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1 <br />' 24 July 2002 <br /> AGE-NC Project No 01-0827 <br />' Page 2 of 6 <br />' Soil-vapor samples were collected to document trends in concentrations of hydrocarbon vapor in the <br /> soil-vapor extracted by the SVE network and to determine the treatment system hydrocarbon <br /> destruction rate Soil-vapor samples from the influent and effluent streams were collected in Tedlar <br />' vapor bags on 12 March, 16 April, 13 May and 11 June 2002 The samples were labeled,placed in <br /> pre-chilled coolers and transported under chain-of-custody to McCampbell Analytical, Inc (MAI), <br /> a State of California Department of Health Services (DHS)-certified analytical laboratory The <br />' samples were analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in <br />' accordance with EPA Method 8015 Modified and <br /> • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and methyl. tertiary butyl ether <br /> (MTBE) in accordance with EPA Method 8020, <br />' The results of the laboratory analysis are summarized in Table 2 <br />' 2 2 WELL MONITORING AND EVACUATIONS <br />' . On 03 May 2002, a Sohnst water level meter was used to measure the depth to ground water in <br /> ground water monitoring wells MW-1 through MW-5 and vapor wells VW-1, VW-2d, VW-3 and <br /> VW-5d The ground water elevations and gradient were determined from this data (Table 1) <br /> tAfter water levels were gauged, a dedicated disposable bailer was used to purge wells monitoring <br /> wells MW-1, MW-3 and MW-5 and vapor wells VW-1,VW-2d, VW-3 and VW-5d of a minimum <br />' of three casing-water volumes (approximately 4 to 18 gallons) of ground water Temperature, pH, <br /> and conductivity were measured at regular intervals during purging using an Oakton model water <br /> analyzer Purged water was stored on-site in 55-gallon drums The field data sheets are included in <br />' Appendix A <br />' 23 GROUND WATER SAMPLE COLLECTION <br />' Water samples were collected from each monitoring well using new disposable bailers after allowing <br /> the wells to achieve a minimum 80% recovery of the pre-purge water volume Each sample was <br /> transferred into three 40-m1 EPA-approved volatile organic analysis (VOA) vials and one 1-liter <br />' amber bottle Samples were stored in a chilled container and transported under chain-of-custody to <br /> Precision EnviroTech (PET) of Stockton, a DHS-certified analytical laboratory Each sample was <br /> analyzed for <br />' TPH-g and TPH-d in accordance with EPA Method 8015 Modified, <br />' Advanced GeoEnvironmentai,Inc <br /> I <br />