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Status Report; Robinson Seep Investigation Climax Molybdenum Company <br />wall and seepage collection system appear to effectively capture surface and shallow, alluvial <br />groundwater flow through the area. There is likely some small component of flow through <br />fractured bedrock moving around or under the cut -off wall, but the delineation of the extent of <br />seepage indicates a narrowing and closure of the seepage path in the vicinity of the cutoff wall. <br />Short term trends in dissolved iron indicate an overall steady increase of concentrations in well <br />EVMW -1 S since October 2011. This increase has occurred independent of other constituent <br />trends within this and other wells, as well as the apparent absence of dissolved iron in Robinson <br />Lake and the Robinson Lake Seep. Trends in dissolved manganese concentrations in well <br />EVMW -1S were consistent with the observed trends of other constituents in Robinson Lake <br />Seep and EVMW -1 S through September, but higher, increasing concentrations were observed <br />in October and November. Based on these results, it appears that there are other <br />physiochemical conditions or factors, potentially unrelated to upgradient chemistry and <br />hydrologic conditions that may be influencing iron and manganese at monitoring well EVMW- <br />1 S. <br />The closing section of this status report includes summary conclusions, and recommendations <br />for the continuation of the current monthly monitoring program through at least the end of 2014. <br />Several additional data collection and analysis efforts are also identified specifically related to <br />dissolved iron and manganese. Lastly, several potential response actions are identified that <br />may warrant additional evaluation in the event that water quality trends indicate the need to <br />implement additional contingency actions. <br />Tetra Tech, Inc. November 2013 <br />