are presented on Figure 24, respectively. The <br />discharge from 1SP increased significantly back in 1989. This may have been due to seepage from the ditch <br />that conveys the 7 North Angle discharge (measured at site 9P3, a.k.a. CDPS Outfall 024)). Site 9P3 <br />discharge began in January of 1989, and has been sporadic. Site 9P3 Discharge rates from 1990 through <br />2003 are significantly lower. 9P3 has not discharged since 2003. Nevertheless, snowmelt and ditch seepage <br />both appear to hive some influence on 1SP discharge, as the discharge typically drops to just a few gpm from <br />January through May with a small peak typically in March coinciding with spring runoff. 1SP is typically dry <br />from July throug',h November. <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 1SP 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. Figure 26 illustrates <br />the variable nature of total recoverable iron concentrations in 1SP discharge. Since 2002, there has been a <br />gentle upward trend in iron concentrations, however these levels are still within historic ranges seen for this <br />site. BTU EC wi l continue to monitor this trend. <br />3.2.3 Ponds <br />With the exception of Outfa11003 (discussed under section 3.1.2), there was no recorded discharge from the <br />other on-site sediment ponds in 2007. <br />4.0 SUMMARY AND CONCLUSIONS <br />The subject mine: site ceased active mining operations in 1995, and has been inactive to date, thus, total mined <br />acreage did not change in 2007. The mine was subsequently placed in Temporary Cessation under TRO1-32. <br />Temporary Cessation status ended in the second quarter of 2006, when BTU EC re-activated full water <br />monitoring activities in anticipation of future re-activation of the mine site, and because a bond release <br />application was also being contemplated for the Utah Tract and Williams Fork Strip Pit portions of the mine <br />property. With the exception of anomalous elevated conductivity values detected in wells TR-4 and 81-01, <br />no significant, unpredicted, or adverse environmental impacts were noted during hydrologic monitoring for <br />2007. BTU EC will examine the anomaly further in order to come up with an explanation. DRMS <br />monitoring requirements were met. <br />Page 7 <br />G:~Environmental~Eb'IPIItE~AHR~2007~Empire2007AHR.doc <br />