ARCHIVED REPORTS_XR0007259 - Laserfiche WebLink

Home Browse Search

Mr Mike Infurna Page 3 . detected in each of the other wells at concentrations ranging from 2 0 ppb in MW5 to 1,200 ppb in MW1 MTBE was reported in the samples collected from wells MW4, MW6 and MW1D at low concentrations ranging from 0 7 ppb in MW6 to 4 3 ppb in MW4 This is the first time that MTBE has been detected in MW4 since monitoring began TBA was only detected in MW6, at a concentration of 20 ppb No other oxygenates or additives were detected Analytical results for oxygenates and additives are summarized in Table 3 Attachment B contains laboratory reports and chain of custody documentation SUMMARY All site monitoring wells were sampled except well UH7, which was not accessible The well box has been paved over with asphalt Concentrations of petroleum hydrocarbons in the monitoring wells were similar to those recorded in the past However, concentrations of TPHg and BTEX in well MW 1 D have shown a dramatic decrease from previous monitoring events TPHg, ethylbenzene and xylenes have been non-detect in MW 1 D for two consecutive sampling events Benzene and toluene were detected at levels ,lust above their respective method detection limits 1,2-DCA was detected in all A and B Zone wells except for wells MW3 and MW7 1,2- DCA was detected in the deep well MWID at a concentration of 3 0 ppb The next groundwater sampling event is scheduled for March, 2005 If you have any questions or comments please contact Ground Zero at your convenience • Respectfully, Ground Zero Analysis, c J&,L— ct) Joseph L Vasquez, � Staff Geologist �N GREGORY P. „L STAHL Gregory P Stahl, RG 5023 No. 5023 CA Certified Hydrogeologist No 264 Attachments cc Mr and Mrs John Ferraiolo Mr Jeff Greenberg, Esq Mr lames L L Barton, CA Regional Water Quality Control Board Ms Marla Nahorn, Environmental Closures Mr Steve Woodhull, Blaes Environmental G 1GROUNDZEIHARRYSIRcports\QMR1200414QM2004a doc