2013-03-14_REPORT - C1982056 (3)

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No unusual observations are noted with respect to Foidel Creek alluvium groundwater levels. The historical increasing conductivity trend in well 001 -S -5 (Figure 32) stabilized in 2004, and appears to be increasing again through the end of 2012. No unusual observations are noted with respect to Fish Creek alluvium groundwater levels. The general water level decline noted in well 006 -AY -1 (Figure 34) since 1995, appears to continue in 2012. Overall, fluctuations at this well are insignificant. No other notable water level observations are apparent based upon review of the 2012 data. Field conductivity readings at this well appear stable over the last few years. Surface Water: 2012 was a significant drought year for Routt County and Colorado. Flows on Foidel Creek, Fish Creek, and Trout Creek were very low in comparison to TC's historic record. A stream gage study was initiated by TC with the aid of a consultant in the fall of 2007, and continued through 2012. 2012 gage results have not been completed by our consultant, Rivers Unlimited, but will be sent as an addendum to this AHR. Stream rating curves will be re- evaluated in 2013. Conductivity concentrations at site 301, 69, and 1005 on Trout Creek appeared somewhat elevated during the spring runoff season in April. This may be the result of upgradient spring runoff flushing through the old P & M mine area. No other water quality impacts of concern were evident at any surface water sites monitored during 2012. Spoil Springs: Recorded 2012 spoil spring discharges did not occur in 2012, probably due to the combination of reclamation at the Fish Creek Tipple, and the drought. Thus, they did not constitute a significant portion of discharge from the TC mine area with the potential to impact off -site areas. Discharges from sedimentation ponds predominately occurred in conformance with applicable CDPS permit limitations and therefore did not constitute significant impacts to receiving waters. Mine Discharge: Mine water discharge site 109 did not discharge to Foidel in 2012. In 2005, TC began redirecting electro- coagulation treated mine water pumped from the Fish Creek Borehole well, underground locations for dust control. Mine water from the Fish Creek Borehole well (which is treated by electro- coagulation) inadvertently discharged to Fish Creek over two days in January 2012 because of a cracked pipeline valve. No other discharge occurred in 2012. The mine pump at 10RT began discharging to Foidel in September 2008 under an emergency discharge permit issued by CDPHE. In early 2009, TC experienced difficulties in consistently meeting WET and iron standards at the pipeline discharge source. In the second quarter of 2009, TC halted all discharge at the discharge source permited under the emergency discharge permit, and re- directed 10RT dewatering to the Area # 1 Pit. The Pit overflow goes via DRMS site 7 to Pond D, which may in turn flow into Foidel Creek via CDPS Outfall 005A (a.k.a. site 84). As indicated earlier, future treatment of TORT mine water is under consideration. Mine Inflow: No unusual occurrences of inflow were noted as a result of the Annual Mine Inflow study. Inflows are within the projected flows presented in the permit. Water quality has not changed significantly and 18