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06/24/2002 15 42 2094671118 AGE STOCKTON PAGE 06 <br /> 31 January 2002 <br /> AGE-NC Pioject No 95-0128 <br /> Page 5 of 8 <br /> An intei cept of the no influence edge of the semi-loganthrmc plot of draw-down in observation wells <br /> versus distance from the extraction point equals 100 feet the distance commonly thought of as the <br /> radius of influence (,Appendix F) Utilizing the parameters noted above and site specific <br /> characteristics, AGE calculated that the extraction wells pumped at five gallons per n unute would <br /> have a capture zone extending five feet down gradient, eight feet in each cross gradient direction, <br /> expanding up to fifteen feet in each du ection perpendicular to the flow direction approximately <br /> seventy-five feet up gi adient fxorn the purnping well Figure 3 shows the calculated capture zone for <br /> well EW-1 Calculations are shown in.Appendix G <br /> 3 2 EXTRACTED WATER SAMPLING PROCEDURES <br /> Approximately 4,100 gallons of purged water wet a generated during the pump test During the puuw <br /> test, two sets of a grab samples wet a collected prior to discharge into the tank utilizing three 40-nal <br /> EPA-approved volatile organic analysis (VOA) vials containing 0 5 nil 18% hydrochloric acid as a <br /> sample preservative The samples were collected at 1 30 pm(5 hour interval) and at the terinmation <br /> of the test 7 00 pm(12 hour interval) <br /> . Following sample collection, each preserved sample was logged on a chain-of-custody form, placed <br /> rn a chilled container and transported to a California Department of Health Services(DHS)-certified <br /> labor atory for analysis for <br /> • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, <br /> respectively) by EPA Method 8015 Modified, and <br /> • Benzene, toluene, ethylbenzene and xylene(BTEX)and methyl-tertiary butyl ether(MTBE) <br /> by EPA Method 8020 <br /> 33 ANALYTICAL RESULTS OF EXTRACTED WATER <br /> The results of the laboratory analysis of the two extracted ground water samples included TPH-g <br /> ranging from 22,000 mica ograms per liter(gg/1) up to 26,000 µg11 BTEX compounds were detected <br /> at concentrations as high as 3,900 µg/l (benzene) Analytical results of samples are summarized on <br /> Table 3 The laboratory i eports (McCampbell Analytical Inc Lab z D 81657 to 81658), Quality <br /> Assurance and Quality Control data and chain-o# custody fonm ai a presented in Appendix H <br /> 3 4 PURGED GROUND WATER DISPOSAL <br /> On 31 October 2001, the ground water extracted during the pumping test was pumped from the <br /> Advanced GooEaYironmcntat Inc <br />