Laserfiche WebLink
Mr Jeff Wong <br /> Page 3 of 4 <br /> Ppb, respectively BTEX constituents were detected only in well MW2 at relatively low <br /> concentrations Only benzene (74 ppb) was present in concentrations exceeding Primary Maximum <br /> Contaminant Levels (MCLS) No sample was collected from well MW 1 due to the presence of free <br /> product <br /> MTBE was present in wells MW2, MW3, MW4, and MW5 at concentrations of 810 ppb, 4,400 ppb, <br /> 13,000 ppb, and 90 ppb, respectively No sample was collected from well MW 1 due to the presence of <br /> free product <br /> Tables 3 and 4 summarize groundwater analytical results Attachment C contains a copy of the <br /> laboratory report and chain-of-custody documentation Figures 3 and 4 present isoconcentration <br /> maps of MTBE and benzene, respectively, in shallow groundwater beneath the site Attachment D <br /> contains plots showing the concentrations of TPHg, benzene, and MTBE over time in all site wells <br /> 4.0 SAMPLING AND ANALYSIS OF FACILITY WELL <br /> A groundwater sample was collected from the facility well on September 10, 2003, concurrent with <br /> monitoring well sampling The sample from the facility well was collected from the sampling port <br /> prior to the water entering the sediment tank The sample was submitted to Argon Laboratories and <br /> analyzed for TPHg, BTEX, and oxygenated gasoline additives by EPA Methods 8015B, 8021 B, and <br /> 8260B, respectively The sample contained 6 6 ppb MTBE A confirmation re-run of the sample <br /> contained 2 4 ppb MTBE A copy of the laboratory report is included in Attachment C <br /> Based upon the initial sample results, Ground Zero collected split samples from the facility well on <br /> September 19, 2003 for analysis by separate laboratories The samples were analyzed for BTEX, <br /> oxygenated gasoline additives, and lead the scavengers EDB and 1,2-DCA using EPA Method <br /> 8260B by both Argon Laboratories and GeoAnalytical Laboratories, Inc The split samples <br /> contained MTBE at 8 2 ppb (Argon) and 4 8 ppb (GeoAnalytical) These results were immediately <br /> • reported to Mr Jeff Wong of the San Joaquin County Environmental Health Department (EHD) <br /> Copies of the laboratory reports of the split samples are included in Attachment E <br /> EHD requested the immediate re-sampling of the facility well On September 24, 2003 Ground <br /> Zero personnel re-sampled the facility well, which was observed by Mr Wong of EHD The sample <br /> was submitted to FGL Environmental for analysis of volatile organic constituents (VOCs), including <br /> MTBE by EPA Method 524 2 No MTBE or VOCs were detected in the sample The detection <br /> limit for MTBE was 3 ppb A copy of the laboratory report is included in Attachment E <br /> 5.0 ADDITIONAL SITE ACTIVITIES <br /> Site activities conducted during the fourth quarter of 2003 included the following <br /> 1 Installing, developing, and sampling shallow monitoring wells MW 10, MW 11, and MW 12, <br /> 2 Installing, developing, and sampling deeper zone monitoring wells MW13C and MW14B, <br /> G IGROUNDZEITULEBURGIReporls\QMR1200313QM2003 doc <br />