|
30 January 2014
<br /> AGE Project No . 99-0682
<br /> Page 6 of 28
<br /> / as vapor extraction wells with slotted screen installed from approximately 10 to 20
<br /> feet bsg ; pilot boring MW-7 was completed as a groundwater monitoring well with
<br /> slotted screen installed from approximately 60 to 70 feet bsg ; and pilot boring MW-8
<br /> was completed as a groundwater monitoring well with slotted screen installed from
<br /> approximately 59 to 69 feet bsg . A total of fifteen soil samples collected from pilot
<br /> soil borings VW-1 through VW-4 and MW-7. TPH-g was detected in three soil
<br /> samples collected from VW- 1 ( 20 feet, 25 feet and 30 feet) , three soil samples
<br /> collected from VW-3 ( 20 feet, 25 feet and 30 feet), and two soil samples from MW-
<br /> 7 (60 feet and 70 feet); concentrations ranged from 1 . 1 mg/kg (MW7-70) to 6, 800
<br /> mg/kg (VW3-20 ) . BTEX constituents were detected in three soil samples collected
<br /> from VW- 1 ( 20 feet, 25 feet and 30 feet) , three soil samples collected from VW-3
<br /> ( 20 feet, 25 feet and 30 feet), and one soil sample from MW-7 (70 feet); maximum
<br /> concentrations were 0.024 mg/kg benzene (MW7-70), 270 mg/kg toluene (VW1 -
<br /> 30), 220 mg/kg ethylbenzene (VW1 -20 ) , and 950 mg/kg xylenes (VW3-20) .
<br /> February 2008 - Cone penetration testing and grab groundwater sampling was
<br /> conducted on-site and off-site (521 East Oak Street) utilizing a CPT drill rig . Ten
<br /> grab groundwater samples were collected from borings CPT-6 , CPT-7 , CPT-8 , B-5
<br /> and B-6 from two water bearing zones (67 to 75 feet bsg and 124 to 130 feet bsg).
<br /> TPH-g was detected in samples CPT7-75, CPT8-70 , and 136-75 at concentrations
<br /> of 1 , 800 micrograms per liter (tag/1 ), 90, 000 pg/I and 3, 300 pg/l , respectively. TPH-d
<br /> was detected in samples CPT7-75 , CPT8-70, and 136-75 at concentrations of 4, 800
<br /> pg/13 8 ,400 pg/I and 5, 600 pg/l , respectively. Two or more BTEX compounds were
<br /> detected in samples CPT7-75 , CPT8-70 , and 136-75 at maximum concentrations of
<br /> 31300 pg/l benzene , 4 ,200 pg/I toluene , 3 ,000 pg/I ethylbenzene , and 13 , 100 pg/I
<br /> total xylenes in sample CPT8-70 . TAME and 1 ,2-DCA were detected in sample
<br /> CPT8-70 at concentrations of 290 pg/I and 82 pg/I , respectively.
<br /> March 2008 - Two groundwater monitoring wells , MW-9 and MW- 11 , were installed
<br /> on-site and one groundwater monitoring well , MW-10 , was installed off-site at 521
<br /> East Oak Street. A total of eleven samples were submitted for laboratory analysis
<br /> during the investigation .
<br /> TPH-g was detected in soil samples collected from MWA0 at depths of 60 feet and
<br /> 70 feet bsg at concentrations of 13 milligrams per kilogram (mg/kg ) and 1 .2 mg/kg ,
<br /> respectively. BTEX compounds were detected at a depth of 70 feet bsg at
<br /> concentrations of 0 .010 mg/kg benzene, 0 . 028 mg/kg toluene , 0 .010 mg/kg
<br /> ethylbenzene and 0. 060 mg/kg total xylenes . TPH-g was detected in soil samples
<br /> collected from MW-11 at depths of 60 feet, 65 feet and 70 feet bsg at
<br /> concentrations of 320 mg/kg , 340 mg/kg and 44 mg/kg , respectively. TPH-d was
<br /> 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. BTEX
<br /> compounds were detected at depths of 60 feet, 65 feet and 70 feet bsg at maximum
<br /> Advanced GeoEnvironmental, Inc.
<br />
|