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Pre-Tank Relining Site Assessment Report 2 The Southland Corporation 4501 North Pershing Avenue Stockton California February 28, 1997 Using a truck-mounted drill and direct push techniques, four discrete soil samples were collected from each of the angled soil borings at a vertical depth of 15 BGS feet beneath the three 10,000-gallon USTs at the site (Figure 2). A total of four additional soil samples were collected from the three vertical borings at depths of 17 and 22 feet BGS. Angled soil borings were drilled at 25 degrees from vertical. The depth of sample collection in each of the angled borings shown on the sample numbers and listed in Table 2 has been corrected to reflect true vertical depth. Each core was collected in a 2-foot-long by 1.25-inch-outside-diameter stainless steel sampling barrel lined with 1-inch-diameter by 6-inch-long brass tube inserts. After being driven to the required sampling depth, the lead drive point of the core sampler was released and the sample barrel was pushed an additional two feet to collect the soil sample. Following sample collection,the sampling barrel and drive rods were removed from the probe hole and the sleeves containing the soil samples were removed from the sampling barrel and used for soil descriptions. One sample sleeve from each sample location was retained for laboratory analysis. The drive rods and tools were triple rinsed with Alconox detergent and distilled water between bore holes, and all sampling equipment was cleaned between each sampling interval to reduce the potential for cross-contamination. The soil from the cores was screened for hydrocarbon vapors using a photoionization detector (PID). Soil was logged using the Unified Soil Classification System by a Fluor Daniel GTI field geologist working under the supervision of a California registered geologist (Appendix A). One 6-inch-long sleeve was collected from the 2-foot-long sample tube at each sampling interval,sealed with tape, labeled and placed on ice in an insulated container for transport under chain-of-custody manifest to Western Environmental Science & Technology(WEST) in Davis, California for analysis. Field notes are included as Appendix B. A total of eight soil samples were submitted for laboratory analysis for benzene,toluene, ethylbenzene and total xylenes (BTEX), methyl-tert-butyl-ether(MTBE), and total petroleum hydrocarbons-as-gasoline (TPH-G) using EPA methods 8020/modified 8015. To confirm the presence of MTBE reported using EPA method 8020, one soil sample was analyzed using EPA method 8260. One sample from each of the six borings drilled beneath and adjacent to the USTs was additionally analyzed for total lead by SW-846 method 6010. Following collection of soil samples, each soil boring was grouted back to surface grade with neat cement. 2.3 Groundwater Sampling Methods Following completion of the borings,groundwater samples were collected from borings GP3, GP4, and GP7 using a stainless steel bailer,then decanted into 40-milliliter glass vials (treated with hydrochloric acid to preserve the samples)and a 1-liter amber bottle. During sampling of GP4, located immediately east of the tank pit, a sheen was noted on the bailed water. The samples were sealed using Teflon&septum caps, labeled, placed on ice in an insulated container, and transported under chain-of-custody manifest to WEST Laboratories. The groundwater samples were analyzed for BTEX, MTBE, and TPH-G, using EPA methods 0472ASMT.RPT(SMML56) FLUOR DANIEL GTI