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' 14 April 2006 • AGE-NC Project No 95-0184 ' Page 2of5 21 SVE PILOT TEST The pilot test was initiated at 8 30 am and continued for approximately 8 hours, after the initial four hours (phase I), the extraction well was switched from VW-5A to VW-513 (phase H} An induced ' vacuum potential was applied to each casing, respectively of VW-5A and VW-5B The vacuum-induced pressure reduction was monitored at surrounding observation points (VW-5A/13, ' VW-2A,VW-3,VW-4,and EW-1)with air-tight well caps pre-connected with Magnehelic vacuum gauges fitted to each observation well A sample port was tapped into the PVC near the wellhead and a portable organic vapor meter equipped with a photo-ionization detector (PID Thermo ' Environmental 580, 10 0 eV, calibrated to isobutylene) was used to measure organic vapor (OV) concentrations The organic vapor concentrations,the induced vacuum potential at the observation points, extracted soil gas flow rate, and revolutions per minute (RPM) of the SVE unit were ' measured at 0 25-hour to 0 5-hour intervals and logged on field sheets Pilot test data are summarized in Table 1 L41' � � 4A�ati A Solinst water level meter was used-to measure the depth to ground water in monitoring wells MW-1 through MW-3,rQEdT�W-5(A-�},vapor wells VW-2(A-4, VW-3, and VW-4, and ground water extraction wells EW-1 ;r b�lative to the tops of the well casings prior to the initiation of the SVE pilot test Depths to groundwater were re-measured in wells MW-2,MW-3,and VW-3 just prior to the termination of the 8-hour test, water levels had not changed significantly over the duration of the test in any of the wells monitored 22 SVE PILOT TEST SAMPLING AND ANALYSIS A total of eight soil gas/vapor samples were collected during the pilot test,four were collected during phase I of the pilot test, and four during phase II Soil gas/vapor samples were collected at one-hour intervals from the sample port of the extraction well to measure hydrocarbon concentrations in the extracted gas/vapor The samples were collected in 1,000 ml Tedlar bags vacuum chamber and an ' vacuum pump Samples were transported in a chilled container under chain-of-custody to Caltech Environmental Laboratories (CTEL), a California Department of Health Services (DHS)-certified laboratory I Each sample was analyzed within 72 hours for -,,,� ' vft - Total petroleum hydrocarbons quantified as gasoline (TPH-g), Q ml Benzene, toluene, ethylbenzene, and total xylenes (BTEX), methyl tertiary butyl ether -�, ' (MTBE),t-butyl alcohol(TBA),diisopropyl ether(DIPS),ethyl-t-butyl-ether(ETBE),t-amyl ,. methyl ether (TAME), 1,2-Dichloroethane (1,2-DCA) and 1,2-Dibromoethane (EDB) in ,rH J accordance with EPA Methods 8260B S A ' Advanced GeoEnvironmental,Inc