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possible source of hydrocarbon contamination detected <br /> during the prepartion of contaminant countours developed as <br /> a result of the placement of soil borings during October of <br /> 1993 . A second trench was excavated along the western <br /> boundary of the site in an effort to ascertain whether <br /> contaminants had migrated onto contiguous property. <br /> Discrete soil samples were acquired from the boundaries of <br /> both trenches following the removal of a total of approxi- <br /> mately 40 cubic yards . Much of the soil excavated from the <br /> trench near the on-site building was discolored and <br /> malodorous- apparently as a result of fuel hydrocarbon <br /> contamination. Soil excavated from the trench near the <br /> western property boundary shown no evidence of <br /> contamination. Excavated soil was placed atop 6 mil <br /> polyethylene sheeting and covered with the sheeting . <br /> Soil samples were obtained at the direction of Ms . Mary <br /> Meays of the San Joquin County Public Health Services <br /> Agency Environmental Health Division (PHS/EHD) . Each <br /> sample was obtained from a consolidated block of soil <br /> brought to grade within the bucket of the backhoe bucket <br /> After removing the top few inches of soil from the portion <br /> of the bucket to be sampled, a 1 . 9 inch diameter by 6 . 0 <br /> inch long clean brass tube was driven into the soil until <br /> it was completely filled with material The tube was then <br /> withdrawn and its ends covered with aluminum foil , fitted <br /> with plastic caps, and sealed with duct tape . Each tube <br /> was then labeled and placed into an iced, insulated <br /> container for transportation to Priority Environmental Labs <br /> of Milpitas under chain of custody. Certified analyses <br /> were subsequently performed for Total Petroleum <br /> Hydrocarbonas as Diesel (TPH-D) using EPA Methods <br /> 3550/8015, Total Petroleum Hydrocarbons as Gasoline <br /> (TPH-G) , benzene, toluene, ethylbenzene, and total xylenes <br /> (BTEX) using EPA Methods 5030/8015-8020 , and Oil and Grease <br /> (TOG) using SM 5520 D&F The results of these analyses are <br /> summarized in the following table <br /> Table 4 <br /> Analytical Results of Soil Samples Acquired from <br /> Exploratory Trenches Excavated on February 22 , 1994 <br /> 275 Grant Line Road, Tracy, CA <br /> Sample Date <br /> & Depth of TPH-D TPH-G B T E X TOG <br /> Sample (ft) (ppm) (ppm) (ppm) (ppm) <br /> -- <br /> Bldg Tr/8 . 5 N .D. N .D. N. D. N D. N D N.D. 13 <br /> BT North/8 ' N.D. N.D N.D N.D. N.D. N .D. N. D. <br /> Page 9 <br />