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r. �}. f...w.:a I, l.. q•'" }i IA III{ ,The BTEX=compound ethylbenzene,was'detected in well MW-9'with at'a concentration of 9.3 g, a , y,, `' p 6{ 2 a The:followin chlorinated h drocarbon com ounds we ..e a ected: cis 1 2=dichloaoethene cis=1; DCE)•was'detected in samples,MW-6.and MW-10 at concentrations of•.770 µg01 and 1,200,µg/l, -respectively; 1,2=DCA was detected in sample MW-9 ai'aconcentration of 2$ µg11;tetrachloroethene ,,i (PCE)was.reported iri samples MW-4,MW-6,MW-7 and'MW-10 at a maximum concentration of' 570. µg/1 (MW-10); trichloroethene (TCE) was reported'in samples-,MW-6. and MW-10 at a maximum'concentration of 500µg/l(MW=10);vinyl chloride was reported in samples MW-3,MW=' 6 and MW-10 at amaximuin concentration of 170µg11(MW=40);'and 1,1;1;2-tetrachloroethane and 1�:4-dichlorobenzene were detected-,in sample MW- -9 at'14"µg11 and.4'.0:µg11, respectively: . . ,,Additional VOCs detected in the samples analyzed included'-napthalene"in samples'MW-3,MW=9' and MW. 40 at a maximum concentration of 140"4g/1 (MW-9); ,isopropylbenzene and, n-.' ', propylbenzene in samples MW-3 and MW-9'at maximum concentrations of 80µg/l(MW-3)and 150 pg/l (MW-3 and MW-9), respectively;• and 1,2,4-trimethylbenzene in sample MW-9 at -a concentration-of 6.0 µg/1. ' A map of dissolved TPH-ss and VOCs is depicted in'Figure 2. Analytical results--for"chlorinateds hydrocarbon compounds in ground:water samples are summarized in Tables 2 and 3.The laboratory ` report,(CalTech Lab Nos. 0209-111-1 to 0209-111 8) for'September, QA/QC report and.chain-of ' custody fomri are,incl"uded in Apperidix-B. ' ' • 4,0. SUMMARY AND CONCLUSION ' Based upon the results of the investigation, AGE concluded that: • Ground water depths within-the established monitoring wells were,between 24.97 and 26.57 feet.below the tops of the well casings; ground water flow-direction was northeast at •' a gradient of approximately 0.0015 feet/feet.Historically,the ground watefflow dominantly . has been between north-northwest and`northeast. Monitoring wells MW-1 through MW-5 at or near the site are"drowned"with well screen. intervals as much as 10 feet"below,present groundwater surface.-Samples'collected from 'these wells may not be fully representative of ground water conditions at or near the top of the saturated soil zone or capillary'zone, where the greatest hydrocarbon impact to ground ; .water is often encountered.'The more recently installed wells were screened across the current water table level.Note that wells MW-8 andMW-9 are located near wells MW-1 and ' ' MW-2. • TPH-ss was detected in the on-site monitoring wells MW-3, MW-6, MW=7 and MW-9 as ' well as off-site well MW-10.' The BTEXcompound"'ethylbenzene was detected in on-site well MW-9 at'a concentration. h of 9.3 lig/l. ~Detected concentrations of PCE in`samples,MW-4,MW-6,MW-7 and MW-10`and TCE in samples MW-6 and MW-101exceeded the DHS' Maximum Contaminant Levels(MCLS) in