ARCHIVED REPORTS XR0002677 - Laserfiche WebLink

Home Browse Search

41 -i. 1 i' yt. ti', •M1 , cl 7 � I •'ii j i1 t 1. 12"A11 ll.]t'2002 r WAGE-NC'Project No: 95-0114 - ;••' < Page 3 of 4' 3.2. -LABORATORY-ANALYTICAL RESULTS'OF'.GROUND.WATER SAMPLES, , During'the Ririe 2002 monitoring.event, TPH-ss was detected in ground water, samples from monitoring wells •MW-2, MW73; MW-6, MW-9; MW-f0''at 'concentrations 'ranging',beiWeen ,. 570 micrograms,per liter (µg/l) in MW-2 to 3,300.[tg/l in MW-9.' ' The BTEX compound eth lbenzenewas detected in'well MW-9 with at-a concentration of;17+g/l. ; The highest concentration of a chlorinated hydrocarbon'compound, cis 1;2-dichloroethene(cis-1,27 re orted in the sample from off--site well MW-10 located northeast of'the WE),at 1,000 �.g/l, was p p , site on the north side of Harding.Way- cis 1',2-DCE'was.also.reported in,the'sample from on-site well 1:. MW-6..In addition, Vinyl chloride was reported in samples from wells MW-3; MW-6 and MW-10. u at concentrations of 50 �Lg/l, 200 µg/l 'and 210 �Lg/l, respectively-, tetrachloroethene (PCE) and trichloroethene(TCE) were reported in samples from wells MW-6, MW-7.and MW-10 at.maximum concentrations of 540 µg/l and 510 �ig/l,respectively'(MW-6); 1;2-dichlorobenzene was detected in samples MW-2 and MW-9 at a maxinrlum concentration of 31 µg/l(MW-9); and trans 1,2-DCE was ; detected in samples MW-6 and MW-10'at a maximum concentration of 18 µg/1 (MW-6). A reap of dissolved TPH-ss and.VOCs is-depicted in Figure 2_Analytical,results for.chlorinated hydrocarbon compounds in ground water samples,are summarized in Table 2. The laboratory report ' (CalTech Lab Nos.0206-060-10 to 0206-060-10)for June;QA/QC report and chain-of.'custody force are included in Appendix B. SUMMARY AND CONCLUSION y 'Based upon the results of the investigation, AGE,concluded that: ; Groundwater depths within.the'established monitoring wells were'between 22.73 and 2426 feet below the tops of the well casings 24 feet bsg;ground watcc:flow direction was northeast at ,a gradient of approximately 0'0018; feet/feet-. Historically; the ground water flow' .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'ground_water 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 tablelevel.Note that wells MW-8 and MW-9 are located near wells MW-1 and-MW-2. • TPH=ss was detected in•the on-site monitoring well samples as well as off site well.MW-10.- 1 ,,, dvanced GeoEnvironmental,Inc.