Laserfiche WebLink
07 July 1997 <br /> AGE-NC Project No 95-0121 <br /> Page 3 of 4 <br /> MW-7 The highest concentrations of TPH-g was reported from MW-7 at 55;000 yg/l (micrograms <br />' per liter or parts per billion ppb), while the lowest was reported from MW-6 at 62 ppb <br /> a <br /> TPH-d was'detected in ground water samples collected from wells MW-1 through MW-9 The <br />' highest concentrations of TPH-d was reported from MW-3 at 20,000 ppb, while the lowest was <br /> reported from MW-6 at 180 ppb, however the laboratory reported these TPH-d detections had <br />' chromatograms with non-diesel patterns and characteristics <br /> Benzene was detected in ground water samples collected from wells MW-1 through MW-4, NNW-6 <br />' and MW-7 The highest concentrations of benzene was reported from MW-3 at 8,500 ppb, while the <br /> lowest was reported from MAN'-6 at 0 65 ppb Toluene,-Ethylbenzene and Xylenes were detected in <br /> samples collected from wells MW-1 through MW-4 and MW-7 The highest concentrations were <br />' reported from MW-3 at 3,600 ppb, while the lowest concentrations were reported from MW-7 at,33 <br /> ppb <br />' MTBE was detected in a ground water sample collected from MW-5 at a concentrations of 6 ppb <br /> The analytical results for ground water samples are su nmarized in Table 2 -Analytical Results of <br /> Ground Water Samples The laboratory report (Castle Analytical Laboratory Reference No 112 1) <br /> and chain-of-custody forms are included in Appendix B <br />' 4.0. CONCLUSIONS/SU-IliMARY <br /> Based upon data collected during the May 1997 monitoring, AGE concludes the following <br /> I <br /> Since December 1994 to May 1997, ground water flow direction at the site has remained <br /> constantly toward the northeast Monitoring wells MW-6 and MW-9 continue to be up- <br /> gradient of the former UST area, MBS'-4, MW-5 and NiW-8 continue to be down-gradient <br /> • Laboratory data continues to indicate that the greatest concentrations of dissolved petroleum <br />' hydrocarbons are located near MW-1 through MW-4 ("core area") <br /> • Concentrations of benzene detected in wells MW-N through MW-4 and MW-7 exceeded the <br /> State of California Maximum Contaminant Level (MCL) for drinking water of 1 0 Pg/l <br /> • Concentrations of toluene detected in wells MW-I and MW-3 exceeded the MCL of 150 <br /> Concentrations of MTBE in well MNV-5 were below the State of California Drinking Water <br /> Action Limit (AL) of 35 ppb However, further laboratory review of sample chromatograms <br /> from wells MW-1 through MW-3 indicated that MTBE was present, but not detected due to <br /> increased dilution factors 1 <br /> t <br />