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IM <br /> hydrocarbon encountered in the samples obtained from boring B-5. <br /> Elevated concen' rations of TPH, toluene, xylenes, and <br /> ethylbenzene were detected in seven of the ten samples obtained <br /> at depths from six to 50 feet bgs in boring B-6. No organic <br /> lead was detected in any of the Samples tested, and the TPH <br /> concentration in the sample collected at 50 feet bgs was 7. 3 <br /> ppm. The concentrations of total and soluble lead were well <br /> below the standards contained in Title 22. <br /> For specifics regarding the activities completed at the Site <br /> by EAI, see EA11s report titled "Phase II Site Assessment Report <br /> 5400 Pacific Avenue, Stockton (Site Code 2163) ,11 dated May 20, <br /> 1991. <br /> Ward suspected that a broken sewer line may be the source of <br /> contamination in boring B-6. On June 9, 1991, Pacific Pipeline <br /> Survey (PPS) was retained by Ward to investigate the existence <br /> of a possible break in the sanitary sewer manhole, associated <br /> piping, and a clarifier which are located in close proximity to <br /> the former location of the underground storage tanks (USTs) . <br /> According to this investigation, about one foot of the sewer <br /> line was broken. <br /> 1.2 PURPOSE OF THIS INVESTIGATION <br /> Ward requested that Stone Brothers excavate the soil cover <br /> at the location of the suspected broken sewer line identified by <br /> PFS on September 12, ,991, in order to repair the damage. EAI <br /> was retained by Ward to collect soil samples from beneath the <br /> suspected broken sewer line, and from beneath the product Lines <br /> associated with the USTs formerly located on the Site. This <br /> report presents the findings obtained from completing the above <br /> described investigations, and the additional work proposed to <br /> attempt to define the extent of contamination encountered by the <br /> sewer line and product lines associated W4.th the USTs formerly <br /> located on the Site. <br /> 2.0 FIELD INVESTIGATION <br /> 2.1 INVESTIGATION OF SEWER LINE <br /> On September 12, 1991, representatives of Stone Brothers <br /> used shovels to hand excavate around the suspected broken sewer <br /> line (see Figure 3) . A trench around the sewer line was <br /> excavated to an approximate depth of 2.5 feet bgs. This <br /> excavation exposed a red 4-inch clay sewer pipe that extended <br /> north from a manhole approximately 3 feet to where it was <br /> coupled with a 4-inch cast iron sewer pipe. The cast iron pipe <br /> extended northward under the Ward building. From the manhole <br /> -north,- the -clay pipe was- otally encased in concrete for a <br /> Project No. 1232 -2- <br /> F,,%,VIROAF1111.�'AITA L AUDIT,IA7C., <br />