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Site Background Information: Stallworth Auto Sales
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<br /> at a maximum concentration of 90,000 µg/1 in vapor during the lower vadose SVE pilot test.
<br /> On 05, 06 and 07 February 2008, cone penetration testing and grab ground water sampling was
<br /> conducted on-site and off-site (521 East Oak Street) utilizing a 25-ton truck-mounted CPT drill rig.
<br /> Ten grab ground water samples were collected from borings CPT-6, CPT-7, CPT-8, B-5 and B-6
<br /> from two water bearing zones (67 to 75 feet bsg and 124 to 130 feet bsg). TPH-g was detected in
<br /> samples CPT7-75, CPT8-70, and 136-75 at concentrations of 1 , 800 micrograms per liter (µg/1),
<br /> 905000 µg/1 and 3,300 gg/l, respectively, TPH-d was detected in samples CPT7-75, CPT8-70, and
<br /> 136-75 at concentrations of 4, 800 µg/1, 8,400 gg/1 and 5,600 gg/l, respectively. Two or more BTEX
<br /> compounds were detected in samples CPT7-75, CPT8-70, and B6-75 at maximum concentrations
<br /> of 3,300 gg/l benzene, 4,200 µg/l toluene, 3 ,000 gg/l ethylbenzene, and 13, 100 µg/1 total xylenes
<br /> in sample CPT8-70. TAME and 1 ,2-DCA were detected in sample CPT8-70 at concentrations of290
<br /> µg/1 and 82 gg/l, respectively. Chemicals of concern (COC) were not detected in any grab ground
<br /> water samples collected within the 124 to 130 feet bsg water bearing zone.
<br /> Based upon the above analytical results of grab ground water samples collected during the CPT
<br /> investigation, on 13 and 14 March 2008, two ground water monitoring wells, MW-9 and MW- 11 ,
<br /> were installed on-site and one groundwater monitoring well, MW- 10, was installed off-site at 521
<br /> East Oak Street. COC were not detected at or below detection limits in the soil samples analyzed
<br /> from boring MW9.
<br /> The following COC were detected in the soil samples collected from boring MW 10:
<br /> • TPH-g was detected in soil samples collected from MW 10 at depths of 60 feet and 70 feet
<br /> bsg at concentrations of 13 milligrams per kilogram (mg/kg) and 1 .2 mg/kg, respectively.
<br /> • BTEX compounds were detected at a depth of 70 feet bsg at concentrations of 0.010 mg/kg
<br /> benzene, 0.028 mg/kg toluene, 0. 010 mg/kg ethylbenzene and 0.060 mg/kg total xylenes.
<br /> The following COC were detected in the soil samples collected from boring MW l 1 :
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<br /> • TPH-g was detected in soil samples collected from MW l l at depths of 60 feet, 65 feet and
<br /> 70 feet bsg at concentrations of 320 mg/kg, 340 mg/kg and 44 mg/kg, respectively.
<br /> • TPH-d was detected in soil samples collected at depths of 50 feet, 60 feet and 65 feet bsg at
<br /> concentrations of 150 mg/kg, 140 mg/kg and 130 mg/kg, respectively.
<br /> • BTEX compounds were detected at depths of 60 feet, 65 feet and 70 feet bsg at maximum
<br /> concentrations of 0 . 17 mg/kg benzene (60 feet bsg), 4. 0 mg/kg toluene (60 feet bsg), 1 .9
<br /> mg/kg ethylbenzene (60 and 65 feet bsg), and 11 .7 mg/kg total xylenes (60 feet bsg) .
<br /> • TAME was detected at depths of 60 feet, 65 feet and 70 feet bsg at concentrations of 0 . 11
<br /> mg/kg, 0. 15 mg/kg and 0.060 mg/kg, respectively.
<br /> Advanced GeoEnvironmental, Inc.
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