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5 Mine well discharge is Colorado Department of Public Health and Environment's (CDPHE's) CDPS <br />discharge point 003. The 7 North Angle discharge is CDPS discharge point 024 (which did not flow in 2012). <br />Summaries of the available water quality data for the mine discharge sites are presented in Tables 17 through <br />20. <br />The No. 5 Mine discharge water quality (Figure 18) indicates dissolved solids concentrations consistent with <br />historic values (typically under 1000 mg/L), consistent with pre - Temporary Cessation values. There was no <br />discharge from the 7NA well in 2012. The average total dissolved solids (TDS) concentration for the No. 5 <br />mine dewater well around 900 mg/l in 2012. Note that there was one TDS anomaly of 1530 in December <br />2008. Subsequent TDS values obtained in 2012 are within the normal historical average. Historical <br />fluctuations were historically related to the accumulation of water in the North Angle Sump location while the <br />pump was out of order. This water was allowed to equilibrate within old workings and subsided longwall <br />panels. The maximum concentration represents the equilibrium concentration and also provides an indication <br />of the expected post mining TDS concentrations in rubblized zone of underground mine workings. Likewise, <br />this decrease illustrates the effects of flushing upon the TDS concentrations with normal periodic discharge. <br />3.1.3 ALLUVIAL WELLS <br />Water Sediments in the Williams Fork River Alluvium are monitored via three alluvial wells in the general <br />area of the loadout facilities and underground discharge sediment ponds. These include wells AVF -3, AVF -5, <br />and AVF -6. Water quality data for these three wells is provided in Tables 21 through 26. Conductivity data is <br />provided in Figure 21.2012 data indicates no significant impact on alluvial water quality or levels. <br />Historically, groundwater levels in the alluvium have remained fairly regular, with normal seasonal <br />fluctuations, apparently related to changes in river levels. Ground water levels for these wells is plotted in <br />Figure 19. The data indicates no impact on alluvial water levels related to mining. <br />3.2 Surface Water Monitoring <br />3.2.1 Rivers <br />There are two rivers in the vicinity of the mine site. The Yampa River, flows in a southeasterly direction <br />across the mine site. The Yampa River drains most of the northeast corner of Colorado and part of south - <br />central Wyoming. The second river is the Williams Fork, which is a major tributary of the Yampa River. The <br />Williams Fork River joins the Yampa River on the mine property. Monitoring data is collected for the <br />Williams Fork River. <br />The United States Geologic Survey (USGS) had one gage station and one staff gage for collection of <br />Williams Fork River flow data (former site 09249750). The Williams Fork River gage station (WF -2) is near <br />the confluence with the Yampa River, downstream of the Eagle No. 5 Mine discharge. The staff gage (WF -1) <br />is located upstream of the mine discharge points. WF -2 is also monitored concurrent with WF -1. <br />Page 6 <br />G \Environmental\EMPIREWILLIAMS FORD \Water Permits & Re1ated\AHR\2012 \Empire2012AHR doc <br />