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Pitch Reclamation Project <br />Colorado Mined Land <br />Reclamation Board <br />• 2009 Annual <br />Reclamation Report <br />4.3.2 Groundwater Levels <br />Seven piezometers were installed in the area of the Pinnacle Mine to monitor the <br />piezometric surface within the workings area behind the adit plug. The piezometers <br />are identified as P4 through P10. Piezometer P7 was installed as a replacement for <br />P6, which was lost during plug grouting/construction. The locations of these <br />piezometers are provided in Figure 3. All six piezometers fluctuate seasonally with the <br />highest levels in late May or early June. The water levels are sympathetic with <br />snowmelt and large precipitation events and decrease to stable levels after these <br />events. During 2009, in spite of the increase snowpack and rainfall, the phreatic <br />surfaces in all piezometers showed a comparatively normal spring cycle. The water <br />level data indicates a relatively constant levels or gradual upward trends that have <br />been observed since 2000. A hydrograph of the piezometer water levels is provided <br />as Figure 4. <br />4.3.3 Pinnacle Adit Flow <br />The flow rate from the Pinnacle Adit at PP-01 has been monitored since November <br />1993. The flow from the adit remains in a seasonal pattern of high flows during the <br />short period of spring melt in late May or early June and stable flows of less than 10 <br />gallons per minute (gpm) throughout the year. The measured peak flow for the 2009 <br />season was 29.2 gpm on June 3, 2009. This was lower than the peak discharge in <br />June 2008 of 40.7 gpm. A hydrograph of the Pinnacle Adit flow at PP-01 is provided <br />as Figure 5. The spike in flows observed at PP-01 each spring are likely a result of <br />snowmelt and runoff from surrounding sources originating between the Pinnacle plug <br />and the PP-01 monitoring point. Once the snowmelt period is over, the flow rate at <br />PP-01 decreases and stabilizes at normal levels. <br />4.3.4 Radium and Uranium Concentrations at PP-01 <br />Dissolved radium 226 and total uranium have been monitored at PP-01 since March <br />1994. After construction of the Pinnacle Adit plug in September 1995, both the <br />dissolved radium 226 and total uranium concentrations have stabilized at reduced <br />concentrations. A graph of the radium and uranium concentrations at PP-01 is <br />provided as Figure 6. During 2009, total uranium and dissolved radium 226 levels <br />remained at the reduced concentrations observed over the preceding thirteen-year <br />period. <br />• <br />11