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' 19 November 1997 <br /> AGE-NC Project No 95-0143 <br />' Page 2 of 4 <br />' container,to McCampbell Analytical,Inc (MAI)in Pacheco, California The samples were analyzed <br /> for total petroleum hydrocarbons quantified as gasoline (TPH-g) by EPA Method 5030/8015 <br /> modified, for volatile aromatic compounds (benzene, toluene, ethylbenzene and xylenes BTE&X) <br />' in accordance with EPA Method 602, and for volatile organic compounds with oxygenated volatile <br /> organics, in accordance with EPA Method 8260 <br />' 3.0. FINDINGS <br />' 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT <br />' The relative elevation of ground water in each well was calculated by subtracting the depth to water <br /> from the surveyed casing elevation(Table 1) Ground water elevation decreased an average of 0 72 <br /> feet between August and November 1997 Ground water was approximately six feet above the <br /> screened interval in MW-3 and MW-6 and approximately three feet above the screened interval in <br /> MW-6 and MW-7 Ground water was within the screened interval for the remaining wells at the site <br /> The approximate hydraulic gradient was calculated to be 0 0043 ft/ft with a northerly flow direction <br /> north of the site, similar to the gradient measured at the Madison site However,a shallower gradient <br /> of 0 0014 ft/ft was measured on the subject property with a northeasterly flow direction Relative <br /> ground water elevation contours for the November 1997 monitoring event are illustrated in Figure <br /> I3 <br /> 3 2 ANALYTICAL RESULTS OF WATER SAMPLES <br /> During the November 1997 monitoring event,TPH-g was detected at concentrations of 200,000 parts <br /> per billion(ppb, reported as micrograms per liter), 2,600 ppb, 2,300 ppb, 42,000 ppb and 76 ppb, <br /> in samples from MW-3,MW-6,MW-7,MW-9 and MW-14,respectively BTE&X compounds were <br /> detected in samples from the same wells at concentrations as high as 55,000 ppb (toluene in sample <br /> from MW-3) <br /> Di-isopropyl ether (DIPE) and 1,2-Dichloroethane (1,2-DCA) were detected in MW-14 at <br /> concentrations of 5 6 ppb and 22 ppb, respectively BTE&X were detected by EPA Method 8260 <br /> at concentrations similar to EPA Method 602 Eight additional constituents without established <br />' drinking water standards were detected by EPA Method 8260 in samples collected during the <br /> November 1997 monitoring event(Table 3) <br /> IPetroleum hydrocarbons were not detected in the samples collected from MW-10, MW-15, MW-16 <br /> . or MW-17 Free product was not encountered in any of the wells on the site Analytical results of <br /> ground water samples are summarized on Tables 2 and 3 The Iaboratory report (MAI Laboratory <br /> Advanced GeoEnviron mental,Inc <br />