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<br /> DATE November 17 2003
<br /> QUARTERLY GROUNDWATER MONITORING REPORT--THIRD QUARTER 2003
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<br /> -Facility Former E-Z Serve No 140$78 SiteAddress 1012 West Yosemite Avenue,Manteca,California
<br /> Responsible P /Contact Person RPMS-CA/Jeff Burke,Pro ect Manager
<br /> Consulting Co /Contact Person ATC Associates Inc /Todd Hafner,Project Manager 209 579-2221
<br /> ATC Project No 54 25827 2513
<br /> -RegulatoryAgency/File No County of San Joaquin,Environmental Health Division/1452
<br /> ' WORK PERFORMED THIS QUARTER [July 1,2003—September 30,2003]
<br /> I Performed third quarter groundwater monitoring and sampling
<br /> 2 Prepared third quarter groundwater monitoring report
<br /> ' WORK PROPOSED FOR NEXT QUARTER [October 1,2003—December 31,2003]
<br /> I Perform fourth quarter groundwater monitoring and sampling
<br /> 2 Submit fourth quarter groundwater monitoring report
<br /> Current Phase of Project Assessment Assessment,Remediation,etc
<br /> Frinquency of Sampling uarterl (Quarterly, etc
<br /> Frequency of Monitoring Quarterly (Monthly,etc
<br /> Liquid Phase Hydrocarbons Present On Site No Yes/No
<br /> Cumulative PSH Recovered to Date Unknown Gallons
<br /> PSH Recovered This Quarter None Gallons
<br /> Pure Water Removed This uarter None (Gallons)
<br /> Permits for Discharge None MPES,POTW,etc
<br /> Current Remediation Techni ues None SVES,PSH Recovery)
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<br /> Approximate Depth to Groundwater 20 38 to 22 02 (Measured Feet
<br /> Groundwater Gradient 0 0026 ft/ft Ma itude
<br /> { Groundwater Flow Direction North Direction
<br /> Discussion On August 25, 2003, ATC Associates Inc (ATC) personnel gauged eight groundwater monitoring wells (Figures 1 and 2)
<br /> ' Depth to groundwater ranged between 20 38 (MW-7)to 22 02 (MW-3)feet below ground surface(bgs) The calculated hydraulic gradient
<br /> is approximately 0 0026 f4/ft towards the north(Figure 2) No measurable phase-separated hydrocarbons(PSH)were recorded during this
<br /> f i monitoring event Groundwater elevations and contours are illustrated on Figure 2 and groundwater monitoring data are presented in Table
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<br /> On August 25, 2003, ATC collected groundwater samples from monitoring wells MW-1 using through MW-8 the procedures
<br /> g g sampling P
<br /> described in Appendix A Field logs are also included in Appendix A Groundwater samples collected were analyzed for total petroleum
<br /> hydrocarbons quantified as gasoline(TPHg) by EPA Method 8015B, benzene, toluene, ethylbenzene, and total xylenes(BTEX) by EPA
<br /> Method 80218, as well as fuel oxygenates and additives methyl tert-butyl ether(MTBE), di-isopropyl ether(RIPE), ethyl tert-butyl ether
<br /> + r (ETBE), tert-amyl methyl ether(TAME), tert-butyl alcohol (TBA), I,2-dichloroethane(1,2-DCA), and 1,2-dibromoethane (EDB)by EPA
<br /> Method 8260B TPHg concentrations above the laboratory-reported method detection limit of 50 micrograms per liter(pg/L)were reported
<br /> in three of the eight wells sampled in the third quarter The highest TPHg concentration was detected in the sample collected from MW-5 at
<br /> a concentration of 400 pg/L Benzene was detected at concentrations of 2 4 pg/L, 0 7 jig/L, and 3 2 µgJL in the groundwater samples
<br /> collected from MW-I, MW-2 and MW-5, respectively MTBE was detected at a concentration of 5 5 µg/L in the groundwater sample
<br /> collected from MW-6 DIPE, ETRE, TAME, TBA, 1,2-DCA, and EDB concentrations were reported below their respective laboratory
<br /> reporting limits in all of samples collected from the eight monitoring wells TPHg, benzene, and MTBE concentrations are illustrated on
<br /> r Figure 2 and historic groundwater analytical'results are presented in Table I Groundwater analytical results for fuel oxygenates and
<br /> additives are presented in Table 2 Hydrographs of groundwater elevations and analytical data are attached in Appendix B and laboratory
<br /> analytical results and chain-of-custody documentation are attached in Appendix C
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<br /> Recommendations Recent historical groundwater quality data indicate impact to groundwater is minor None of the requested analytes '
<br /> were detected at or above regulatory levels in any of the groundwater samples collected on August 25, 2003, with the exception of the
<br /> groundwater samples collected from MW-1 and MW-5 Benzene was detected in these samples at concentrations of 2 4 gg/L and 3 2 µg/L' I'
<br /> respectively Historical groundwater quality data indicate trends of reduced petroleum hydrocarbon concentrations in groundwater samples I'
<br /> collected from the monitoring wells,which suggests natural attenuation has occurred and is continuing Petroleum hydrocarbon constituents
<br /> have not been detected in samples collected from MW-3, MW-4, MW-7 and MW-8 for at least a couple of years ATC recommends the
<br /> site be considered for closure
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<br /> I � 3rdQuarler 2003 Groundwater Report EZ SERVE 4100878 ATC Associates Inc `1
<br /> 'S IEnviromentah25827125 MantecalReports1EZ878(2003 Q3 GW Rpt)doe ATC Prosect No 54259272513 '
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