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Site Background Information: Fisco Warehouse ' Page 3 of 6 Hydrostratigraphic Unit 3 (HU3)extends from 96 feet bsg to and possibly beyond 134 feet bsg. Silt ' and clay are the dominant soil type in the interval, though sand is present. The interval is characterized by pore pressure variations from moderate to high pressures. ' Hydrostratigraphic units are depicted in cross sectional views A-A' and B-B'. PREVIOUS SUBSURFACE INVESTIGATION ' On 18 September 1997, five soil probe borings (131 through B5) were advanced at the site to assess the lateral and vertical extents of petroleum-impacted soil.Total petroleum hydrocarbons quantified as gasoline (TPH-g) were detected in samples from Bl, 133, and 135 at concentrations as high as I 14,000 mg/kg.Benzene was detected in only one sample(B 1-40),at a concentration of 0.042 mg/kg. Toluene,ethylbenzene,and xylenes were detected in samples from B 1,B3,and B5 at concentrations as high as 1,600 mg/kg (xylenes in 115-25). TPH-d was detected in samples from B1,133,and B5 at concentrations as high as 12,000 mg/kg (B3-10 and 133-15). None of the samples analyzed from borings B2 or B4 contained detectable concentrations of TPH-g, TPH-d, volatile aromatic compounds benzene, toluene, ethylbenzene, and xylenes (BTEX), or methyl tertiary-butyl ether (MTBE). From 22 to 24 February 2000, four soil borings (MW-1 through MW-3 and B6) were advanced at the site. TPH-g was detected in nine of the 16 soil samples analyzed at concentrations as high as 6,700 mg/kg;TPH-d was detected in seven of the 16 soil samples analyzed at concentrations as high as 5,800 mg/kg. Benzene was detected in four of the 16 samples at concentrations as high as 0.027 mg/kg. Toluene, ethylbenzene, and xylenes were detected in eleven of the 16 samples at concentrations as high as 370 mg/kg. MTBE was not detected in any samples analyzed. Petroleum hydrocarbons were not detected in five of the 16 soil samples analyzed. borings M -4 through In February 2001, four pilot soil borings were advanced at the site. Pilot bo gs W h o g MW-7 were completed as ground water monitoring wells using two-inch diameter PVC casings with M 0.020-inch slotted screens installed from approximately 60 feet to 40 feet bsg and with blank casing extending to the surface. A total of 16 soil samples were analyzed for TPH-g, TPH-d, BTEX, 1,2-dibromoethane(EDB), 1,2-dichloroethane(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 geologic and hydrogeologic framework and to assess potential dissolved petroleum migration pathways beneath the site. Soil borings CPT-1, CPT-2, and CPT-3 Iwere advanced vertically to total depths of 96 feet bsg, 134 feet bsg, and 125 feet bsg, respectively, • utilizing a 25-ton truck-mounted CPT drill rig equipped with 1.50-inch diameter hollow-stem rods. I Advanced GeoEnvironmental,Inc