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h <br /> 1 ' <br /> i27 February 2003 <br /> ' AGE-NC Project No 95-0103 <br /> Page 2 of 7 <br /> ' under permit during the fourth quarter 2002 (T�:ble 4) The ground water treatment system operates <br /> on a batch basis, with a daily total of 14,400 gallons Once the 2,000-gallon holding tank fills, <br /> approximately 3,500 gallons of extracted ground water is created and discharged The discharge of <br /> t treated water(effluent)to the City of Stocktonwas adjusted ata flow rate of approximately 10 GPM <br /> ' 2 2 GROUND WATER TREATMENT MONITORING PROCEDURES <br /> ' In order to verify and quantify the mass of contamination from each extraction well and to comply <br /> with the requirements of the City of Stockton discharge permit, monthly monitoring and sampling of <br /> influent and effluent ground water samples were performed Grab ground water samples wei e <br /> collected on 19 September and 15 October from extraction wells EW-1, EW-2 and EW-3 and the <br /> effluent port of the treatment system, and on 10 December and 27 December 2002 from the influent <br /> and effluent sampling ports of the treatment system In addition, grab ground water samples wei e <br /> collected from the effluent port on 11 November 2002 and the influent port on 25 November 2002 <br /> . <br /> Influent sampl es were collected inlaboratory-supplied40-ml EPA-approved volatileorganic analysis <br /> (VOA) vials containing 0 5 ml 18% hydrochloric acid as a preservative Effluent samples wei e <br /> collected in the (VOA) vials, 1-liter amber bottles without preservative and 500-rrulliliter plastic <br /> bottles without preservative Care was taken to ensure that visibleair bubbles were not present in the <br /> ' vials after fillingand capping Water sample containers were labeled with the sample designation, <br /> date, time, and sampler's init.als <br /> rThe samples collected were logged on a chain-of-custody form, placed in a chilled container and <br /> transported to McCampbell Analytical Inc (MAI), a California Department of Health Services <br /> ' (DHS)-certified laboratory, foranalysis Except forthe 27 December2002 samples,allsampleswete <br /> analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) by EPA Method 8015 <br /> Modified, and <br /> • Benzene,toluene,ethyl benzene andxylene(BTEX)and methyl-tertiary butyl ether(MTBE) <br /> by EPA Methods 8020 or 8260 <br /> In addition,the effluent samples were analyzed for pH in accordance with EPA Method 150 1, and <br /> the influent and effluent samples collected on 27 December 2002 were analyzed only for total <br /> petroleum hydrocarbons quantified as diesel (TPH-d)�by EPA Method 8015 Modified <br /> Advanced Gee E+nvirennientai,Inc <br /> 1 <br />