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<br /> ' March 2002'r'
<br /> >AGE--NC.ProjectNo. 95-0114
<br /> Page`3 of 4
<br /> tops of the screened intervals of wells MW-3R, MW-4 and MW=5,;and at the tops of the screened '
<br /> ' intervals of wells MW-6 to MW-10.Therefore;samples collected from monitoring wells MW-4 and .
<br /> h. MW-5-may not be fully representative of ground water,conditions at or near tfie top�of the saturated
<br /> soil"zone"or 'capillary zone, where -the -greatest hydrocarbon'impact to ground wafer-is often .
<br /> encountered:Note that wells MW-8 and MW-9 are located near wells MW-1 and MW-2. ,
<br /> ' 3.2. PETROLEUM HYDROCARBON-IMPACTED GROUND WATER
<br /> During the February 2002'monitoring event, TPH=ss or,TPH-as gasoline (TPH-g) was detected in--
<br /> sample s.
<br /> n_samples,from monitoring wells MW-3; MW6,MW-7,MW=9,MW-10 at boncentrations of 2,600 ,
<br /> micrograms per liter'(µg11); 800 µg/1,':170 gg/l, 16,000 µg11 and 1,500 µg/l,'respectively,-BTEX
<br /> compounds were detected in well MW-3.and MW-9 samples at concentrations as high as' -'16 gg/l
<br /> (6thY lbenzene).
<br /> The highest concentration of a chlorinated hydrocarbon compound was reported, in the sample'
<br /> collected from well MW-6,cis 1,2-dichloroethene(cis-1,2-DCE)at 1,200 µg/1. This Well is located
<br /> on the south-side of Harding Way, at the northeast edge of the site.-Cis 1,2-DCE Was also reported
<br />.'. in samples from wells MW-3,.MW-7 and MW-10 located near or on the site. Vinyl chloride was'
<br /> reported in samples from wells MW-3,MW-6 and MW-10 at concentrations of 17µg/1, 120 gg/l and
<br /> 890 gg/l,respectively.Tetrachloroethene(PCE)and trichloroethene(TCE)were reported in samples
<br /> from wells MW-3,.MW-6, MW-7 and MW-10, at concentrations as high as 900 µg/1 and 700 µg/l,
<br /> respectively.
<br /> Analytical results for chlorinated hydrocarbon compoundsin ground water samples are summarized
<br /> in Tables 2.and 3. The laboratory report (CalTech'Lab,Nos. 82310 to 82319) for October,.QA/QC
<br /> report and chain-of-custody form.are included in Appendix C.
<br /> A map of dissolved TPH-ss and VOCs is depicted in Figure 2.
<br /> ' 4:0. SUMMARY AND CONCLUSION '
<br /> ' ncluded that-:
<br /> Based upon the results of the,mvestigahon, AGE-co _ •
<br /> • Ground water depths within the established monitoring Wells,were approximately,24 feet
<br /> b�s .'Monitorin wells MW-1 throw MW-5 at'or near the,site are "drowned" with well,
<br /> g g � � � - . .
<br /> screen intervals as much'as ,10 feet below present ground water surface. The recently .
<br /> installed wells'were screened across the current water table level.
<br /> • TPH-ss and TPH-ss as gasoline were detected in the monitoring well'samples on the site and
<br /> Advahe'ed GeoEnvironinental,incr
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