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a BTEX compounds were detected in well MW-1 during the January 2002 monitoring event at concentrations of 360 pg/1 benzene, 1,600 gg/l ethylbenzene and 4,700 gg/l xylenes, toluene was not detected during the January 2002 monitoring event,but was detected during the preceding September 2001 monitoring event at 160 pg/l • MTBE was detected in the monitoring well sample from well MW-2 at a maximum concentration of 9 3 gg/1 On 09 to 11 April 2003,five soil borings(CPT-1 to CPT5)were advanced on-and off-site utilizing CPT technology, at each boring location, lithologic data was collected from the initial CPT boring, an immediately adjacent twin boring was then advanced at each CPT location to collect grab ground water samples from selected depths The objective of the investigation was to model the geologic and hydrogeologic frameworks and to assess potential dissolved petroleum-migration pathways beneath the site Soil borings for sounding were as follows • CPT1 was established in the vicinity of monitoring well MW-1 and soil borings A and I to a depth of 150 feet below surface grade (bsg), • CPT2 was established in the vicinity of soil borings B and J to a depth of 160 feet bsg, • CPT-3 was established west of boring C to a depth of 160 feet bsg, • CPT-4 was established south of momtonng well MW-1 and soil borings E and G to a depth of 150 feet bsg, and • CPT5 was advanced at the northeast corner of the intersection of California Stieet and Mine . Avenue to total depths of 160 bsg Ground water and soil samples were ;ollected from CPT bonng locations at the following intervals • CPT-1 was sampicd between 96 and 100 fcet bsg,between 120 and 124 feet bsg and between 146 feet and 150 feet bsg, • CPT--2 was sampled between 93 and 97 feet bsg,between 120 and 124 feet and between 146 and 150 feet bsg and between 181 and 185 feet bsg, • CPT-3 was sampled between 56 and 60 feet bsg, between 104 and 107 feet bsg, between 120 and 124 feet bsg and between 143 and 147 feet bsg, • CPT-4 was sampled between 101 and 105 feet bsg, between 120 and 124 feet bsg and between 141 and 145 feet bsg and • CPT-5 was sampled between 56 and 60 feet bsg,between 104 and 108 feet bsg and between 146 and 150 feet bsg Soil samples were collected from boring CPT1 at 55 and 78 feet bsg The computer-generated CPT lithologic logs were integrated with previous subsurface soil descriptions to construct the subsurface geological model The site stratigraphy is composed predominantly of fine-grained soil consisting of silt, clayey silt, silty clay and clay, with the exception of five significant sand lenses or layers The sand intervals are composed of sandy silt, silty sand, sand or gravelly sand of approximately 15-foot thick or less, and are located at depths of approximately 50 feet bsg, between 60 and 75 feet bsg,between 95 and 110 feet bsg,between 120 Advanced GeoEnvironmentat