ARCHIVED REPORTS_QUARTERLY REPORT - SECOND QUARTER 2008

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approximately 150 feet southeast of extraction well EW-1113. The groundwater recirculation system ran continuously without outage through the end of the quarter. The extraction/injection flow rate was monitored weekly and maintained between the RWQCB required rate of 0.5 to 1.0 gallons per minute (gpm). No significant maintenance issues were encountered this quarter. However, differential between the pressure inlet gauge and pressure outlet gauge of the recirculation system pair was noted to be reduced on 13 June 2008 and the manual globe valve flow rate adjustment would not increase the flow rate above 0.60 gpm. On 16 June 2008, the submerged Grundfos pump within well EW- I IB was increased to 6,000 revolutions per minute (rpm) for ten seconds and then reset to the initial rate of 5,000 rpm. The intent was to spin the pump at an accelerated rate for a short period to clear out any potential sediment or fouling that may have accumulated. Once the pump rpm was reset to 5,000 rpm and flow rate adjustment was restored and again set at 1.00 gpm. The total pump hours of the groundwater recirculation system from 19 May to 27 June 2008 were 932 hours. The total volume of groundwater recirculated from 19 May to 27 June 2008 was 46,147 gallons. The average rate of groundwater recirculated from 19 May to 27 June 2008 was 49.5 gallons per hour or 0.825 gpm. Cumulative recirculation system readings are included in Appendix C. In-Situ Level Troll data transducers were suspended within wells MW-313, MW-413, MW-5B, MW-913, MW-1013, MW-13B and EW-11B via vented RuggedCableTM and level, temperature and pressure data were recorded hourly. Advanced GeoEnvironmental, Inc. performed weekly field downloads of the Troll data to a laptop computer without interruption of Troll data measurements. The hourly Troll data recorded anomalous readings in some wells (MW-3B and MW-513 most notably) which appeared to occur during the weekly data downloads. Troubleshooting was ongoing through the end of the quarter, but was focused on inadequate venting of the well casings at the well box cover. The covers on wells MW-313 and MW-513 were flipped on 25 June 2008 and left untightened and loose to allow venting of the well casing. The anomaly was continuing to be evaluated as the quarter ended. A site visit by an Insitu, Inc. field representative was scheduled for July 2008. Weekly Troll data is included in Appendix C. (Subsequent to the In Situ visit, the transducers were in good working order and the anomalies at MW-313 and MW- 5B were resolved.) The groundwater elevation map (Figure 4) appears to show a hydraulic mound near the injection point(IW-BH2A) and a hydraulic depression near the extraction point(EW-I IB). The mounding near MW-913 is consistent with historical patterns and this mounding will be evaluated in the next monthly report for potential influences of the extraction/injection system when more representative groundwater elevation data are available. The hydraulic depression observed at well MW-513 will also be re-evaluated. 10