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1 ' Site Background Information FORMER F1SC0 WAREHOUSE (Howard Lenz Property) ' 1648 Shaw Road, Stockton, California PREVIOUS SUBSURFACE INVESTIGATION ' On 18 September 1997,five soil robe borings -1 throw B-5 were advanced at the site to assess P P g CB � ) the lateral and vertical extent of petroleum-impacted soil. TPH-g was detected in samples from B 1, ' 133 and B5 at concentrations as high as 14,000 mg/kg.Benzene was detected in onlyone sample(B 1- 40), which contained a concentration of 0.042 mg/kg. Toluene, ethylbenzene and xylenes were detected in samples from 131, B3 and B5 at concentrations as high as 1,600 mg/kg (xylenes in B5- 25). TPH-d was detected in samples from B-1, B-3 and B-5 at concentrations as high as 12,000 mg/kg(133-10,B3-15).None of the samples analyzed from borings B-2 or B-4 contained detectable ' concentrations of TPH-g, TPH-d, BTEX or MTBE. From 22 to 24 February 2000, four soil borings (MW-1 through MW-3 and B-6) were advanced at ' the site. TPH-g was detected in 9 of the 16 soil samples analyzed at concentrations as high as 6,700 mg/kg; TPH-d was detected in 7 of the 16 soil samples analyzed at concentrations as high as 5,800 mg/kg. Benzene was detected in 4 of the 16 samples at concentrations as high as 0.027 mg/kg. Toluene, ethylbenzene and xylenes were detected in 11 of 16 samples at concentrations as high as 370 mg/kg. MTBE was not detected in any samples analyzed. Petroleum hydrocarbons were not detected in 5 of the 16 soil samples analyzed. In February 2001,four pilot soil borings were advanced at the site.Pilot borings MW4 through MW7 were completed as ground water monitoring wells using two-inch diameter PVC casing with 0.020- inch slotted screen installed from approximately 60 feet to 40 feet bsg and with blank casing extended to the surface. A total of 16 soil samples were analyzed for TPH-g, TPH-d, BTEX,EDB, 1,2-DCA and the suite of five fuel additives. None of the analytes were detected at or above laboratory reporting limits in the soil sample analysis. On 10 and 11 January 2002, three soil boring (CPT-1, CPT-2 and CPT-3) were advanced on-site utilizing CPT technology to model the geological and hydro-geological framework and to assess potential dissolved petroleum-migration pathways beneath the site. Soil borings CPT-1,CPT-2 and CPT-3 were advanced vertically to total depths of 96 feet bsg, 134 feet bsg and 125 feet bsg, respectively, utilizing a 25-tan truck-mounted CPT drill rig equipped with 1.50-inch diameter hollow-stem rods. A total of five grab ground water samples were collected from CPT-1,CPT-2 and CPT-3 and submitted for laboratory analysis for TPH-g, TPH-d, BTEX, EDB, 1,2-DCA and the suite ' of five fuel additives. Groundwater samples were collected from: CPT-1 at between 92 feet and 96 feet bsg(CPT 1-92-96); CPT-2 at between 76 feet and 80 feet bsg(CPT2-76-80)and between 92 feet to 96 feet bsg(CPT2-92-96); and CPT-3 at between 74 feet and 78 feet bsg (CPT3-74-78) and between 92 feet and 96 feet bsg (CPT3-92-96). Advanced GeoEnvironmental,Inc