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<br /> w Y% r ,:: :12:February2002 ;,f •;; ' I . . � �' ':
<br /> AGE-NC Ploject'No 95 0114
<br /> Page 2'of 6 t
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<br /> ,ground,water A total,o f 20 ground water momtoring'events have occurred at the site -The follow;ng• f
<br /> is,a summaiy of milestone events•at'the site
<br /> Ground water monitoring wells MW-l,MW 'and MW-3 Frere installed at the site site n'
<br /> J
<br /> 1993: During' well-development-,a'surge block-ivas-lodged within well MW-3; MW3 had-,
<br /> consistently failed 'to produce sufficient-ground. water to meet the pre sampling purge
<br /> requirements. Subseouently MW=3 was over drilled 6n.07•December ,1995 and grouied'to,
<br /> surface grade with Portland-cement.,
<br /> Three additional ground water rAonitoring-wells j(MW�3R,'.MW.-4 andMW-5)were installed
<br /> f `
<br /> :
<br /> -in ,December 1995. Petroleum hydrocarbons were not detected in soil'sarnples, collected'
<br /> during the installation of wells MW,-4 or MW-5, however, hydrocarbon-impacted ground
<br /> water was detected in samples collected'from' MW-3R. Results of
<br /> in procedures, '
<br /> -were included'in'the-Quarterly Report "'December 1995, prepared by AGE: '
<br /> In January 2000, two soil.botin s'were advanced at-the site and.two r ound water wells
<br /> g �•
<br /> (MW-band MW-7) were'' talled. The MOA iintense TPH-ss imgacted.graund water was ': M"'.
<br /> detected within the formenUST area.
<br /> In Aptil 2001, extraction well EW-1 and:monitoring wells MW-S;.MW-9;and MW-10.Were'-'-
<br /> installed.
<br /> ere'-installed.
<br /> • Soil and, ground•water on the site have been impacted with petroleum hydrocarbons as. 4=P.
<br /> stoddard solvents and BTEX. Additionally,tetrachloroethene(PCE),cis 1",2-dichloroethene,:. '
<br /> (1,2 DCA)and vinyl chloride were detected in the water sarziples collected from wells MW-4,
<br /> MW-5; MW-6 and MW-7.
<br /> •. TP.H-ss has been detected in=on-site,ground-water monitoring well samples,but has not been',
<br /> detected in'downgradient monitoring well.samples'at the edges and outside of the site'(MW6;.
<br /> F - •MW-7' and'MW-10). BTEX eornpounds were not detected'in<ah1. y`of the'ground water. 1
<br /> samples.
<br /> • PCE and TCE have been detected ingroundwater samples collected from we11s,MW-6,MW-
<br /> -.7 and MW-10, at concentrations-which exceeded the-Ma.xiuium'Contaminant Level(MCL)
<br /> -of-5 µg/1 established by the State.of California - Department of Health Services.''`Detected
<br /> concentrations of cis 1,2-dichloroethene and vinyl chloride also exceeded the-State MCL of
<br /> 6 µg/l:
<br /> �y The lateral extent of the dissolved halogenated-hydrocarbon plurrie has not been defined east'
<br /> or north of wells MW-6 and MW-10. ;
<br /> •.„ -In August 2001 a ground water extraction test was conducted at,the site.Ground water draw- '
<br /> down of'at least 18.feet.was observed in extraction well EW-1.following,720 minutes of
<br /> continuous,purrmping'(5. GPM); ground,water draw-down was observed focally at 0.37 feet,' x
<br /> to 0.1 feet.
<br /> x r - ,Advanced GeoEnvironmenta Inc.
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