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Daniel Arnold, Esq. January 25, 2011 Denver Water Page 13 of 21 fault zone intersects the creek near the SW -PL sampling location at an elevation of approximately 6,564 feet and the mine pool is currently at an elevation of 6,587 feet, which is 23 feet higher than the fault -creek intersection. As a result, mine pool water can flow into the alluvium and creek along the fault zone under natural gradient conditions. A continued rise in the mine pool elevation may increase the hydraulic head (driving force) along the fault resulting in an increased potential for the fault to convey mine pool water. The relationship of the borehole and the Illinois Fault with the creek are illustrated on Figure 6, which also shows the July 13 -14, 2010 uranium concentrations in the creek along the mine. The borehole and Illinois Fault zone are in contact with the alluvium between the SW -PL and SW -OS locations. As mine pool water discharges to the alluvial aquifer it flows down valley as depicted on Figure 1 until discharging into the creek as the aquifer begins to pinch near MW -6 and the SW -BOS creek location. This results in the notable increase in uranium concentrations at SW -BOS. The historic relationship of uranium concentrations in the alluvial aquifer (MW -6) and in the creek (SW -BPL) and the mine pool elevation is shown on Figure 3 to illustrate that concentrations are increasing in the creek. The uranium concentrations in the creek are increasingly becoming more and more similar to concentrations in the alluvial groundwater during base flow conditions, and this started when pumping of the mine pool ceased in May 2000. An additional possible cause for the similarity is that untreated water from Sump 1 was recirculated back to Sump 4, which is likely to have facilitated groundwater flow to the creek from the 2002 through 2009 period. Also, there is an apparent increasing trend in uranium concentrations in both the alluvial aquifer and in the creek since about 2007 when the mine pool reached the elevation of the creek in the central mine area. The Schwartz Trend intersects Ralston Creek approximately 1,900 feet downstream of the mine and may provide a conduit for mine pool water to enter the creek. The specific conductance survey of the creek that was performed in November 2008 was designed to investigate this possibility and there was an abrupt increase in specific conductivity at the contact with the Schwartz Trend. Sampling of the creek across the trend was additionally performed in December 2009 and sample results showed uranium concentrations to decrease across the trend while radium 226 concentrations slightly increased. The EPP states that based on the decrease in uranium concentration the trend is not a pathway for mine pool water to reach the creek. Inspection of the historical data from sampling locations upstream of the trend (SW -FBRG) and downstream of the trend (SW -ARH), this appears to be the case. EPP Finding: The maximum seepage from the mine pool is 1.2 gpm. This finding is based on a pumping test in the #2 Shaft a few l Os of feet below the Steve adit level. This seepage rate appears to be low considering that the vertically fractured Illinois Fault zone passes through the mine, and possible discharging open boreholes angled back into the mine from valley floor. Whether the 1.2 gpm rate is accurate or not,