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I }, 30 October 2003 AGE-NC Project No. 98-0440 Page 3 of 4.. 3.2..* ANALYTICAL RESULTS OF GROUND WATER-SAMPLES :' �• TPH-g•was detected in the water samples collected from monitoring;wells MW-2,and MW-5 at concentrations of 450 µg/land 110 pg/l, respectively.TPH-d was detected•-in the sample.collected' '• from.monitoring well MW-2:ata concentration of 230pg/l. Benzene was detected in the water`samples collected from wells MW72; MW-5,'MW-6 and MW-7 t at concentrations ranging from 82 l W-2 to 490 l(MW-6). One or more BTEX compounds were detected in the same samples at concentrations as,high as 20 'pg/1 benzene, 2.8.pg/1 toluene, 42 gg/l ethylbenzene and 6.9 µg/1 total xylenes. No other analytes were detected at or 'above. . , ' laboratory reporting limits iri the water samples collected from the monitoring wells and domestic water well on-site. A ma showin the a roximate extent p. g pp of:dissolved benzene is ',presented iii ' ;Figure 5.- Current :Current and previous analytical results are,summarized on:Table 2. The laboratoryreport (MAI- ; Work Order Number 0309362), QA/QC,'report and chain-of-custody 46rm are included Appendix B. 4.0. SUMMARY AND CONCLUSIONS Based on the data collected during this monitoring period, AGE concludes:' • Ground water elevations.at the SiteL ranged from. 27.56 feet above MSL iii well MW-8 to, 28.41 feet above MSL in well MW-1. Ground watenelevations increased an average of 1:5 feet between the June 2003 and September 2003 monitoring events. Ground water levels were within the screened intervals of all the monitoring wells on The ground water at the site was inferred -to' be. flowing toward the north•under'ai. average ;gradierit.'of ; 0.005 feet/feet which is consistent with -the flow direction'determined during previous 1. monitoring events. • The highest concentration of dissolved,hydrocarbons quantified as TPH-g and BTEX . . compounds extends northeast from USTs No`' 4 'and 5.' Dissolved .hydrocarbons were ' encountered in 'tlie.down-gradient direction. from the former-UST's in samples 'from monitoringwells MW-2' MW-5;MW-6 and -7..The concentrations-ofbenzene detected in the water, samples collected from wells MW-2 and' 1VIW 5- were;above the'; State of California maximum contaminant level (MCL).of 1.0 pg/l for benzene in drinking water. A map showing the approximate extent of dissolved benzene is presented in•Figure'5. ' . The lateral extent of petroleum hydrocarbon-impacted ground water has been defined_ •Advanced GeoEnvironamental,Inc.-