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41
<br /> Gil
<br /> ,` 1Q:Decelnber,200i _
<br /> ' r 'AGE-NC Pxoject No.:95 01"r4", ` r' _ ;.•f
<br /> summaiized in Tab1e,l..The contoured relative.ground water'eievati`on fot-,the October,2001 ground F
<br /> Y water monitoring event is"depicted in'Figure 3.-.-''
<br /> Wells,MW-1 and MW-2 are screenedbetween,34 and'54�feet bsg, wells MW-3R,MW-4 and MW;5,'
<br /> are screened betwe&ri 30 and 50 feet bsg;wells MW-6 through_MW-10 are screened between 25 and
<br /> 45'6r' 50;feet bsg. Ground vvr-is more than-10feet above the tops-of the screened intervals of wells
<br /> 1VIW'1-and MW-2,'6'feet above the tops of the screened interval"§of wellslVIW-3RMW-4 and MW-
<br /> •5, and at tM:tops ofthe'screened intervals,ofwells MW-6 to MW-10. Therefore;:'samples,collected',"
<br /> ' from liionitoririg,wel'ls MW-1,. through MW-5 may not be .fizlly representative of'ground 'water -
<br /> '' conditions at or near.the top .of the saturatedsoil;,zone'or capillary zone, 'where Ah6 greatest ;
<br /> 'hydrocarbon impact to groundwater.,is'ofteri.'eilcouriteied. Note that wells'MW-8,and MW-9-are,.
<br /> located near.wells MW-1 and MW-2.
<br /> PETROLEUM HYDROCARBONXVPACTED'GROUND WATER.,'-
<br /> 'During the October 2001 monitoring.event,TPH-ss was detected•in samples from monitoring wells .
<br /> MW-2;1VIW-3; MW6, MW8 and-MW-9' at concentrations of 93 micrograms per liter (;c g11), 1;400
<br /> µg/l, 150"Ug/l, 54 null and 3,100-,ug/j, respectively.•BTEX compounds were detectea'in3well:MW=3.
<br /> and.MW=9 at concentrations as-Ihigh as'17',ugI (ethyl-benzene).. Analytical results of ground water
<br /> .. 'samples are-summarized in Table 2.'The 'laboratory repbft. (McCampbelli A.halytical Laboratory
<br /> ' Reference No. 8231 Oto.82319); quality assurance and quality control'(QA/QC),report and chain-of J '
<br /> ,Custody form.for the Oetober,2001'ground water m6nitoring,event are included in-Appendix C.
<br /> 'F _
<br /> A map of dissolved TPH- ss'and VOCs is depicted in Figure 4.'
<br /> 3:3. CHLORINATED'HYDROCARBON-IMPACTED GRQUND WATER
<br /> Dunng tlic°October;2001 sampling event;the high6st concentration of.chlorinated colxipouriti were�-'
<br /> reported within sarni les collected from_well MW:-IO, cis'1,2-dichloroetherie (cis-1;2-DCE)nat;810.,
<br /> Il in This well is locatedon'the north side'of Harding Y•Wa Cls 1,2-DCE was also reported in
<br /> • s µg_ .._ p .
<br /> ' samples °from wells'MW-3; MW=6 and MW=7,located'rlear or.on the site.:Vinyl chloride was
<br /> reported in samples froin.wells MW-3,'MW-6 and MW=10 at concentrations-of 250.Ag/1,110 uglF
<br /> 'and 110.'µg/l,.respectiw61Y.,
<br /> Tetrachloroethene {PCE) and trichlomethene (TCE);were reported in samples,frM wells MW--6,,
<br /> MW-73.and,MW-10, 'at concenirations'as'High as' 390 ccg/l° and 270 g/1, 'respectively. 1;2 =r
<br /> dichlorobenzene:was' detected in the samples'froth wells MW 2 an1. d'1VIW-9:at;concentrations of
<br /> ' 1.2 Ltg/1.and 21 �cgll, respectively.
<br /> ,1Advanced GeoEnvironmeotaE,lnc• ;
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