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2 2 SEWER LINE INVESTIGATION ' Montgomery Ward suspected that a broken sewer line may be the source of contamination in Boring B-6 On June 9, 1991, Pacific Pipeline Survey (PPS) was retained by Montgomery Ward to investigate the existence of a possible break in the sanitary sewer manhole, associated piping, and a clarifier which are located in close proximity to the ' former location of the gasoline USTs According to this investigation, about one foot of the sewer line was broken On September 12, 1991, representatives of Stone Brothers excavated a trench around the suspected broken sewer line to an approximate depth of 2 5 feet bgs (see Figure 2) Two slant borings were drilled around the sewer line using a hand auger Commencing ' near the base of the clay pipe (2 5 feet bgs), Boring SB-1 was hand augered to a calculated vertical depth of 5 75 feet bgs Two soil samples (SS-1 and SS-2) were collected from SB-1 at a depth of 3 5 and 5 5 bgs, respectively Boring SB-2 was hand augered to an estimated depth of 4.75 feet bgs in the sidewall of the excavation and a soil sample (SS-3) was collected at the termination depth. The boring was terminated approximately beneath a ' second sewer line that extends west of the manhole ' No TPH were detected in any of the three soil samples associated with the sewer line However, minor concentrations of BTXE, bromoform, carbon disulfide, chloroform, tetrachloroethene, trichloroethene, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane and 1,1,2-trichloroethane were detected in the soil samples (see EAI, 1991A). 2 3 PRODUCT LINE/FUEL ISLAND INVESTIGATION In June 1986, after the gasoline USTs were removed, the underground piping associated with the USTs was rinsed, stubbed back, capped and left in place pursuant to approval from the County On September 12 and 13, 1991, 12 slant borings were hand augered to depths of approximately four feet bgs Soil samples PL-1 to PL-12 were collected along the product lines which extend between the former fuel islands and the former UST locations (see Figure 2). No detectable concentrations of TPH were present in any soil samples, except for soil sample PL-7. TPH (844 ppm), toluene (0.95 gm) ethylbenzene (0 65 ppm) andxylenes (9 SS ppm) were detected in soil sample PL-74-4 5'. Benzene was not detected in soil sample PL-7 (see EAI, 1991) In July 1992, EAI drilled and sampled two additional borings (Borings B-9 and B-10) in the vicinity of the fuel islands on the east and west sides of PL-7 (see Figure 2). Elevated concentrations of TPH (1,200 to 3,490 ppm) were detected from sam les B-9 @ 15' through B-9 @ 30'. Total recoverable petroleum hydrocarbons (TRPH� were detected t only in sample B-9 @ 20' at 563 ppm No benzene was detected in any of the samples tested. Elevated concentrations of toluene, xylenes and ethylbenzene were also detected in inose samples whlc11 11 U elevated i'gH ConC'el7trdtloll5. The total lead %oilceiltratii3i7s varied from 5.72 to 13 4 ppm No soluble lead was detected in the sample (B-10 @ 10) which contained the highest total lead concentration The carbon chain breakdown for the hydrocarbons present in sample B-9 @ 20' indicate a hydrocarbon range from C8 to C18, with-the maximum-occurring-in the C9-C10 range-(see EAI; 1992) - -- - - - - - Project No. 1232 3 ENVIRONMENTAL AUDIT,INC®