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M w Site Background Information: Stallworth Auto Sales Page 5 of 10 I'I high as 9,300 µg/1 benzene and 49,000 µg/l toluene in HU8, and 5,500 µg/l ethylbenzene and 259500 µg/1 total xylenes in HU9/10 . BTEX constituents were not detected in the ground water samples collected from CPT-2 . • 1 ,2-DCA was detected in the water samples collected only from CPT-3 at concentrations of 37 µg/l in HU8 and 23 µg/1 in HU9/10 . On 18, 19 and 20 January 2006, one soil boring was advanced and two deep ground water monitoring wells (MW- 1C and MW- 1D) were installed at the site. A CME-95 truck-mounted drill rig was utilized to advance soil borings B4, MW4 C and MW4D to total depths of 150 feet below surfacegrade (bsg), 135 feetbsg and 150 feet bs , res respectively, using 8-inch diameter hollow-stem L. augers . Soil samples were not collected in borings MW- 1C and MW- 1D . No soil samples were collected in boring B-4 until 50 feet bsg. In addition, ground water samples were collected from h , wells MW- 1C and MW- 11). Pilot borings MW4C and MW- 1D were completed as ground water J monitoring wells of the same designations using 2-inch diameter polyvinylchloride (PVC) casing with 0 .010-inch slotted screen installed from 125 feet to 135 feet bsg and 140 to 150 feet bsg, respectively. i • TPH-g was detected in the soil samples collected from B4 at 60 feet, 70 feet, 90 feet, 100 feet, 130 feet and 149 feet bsg. Concentrations ranged from 2 .0 mg/kg (B4400) to 2,500 mg/kg (B4-70) . • BTEX constituents were detected in the boring B4 samples from 60 feet, 80 feet, 90 feet, 130 feet and 149 feet. Maximum concentrations were detected in sample B4-70 at 4.7 mg/kg benzene, 32 mg/kg toluene, 7. 9 mg/kg ethylbenzene and 45 mg/kg xylenes. • TPH-g was detected in the ground water samples collected from wells MW4Cand MW- 1D at concentrations of 3,800 micrograms per liter (µg/1) and 6,400 µg/l, respectively. • BTEX constituents were detected in the samples from wells MW- 1C and MW41) with j maximum concentrations in well MW- 1D at 170 µg/1 benzene, 870 µg/1 toluene, 180 µg/l ;{ ethylbenzene, and 760 µg/1 xylenes. • The fuel oxygenates MTBE and DIPE were detected in well MW- 1D at concentrations of 9 . 8 µg/l and 3 . 6 µg/1, respectively. DIPE was detected in well MW- 1 C at a concentration of 4.4 µg/1. The lead scavenger 1 ,2-DCA was detected in both wells at concentrations of 3 . 0 µgll and 5 .4 µg/1, respectively. On 26 and 27 January 2006, soil boring CPT-5 was advanced off-site, at 540 North California Street utilizing CPT technology to model the geologic and hydrogeologic framework and to assess potential dissolved petroleum migration from the site. Lithologic data was collected from an initial CPT soil boring; adjacent borings were then advanced to collect grab ground water samples from selected depths . Soil boring CPT-5 was advanced to atotal depth of 200 feet bsg. Groundwater samples were Advanced GeoEnvironmentaI, Inc. .�