ARCHIVED REPORTS_XR0008090 - Laserfiche WebLink

Home Browse Search

I ' 25 February 2005 • AGE-NC Project No 96-0229 ' Page 4 of 6 ' (Figure 4),off-site towards the north and northeast(wells MW-6 through MW-12),net ground water flow was oriented more towards the north-northeast at an average hydraulic gradient of 0 005 ft/ft ' 3 12 Second Water Zone ' Ground water elevation data collected in the Second Water Zone (70 to 95 feet bsg) at the site and off-site (wells MW-5 and MW-6 through MW-12) inferred a net ground water flow direction towards the east at hydraulic gradients between 0 007 ft/ft and 0 008 ft/ft (Figure 5) 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES ' A total of forty-one ground water samples were submitted to Ca Tech Environmental Laboratories (CTEL), a DHS-certified laboratory in Paramount, California iTPH-g was detected in ground water samples collected from wells MW-1 through MW-4, MW-6 • and MW-9 at concentrations as high as 53,000 micrograms per liter (µg/1) in well MW-2 i BTEX compounds were detected In samples MW-1 through MW-4 MW-6 and MW-9 at p P g i concentrations as high as 8,800 µg/l (xylene, MW-2), the highest benzene concentration was detected In sample MW-1 at a concentration of 3,100 µg/l i The fuel additive MTBE was detected by EPA Method 8260 in samples MW-1 through MW-4, MW-6, MW-9, MW-16 (B-C), and MW-19A at concentrations as high as 600 µg/1 (MW-9), in addition, 1,2-DCA was detected in the ground water samples collected from wells MW-1 and MW-2 i at concentrations of 170 µg11 and 12 µg/1,respectively, and DIPE was detected in one ground water sample collected from well MW-1 at a concentration of I 1 µg11 i No other constituents of concern were detected above laboratory reporting limits In the analyzed samples Previous and current analytical results of ground water monitoring well samples are summarized In Table 3 The laboratory reports (CTEL Project Number CT214-0410004), quality assurance/quality control(QA/QC)reports and chain of custody forms are presented in Appendix B GeoTracker confirmation pages of the submitted laboratory electronic deliverable format(LOP)files are included in Appendix C i 4.0. SUMMARY AND CONCLUSIONS The implications from the findings of the September 2004 round water monitoring event are • P g p g iAdvanced CeoEn"ronmental,Inc i