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eedopeW envbnnrn4�. 2 Site Background with a dispenser pump and nozzle for fueling the fire engines is located just northwest of the fire house. The southern portion of the property is currently vacant but appears to have been graded or tilled in the past few months as there are tire nits throughout the site. There are no buildings in the southern portion of the site and the majority of the site is overgrown by vegetation. 2.4.2 Previous Investigations on the Subject Property According to the E&E Draft Phase I ESA(E&E 2010),multiple letters and documents from the San Joaquin County Environmental Health Department(SJCEHD) were reviewed regarding the removal and sampling of the two former USTs that were located on site,which are discussed individually below: 500 gallan diesel UST:A 500-gallon diesel UST,which was located approximately 10 feet east of the northeast comer of the fire station,was removed on June 28, 1993,under permit and inspection by the SJCEHD. Two soil samples were collected for analysis, one in the stockpile of removed soil and one 2 feet below the removed UST at a depth of approximately 7 feet bgs. A slight odor was noted by the SJCEHD inspector in stockpiled material;however,no odor or discoloration was noted in the tank pit. Both soil samples were analyzed for volatile organic compounds(VOCs); total petroleum hydrocarbons(TPH) as gasoline(TPH-g),diesel(TPH-d), and motor oil(TPH-mo); benzene, toluene, ethylbenzene,and xylenes(BTEX); and total lead. The analytical results of the tank pit soil sample indicated only a concentration of total lead(17 milligrams per kilogram [mg/kg])above the laboratory reporting limit. The analytical results of the stockpile soil sample indicated concentrations of TPH-d(190 mg/kg),TPH-mo (11 mg/kg), TPH-g(1.1 mg/kg), and total lead(15 mg/kg)above the laboratory reporting limit. Based upon the low concentration of contaminants in the tank pit sample and the removal of the stockpile material from the site, the SJCEHD issued a case closure letter for this diesel UST, dated June 10, 1994. 550 gallon gasoline UST: A 550-gallon gasoline UST,which was located approximately 10 feet southeast of the southwest corner of the fire station,was removed on June 28, 1989, under permit and inspection by the SJCEHD. One soil sample was collected for analysis at the fill end of the UST in the tank pit, approximately 8 feet bgs. A slight odor was noted by the SJCEHD inspector of the soil in the tank pit. The soil sample was analyzed for VOCs,TPH-g, BTEX, and total lead.The analytical results of the tank pit soil sample indicated concentrations of TPH-g (190 mg/kg),toluene(3.7 mg/kg), xylenes(110 mg/kg), ethylbenzene(4.1 mg/kg), and total lead (15 mg/kg)above the laboratory reporting limit. At the request of the SJCEHD, four direct push borings were advanced on site by Twinning Labs in the vicinity of the removed gasoline UST on December 20, 1996. Soil samples and one groundwater sample were collected for analysis. Soil and groundwater samples at one of the boring locations contained detectable concentrations of petroleum hydrocarbons. Further investigation was conducted on site at the request of the SJCEHD on July 20, 1998, when one monitoring well(MW-1)was installed by Advanced GeoAnalytical at the location of the former gasoline UST. Soil samples were collected from the monitoring well boring at intervals between 20 and 50 feet bgs. The analytical results indicated concentrations of TPH-g (800 mg/kg), toluene(37 mg/kg),xylenes (87 mg/kg), ethylbenzene(17 mg/kg),and methyl tert 002693.1501.OIBR 2-3 EI C.W.No.2