Laserfiche WebLink
S E C ® R <br /> Mr Harlin Knoll <br /> January 23, 2006 <br /> Page 3 <br /> CONCLUSIONS <br /> The concentrations of TPHg, TPHd, BTEX, and MtBE have shown consistently decreasing <br /> trends in reported concentrations since 1998 In fact, the detected concentrations of TPHg <br /> and TPHd in downgradient wells MW-1, MW-5, MW-6A, and MW-6B have approached non- <br /> detect over the past several sampling events, and MtBE concentrations have been reported <br /> at less than its primary MCL for over 2 years In addition, no constituents for which <br /> analyses have been performed have ever been detected in well MW-613, indicating that the <br /> vertical extent of groundwater impact has been defined, and the petroleum-hydrocarbon <br /> impact to groundwater is limited to shallow groundwater at the site in the vicinity of the <br /> former tank and product dispenser islands Furthermore, it appears that the concentrations <br /> of detected petroleum hydrocarbons in these areas have shown a consistent decrease over <br /> the past 6 to 7 years This implies that any residual impact to groundwater in the vicinity of <br /> former Chevron service station 9-8632 is localized to shallow groundwater in the vicinity of <br /> the former tank and product line area and is consistently decreasing with time <br /> RECOMMENDATIONS <br /> . Chevron and SECOR would appreciate an opportunity to meet with San Joaquin county <br /> Environmental Health Department (EHD) representatives in early 2006 to discuss future <br /> activities for this site In particular, we would be interested in discussing additional work or <br /> characterization necessary to bring this site to closure <br /> If you have any questions or concerns regarding the contents of this report, please feel free <br /> to contact George Forsythe at (559) 271-2650, ext 235 <br /> Sincerely, <br /> SECOR International Incorporated <br /> T FOAL,`-OPS <br /> George Forsythe, P G <br /> Senior Geologist " No s.O f *^ <br /> OF 0A1-��OQ� <br /> N 1FdeslProjectslChevron4RetatA#9-8632(Tracy)1Penodfc MonrtonngQ00514QMR05WQ2005 QMR 98632 doc <br />