ARCHIVED REPORTS XR0009025 - Laserfiche WebLink

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C A M B R I A P-1, and P-2 at concentrations ranging from 460 to 120,000 ppb TBA was detected in wells MWA through MW-4, P-1, and P-2 at concentrations ranging from 860 to 33,000 ppb TAME was also detected in piezometer P-1 at 310 ppb No other fuel oxygenates were detected in groundwater samples collected from the wells TPHg and BTEX were not detected in any of the site wells, although some reporting limits were elevated AQUIFER PUMP TEST The pnmary objective of the extended aquifer pump test was to implement interim remediation of groundwater beneath the site and to assess the hydraulic properties of the aquifer Personnel Present. Cambria staff scientist Kevin Dolan conducted the field activities, working under the supervision of Project Engineer Dan Lescure Protocol. On October 21, 2002, Cambria conducted a step discharge test on well MW-4 A constant rate pump test on this same well was initiated on this day following the step discharge test Groundwater was extracted using a two-inch diameter Grundfos electric submersible pump • The pump was set approximately six inches above the bottom of the well The extracted groundwater was temporarily stored in an on-site storage tank, and transported via vacuum truck to the Shell refinery in Martinez, California for recycling after completion of the constant rate test The following parameters were monitored during each test duration, flow rate, volume, drawdown, and recharge A totalizing flow meter was used to monitor the flow rate and number of gallons pumped during the tests Pressure head measurements were collected from well MW-4, and piezometers P-1 and P-2 using MimTrollrM pressure transducers Water levels were also checked manually with an electronic water level indicator from these wells and other wells i Samples were collected periodically from the extracted groundwater stream during the test and retained in vials containing hydrochloric acid preservative with no head space These samples were labeled, entered onto a chain-of-custody record, and placed into a cooler with ice for transport to a state of California certified laboratory for analyses The samples were analyzed for TPHg, BTEX, and MTBE by EPA Method 8260B Step Discharge Test Results: The first step was performed at an extraction rate of approximately 0 5 gallons per minute (gpm) This pumping rate was maintained for 78 minutes • until the water table stabilized at 53 55 feet below grade (fbg) A second step was performed at 0955 4