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Site Background Information - Fernando ' s Place AGE-NC Project No. 00-0769 Page 3 of 5 185 feet bsg. TPH-g was detected rom CPT-08-185 feet bsg only, at a concentration of 27 mg/kg. BTEX compounds were detected from CPT-08- 185 feet bsg only, at concentrations of 0 .47 mg/kg benzene, 12 mg/kg toluene, 1 . 6 mg/kg ethylbenzene and 10.2 mg/kg total xylene; while 1 ,2-DCA were detected in CPT-08-185 feet bsg only at a concentrations 0.026 mg/kg. Grab water samples were collected from CPT-07 at depths of 181 feet bsg (HU4), and 231 feet bsg (HU6). TPH-g was detected from both of the grab water samples at concentrations of 88,000 micrograms per liter (µg/1) in CPT-07- 181 feet bsg and 110,000 lig/1 in CPT-07-231 feet bsg. BTEX compounds were detected from both of the grab water samples at concentrations of 960 µg/1 and 2,900 µg/1 benzene (at 181 feet bsg and 231 feet bsg , respectively); 950 µg/I and 9,600 µg/l toluene (at 181 feet bsg and 231 feet bsg , respectively); 850 pg/I and 1 ,200 µg/1 ethylbenzene (at 181 feet bsg and 231 feet bsg , respectively); and 5 ,500 µg/1 and 5,600 gg/l total xylenes (at 181 feet bsg and 231 feet bsg , respectively). 1 ,2-DCA were detected from both water samples collected from CPT-07 at concentrations of 7 .5 lig/I and 89 µg/l 1 ,2-DCA, (at 181 feet bsg and 231 feet bsg , respectively). HYDROGEOLOGIC UNITS Based on cross sectionsA A ' andB-B ', AGE informally identified five hydrologic flow units, located between first encountered ground water and 199 feet bag, as having significant intervals of apparently porous, coarser-grained soil separated by intervals of finer-grained, less permeable soil. Hydrogeologic Unit 1 (HU-1) was subdivided into three sub-units (HU4 Upper Zone, 11U-1 Middle Zone, and HU-1 Lower Zone) that may not have significant barriers to vertical migration of contaminants. Generally, HU-1 Upper Zone was identified at depths between 25 feet (first encountered ground water) and 51 feet bsg; HU-1 Middle Zone was identified at depths between 48 feet and 75 feet bsg; HU-1 Lower Zone was identified at depths between 60 feet and 90 feet bsg. Hydrogeologic Unit 2 (HU-2) was identified at depths between 112 feet and 125 feet bsg and consists primarily of a continuous layer of sand. Hydrogeologic Unit 3 (HU-3) was identified at depths between 140 feet and 160 feet bsg and consists primarily of a continuous layer of sand. Hydrogeologic Unit 4 (HU-4) was identified at depths between 160 feet and 175 feet bsg and consists of a locally contained layer of sand. Hydrogeologic Unit 5 (HU-5) was identified at depths between 190 feet and 199 feet bsg and consists of a locally contained layer of sand. HYDROCARBON-IMPACTED SOIL Based on the analytical results of soil samples collected during the site assessment scope, cross sections illustrating the inferred vertical and horizontal extent of hydrocarbon-impacted soil were constructed: hydrocarbon-impacted soil appears to be defined vertically, although the lateral extent of impacted soil is less defined at the site. However, ground water impacted at the water table is Advanced GeoEnvironmental, Inc.