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Status Report; Robinson Seep Investigation Climax Molybdenum Company <br />Field investigations, consisting of the following phases, were undertaken to evaluate the spatial <br />extent of seepage and potential groundwater flow paths between Robinson Lake and the <br />Robinson Lake seep collection system: <br />• Site reconnaissance to identify potential geological controls for seepage transport <br />and to collect samples of surface water downgradient of Robinson Lake; <br />• Field investigations in August and September, 2013 to delineate seepage by means <br />of field screening and water sampling; and <br />• Field investigations in August 2014 to evaluate the temporal change in seepage <br />migration since 2013. <br />1.3 Previous Water Quality Investigations <br />Following the 2013 field program Tetra Tech (2013) concluded that short-term trends of increasing <br />concentrations of several indicator parameters at monitoring well EVMW -1 S appeared to have <br />stabilized at relatively consistent levels with the exception of dissolved iron and dissolved <br />manganese. Based on long -term trends, concentrations of primary water quality indicators, <br />including sulfate and TDS at EVMW -1 S remained significantly lower than previously observed <br />maximum concentrations at the original monitoring well EVMW. <br />Water quality trends in the Eagle Basin, including EVMW -1 S, indicated no immediate threat to <br />Eagle Park Reservoir water quality. However, monthly monitoring was recommended for 2014 to <br />better understand trends and the effects of seasonality with regards to groundwater chemistry <br />and movement towards Eagle Park Reservoir. <br />Tetra Tech November 2014 <br />