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16 October 2013
<br /> AGE Project No. 99-0682
<br /> Page 2 of 5
<br /> Utilizing site wells, MW-1A, MW-2, MW-3, MW-4, MW-5 and MW-6, net
<br /> /. � groundwater flow direction was inferred to be toward the northeast at a calculated
<br /> Ur ,j, hydraulic gra ientof0.005ootperfoot(ft/ft). Figure�3-illustratescontouredshallow
<br /> r groundwater elevations as measured on 23 September 2013.
<br /> 5 ' ./ Total petroleum hydrocarbons quantified as gasoline (TPH-g) were detected in
<br /> samples collected from wells MVV-1A and MW-6 at concentrations of 44,000
<br /> micrograms per liter(pg/1)and 34b5 pg/I, respectively.Total petroleum hydrocarbons
<br /> quantified as diesel (TPH-d) were detected in the sample collected from well
<br /> MW 1A at a concentration of 9,,300 pg/I.
<br /> Benzene, toluene, ethylbenzene and total xylenes (BTEX) were detected in the
<br /> grou dwater samples collected from well MW-1A at concentrations of 140 pg/I,
<br /> 9,100 pg/l, 2,460 tag/I and 10;f00 pg/I, respectively.
<br /> • Lead scavenger 1,2-dichloroethane (1 ,2-DCA) was detected in the samples
<br /> collected from well MW-1A at a concentration of 2.3 fag/I. rh
<br /> • figure 4 depicts the approximate lateral extent of dissolved chemicals of concern
<br /> (COC) within the water table zone on-site.
<br /> Water-Bearing Zone: 60 to 70 feet bsq
<br /> • Depths to groundwater with this water-bearing zone ranged between 26.30 feet
<br /> (MW-9) btoc and 27.15 feet (MW-11) btoc (Table 1). Groundwater elevations
<br /> ranged between 12.36 feet (MV\r-9) below NAVD88 and 12.58 feet (MW-11) below
<br /> NAVD88.
<br /> • Utilizing wells MW-7, MW-8, MW-9, and MW-11, net groundwater flow direction was
<br /> inferred to be towards the north-northeast, under average hydraulic gradients
<br /> ranging from 0.002 ft/ft to 0.003 ft/ft. Figure 5 illustrates contoured groundwater
<br /> elevations within this water-bearing zone as measured on 23 September 2013.
<br /> •_ TPH-g were detected in samples collected from wells MW-7, MW-8, q d MW-11 at
<br /> 3 concentrations ranging between 14,0 0 fag/I (MW-7) and 160,00 tag/l (MW-8).
<br /> TPH-d were detected in samples Olected from wells MW-7, MW-8, and MW-11 at
<br /> concentrations of 9,700 fag/l, 21,000 pg/l and 6,200 fag/l, respectively.
<br /> BTEX compounds were detected in samples collected from wells MW-7, MW-8, and
<br /> MW-11 at maximum concentrations of 22,000 fag/I benzene, 48,000 fag/I toluene,
<br /> 4,500 pg/l ethylbenzene, and 21,900 fag/l total xylenes (MW-8).
<br /> • Lead.scavenger 1,2-DCA was detected in samples collected from wells MW-7,
<br /> MW-8, and MVV-11 at concentrations ranging between 17 pg/I (MW-7)and 150 pg/I
<br /> (MW-11). The fuel oxygenate tertiary-amyl methyl ether (TAME) was detected in
<br /> Advanced GeoEnvironmental,Inc.
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