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Canepa s Car Wash
<br /> 6230 Pacific Avenue,Stockton,CA
<br /> First Quarter Groundwater Monitoring Report,January 2005
<br /> Page 4 of 8
<br /> . LABORATORY ANALYTICAL RESULTS
<br /> Groundwater samples collected from the monitoring wells and SV4 were analyzed for total petroleum
<br /> hydrocarbons quantified as gasoline (TPH-G) by EPA Method 8015M and benzene, toluene, ethyl
<br /> benzene, and total xylenes (BTEX) and selected gasoline oxygenates/additives by EPA Method 8260B by
<br /> Excelchem Environmental Labs of Roseville, California (Excelchem) The selected oxygenates/additives
<br /> included MTBE, ethanol (EtOH), tertiary-butanol (TBA), dl-isopropyl ether (DIPE), ethyl tert-butyl ether
<br /> (ETBE), tert-amyl methyl ether(TAME), 1,2-dichloroethane (1,2-DCA), and 1,2-dibromoethane (EDB)
<br /> The current groundwater sample analytical results (Table 3, below) are generally consistent with the
<br /> historic results with the exception of MW-1 (Table A, Attachment C) None of the contaminants of
<br /> concern were detected at or above the laboratory reported detection limits in monitoring wells MW-4,
<br /> MW-9, and MW-12D
<br /> The laboratory analytical results of the sample collected from MW-3 indicate that the MTBE
<br /> concentration decreased relative to the October 2004 sample (Figure 6, Attachment A) Contaminant
<br /> concentrations in the sample collected from MW-1 increased significantly relative to the July 2004
<br /> monitoring event and are generally at the highest concentrations since June 1995 This increase is
<br /> anticipated as the groundwater extraction draws the center of the contaminant plume toward it Benzene
<br /> and MTBE iso-concentration contour maps are included as Figures 4 and 5, respectively, Attachment A
<br /> Laboratory certificates of analyses and chain of custody records are included in Attachment F
<br /> Table 3
<br /> Groundwater Sample Laboratory Analytical Results (January 21 and 24, 2005)
<br /> Constituent Benzene Toluene Ethyl Total TPH-G MTBE Other Gasoline
<br /> Benzene Xylenes
<br /> MCL 1 pg/L 150 pg/L 700 pg/L 1 750 pg/L 13 pg/L Oxygenates/Additives
<br /> Analytical Method—+ 8260B 8260B 8260B 8260B 8015m 8260B 8260E
<br /> Reporting Limits--+ 0 5 gulf- 0 5 pg/L 0 5 gg/L 1 0 pg/L 005 05 05-20
<br /> Sample I D mg/L pg/L p�
<br /> 1707-MWI-1121105 8,400 3,800 13 3,280 30 7,200 < 1 0-<40
<br /> 1707-MW2-1/21/05 8,300 1,100 2,500 4,370 37 <1 0 < 1 0-<40
<br /> 1707-MW3-1121105 13 <1 0 <10 <3 0 0 54* 1,500 82(1,2-DCA)
<br /> 1707-MW4-1/21/05 <0 5 <0 5 <0 5 <1 5 <0 05 <0 5 <0 5 -<20
<br /> 1707-MW9-1/21/05 <0 5 <0 5 <0 5 <1 5 <0 05 <0 5 <0 5 -<20
<br /> 1707-MW 11-1/21/05 320 84 2 4 173 0 78* 550 <0 5-<20
<br /> 1707-MW 12D-1/21105 <0 5 <0 5 <0 5 <1 5 <0 OS <0 5 <0 5-<20
<br /> <5vv-<2v,unn
<br /> 32
<br /> 1707D-SVE4-1/24105 77,000 68,000 4,900 24,000 360 0,000
<br /> VU
<br /> Bold analytical data exceed California MCL(Maximum Contaminant Level)
<br /> *= Me sample chromatogram does not match the standard gasoline chromatogram
<br /> Units Analytical
<br /> mg/L=milligrams per liter=parts per milhon(ppm) B T E X=benzene toluene,ethyl benzene,total xylenes
<br /> pg/L=micrograms per liter=parts per billion(ppb) TPH-G=total petroleum hydrocarbons quantified as gasoline
<br /> Gasoline oxygenates/additives= methyl tertiary-butyl ether(MTBE),ethanol,
<br /> • tertiary-butanol (TBA), di-isopropyl ether (RIPE), ethyl tertiary butyl ether
<br /> (ETBE), tertiary-amyl methyl ether (TAME) 1,2-drehloroethane (1,2-RCA),
<br /> 1,2-dibromoethane(1,2-EDB)
<br /> �� CONDOR
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