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FOURTH QUARTER 2007 GROUNDWATER TREATMENT FACILITY MONITORING REPORT FORWARD LANDFILL WDR ORDER NO.R5-2003-0080 During a site visit on October 16,2007,a field technician attempted to measure the depth to water in EW-2.The technician determined that the depth to water was greater than 107 feet below the top of the well casing(btoc)when the pump was running.The technician was unable to measure the depth to water because of an obstruction at 107 feet btoc.The top of the pump is located more than 110 feet btoc.The technician turned off EW-2 and allowed the well to recharge for 1 hour,and then measured a depth to water of 67 feet btoc.The technician then turned on EW-2,and the depth to water increased from 67 feet btoc to more than 107 feet btoc in several seconds.Operation of the pump appeared to rapidly draw down the water table surface to the pump intake.The technician throttled the globe valve located at the wellhead to slightly restrict the well flow rate and reduce the chance of pump cavitation.The globe valve was throttled until the maximum safe operating pressure of the upstream piping(100 pounds per square inch)was reached. During first quarter 2008,CH2M HILL will evaluate operation of EW-2 and determine if additional field measurements are required.CI-12M HILL will also evaluate whether redevelopment of EW-2 and repair or replacement of the submersible pump are necessary. Results of the evaluation will be discussed in the First Quarter 2008 Groundwater Treatment Facility Monitoring Report. An electrician visited the GTF on November 19,2007,to troubleshoot the plant flow meters. The electrician determined that the GTF main plant flow meter program parameters had reset to the default values and,therefore,both the instantaneous flow rate and the totalized flow were being computed improperly. It is believed that the program parameters reset between October 2 and 16,2007.The electrician successfully reprogrammed the GTF main plant flow meter.The electrician then recalibrated each extraction well flow meter individually against the GTF main plant flow meter.After calibration,the GTF,EW-1,and EW-2 continued operating. During fourth quarter 2007,the GTF shut down four times because of power outages on October 12,November 4,December 7,and December 16.The GTF was restarted following each power outage on October 12,November 5,December 7, and December 18,respectively. 3.0 Influent and Effluent Monitoring Under WDR Order No. R5-2003-0080,effluent samples are analyzed as follows: • Monthly for pH,specific conductivity,and VOCs • Quarterly for total dissolved solids • Annually for dissolved inorganics All parameters were analyzed during fourth quarter 2007. Figure 1 shows the effluent monitoring location.Table 2 presents the results of the effluent monitoring performed during fourth quarter 2007. Appendix A contains the effluent monitoring field sampling logs and laboratory results for fourth quarter 2007. The current WDRs stipulate that the concentration limit for VOCs in the effluent is non- detect. No VOCs were detected in the GTF effluent samples collected during fourth quarter 2007. RDD/0111 10101(NLH3684.DOC) 2