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r a — N ► x Site Background Information : Quick N Save # 1 Page 7 of 9 Laboratory analysis of extracted water during the pumping test detected elevated concentrations of TPH-g , BTEX, MTBE , and 1 , 2-DCA in both samples submitted for analysis . Concentrations were as high as 61 , 000 pg/I TPH-g , 9 ,900 pg/I benzene , 23 , 000 pg/I toluene , 2 , 500 pg/I ethylbenzene , 18 , 200 pg/I xylenes, 220 pg/I MTBE , and 230 pg/I 1 ,2-DCA. All concentrations detected were significantly above the respective maximum i . contaminant level (MCL) for each contaminant. Soil Vapor Extraction Pilot Test - August 2005 On 23 August 2005 , a SVE pilot test was conducted at the site . The pilot test operated for approximately 7 hours and was terminated due to stabilization . An induced vacuum potential was applied to the casing of vapor well VW-3 . The vacuum-induced pressure reduction was monitored at surrounding observation points (VW- 1 , VW-2 , VW-4 , and MW- 2) 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 : Microtip model 1000 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 of the SVE unit were measured at 0 .5-hour intervals and logged on field sheets. The SVE unit was operated at approximately 2 ,500 RPMs for the eight- hour test, with a flow rate measured between 30 scfm (standard cubic feet per minute) and 36 scfm . OV readings ranged from 1158 to 1401 ppm . Induced vacuum measured at the extraction well (VW-3 ) was a constant 94 inches of water. Based upon an effective vacuum potential of 0. 1 inches of water, the calculated effective radius of influence of SVE at the site will be approximately 28 feet. TPH-g was detected in the soil vapor samples at concentrations ranging from 8,700 pg/I to 10 , 000 pg/I . Benzene , toluene, ethylbenzene and total xylenes were detected in the gas/vapor samples at concentrations as high as 55 pg/I of benzene , 170 pg/I of toluene, 87 pg/I of ethylbenzene , and 310 tag/I of total xylenes . MTBE was detected at concentrations ranging between 120 lag/I and 160 pg/I . Dual Phase Extraction Pilot Test - November 2009 A DPE pilot test consisted of simultaneously extracting ground water and soil-vapor from two on-site dual phase extraction wells (EW-1 and MW-2 ) took place in November 2009 . _ Background static water level from well EW-1 was measured at 26 .45 feet bsg and from well MW-2 at 26 .23 feet bsg ; after a short duration (approximately 5 minutes), ground water level was successfully sustained below the DPE stinger inlet at 54 feet bsg in well EW- 1 and 45 feet bsg in well MW-2 . Ground water extracted from wells EW- 1 and MW-2 ._ Advanced GeoEnvironmental, Inc.