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Stantec PHASE II ENVIRONMENTAL SITE ASSESSMENT REPORT 3.0 Laboratory Analytical Results and Screening Soil and soil vapor samples collected during this project were transported to BC Labs under standard COC procedures. Soil vapor samples were analyzed from the 6 soil vapor sampling points and the duplicate sample. Selected soil samples (SS-1, SS-2, SS-5, and SS-6) were chosen for chemical analyses based on locations of suspected historical features/existing subsurface impacts and the soil vapor analytical results. Soil samples SS-3 and SS-4 were submitted to BC Labs and placed on hold pending the soil vapor analyses. No additional soil vapor analyses were required. Copies of the certified laboratory analytical reports and COC documentation are provided in Appendix B. 3.1 SOIL VAPOR ANALYTICAL RESULTS To facilitate the collection of soil vapor samples, each soil vapor well was purged of a calculated three well volumes of soil vapor using a gas tight syringe. The soil vapor points were purged at a rate of approximately 100 to 200 ml/min. Upon purging the soil vapor well, the stopcock on the tubing was closed. SUMMA® canisters were laboratory-supplied for this project however; two of the SUMMA® canisters were defective and could not be used for sample collection. The laboratory-supplied tedlar bags were used as a backup for soil vapor samples SV-5 primary and duplicate sample. The SUMMA® canisters/tedlar bags were filled with the soil vapor, sealed, and labeled with the soil vapor point identification, date and time, and submitted to BC Labs under COC for analysis of VOCs by EPA Test Method TO-15. A total of 6 primary and 1 duplicate soil vapor samples were collected at a depth of 5 feet bgs from soil vapor wells SV-1 through SV-6 on March 11, 2011. The laboratory analytical reports and COC documentation are presented in Appendix B. Table 1 provides a summary of the analytical results for 79 VOC constituents. The following VOCs were detected in one or more samples: acetone, carbon disulfide, ethanol, ethylbenzene, 1-ethyl-4-methylbenzene, n- heptane, isopropyl alcohol, methylene chloride, tetrachloroethene, toluene, 1,2,4- trimethylbenzene, 1,3,5-trimethylbenzene, p- & m-xylenes, o-xylenes, total xylenes, TPH gasoline, and total gaseous non methane organics (TGNMO). Shallow soil vapor concentrations were screened against commercial/industrial California Human Health Screening Levels (CHHSLs) and commercial/industrial San Francisco Regional Water Quality Control Board (RWQCB) Environmental Screening Levels (ESLs). ESLs are commonly used for site screening purposes by the RWQCB. VOC analytical results were not detected above their corresponding CHHSLs and ESLs in the soil vapor samples analyzed, except for tetrachloroethene (PCE) in sample SV-2. PCE was reported at a concentration of 1,400 micrograms per cubic meter (pg/m3) in the soil vapor sample SV-2 collected in the southwest comer of the northern warehouse. The CHHSL and ESL shallow soil gas screening levels for PCE in commercial and industrial soils are 1,400 and 603 pg/m3, respectively. i:\projects\calpine\lodikeport\lodi.svrpt.dou 3.1