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1-4110 California ' -�gional Water Quality Cor A Board <br /> Central Valley Region <br /> ion ioKarl E. Longley, ScD,P.E.,Chair <br /> Linda S.Adams Arnold <br /> 11020 Sun Center Drive#200,Rancho Cordova,California 95670-6114 chwarzene <br /> Secreta or gg <br /> Environmental <br /> Phone(916)464-3291 •FAX(916)464-464y IO � �� f1 Governor <br /> Protection htt //www.waterboards.ca. ov/centralvalle "/ ��LL IJ <br /> SEP 1 7 2000 <br /> 16 September 2009 ENVIRONMENT HEALTi <br /> PERMIT/SERV!or,, <br /> Ms. Shelby Lathrop <br /> ConocoPhillips Company <br /> 76 Broadway <br /> Sacramento, CA 95818 <br /> SECOND QUARTER 2009 STATUS SUMMARY REPORT, FORMER TOSCO BULK <br /> TERMINAL #10013, 3505 NAVY DRIVE, STOCKTON, SAN JOAQUIN COUNTY <br /> California Regional Water Quality Control Board, Central Valley Region (Central Valley <br /> Water Board) staff reviewed the 29 July 2009 Second Quarter 2009 Status Summary <br /> Report (Second QMR) and the 25 August 2009 Well Installation and Oxygen Injection <br /> Report (Report). Stantec Consulting Corporation (Stantec) submitted these documents <br /> on behalf of the ConocoPhillips Company (ConocoPhillips) for the former Tosco bulk <br /> fuel terminal at 3505 Navy Drive in Stockton (Site). ConocoPhillips conducts <br /> groundwater monitoring at the Site pursuant to Monitoring and Reporting Program <br /> (MRP) No. R5-2004-0824. NuStar Energy (NuStar) currently owns and operates the <br /> Site. <br /> The Second QMR describes groundwater monitoring activities performed in May 2009. <br /> During the second quarter, depth to groundwater varied from about three to 14 feet <br /> below ground surface (bgs). The hydrostratigraphy underlying the Site consists of three <br /> progressively deeper water bearing zones called the A, B, and C zones. The A zone <br /> occurs at depths of about 10 to 25 feet bgs, the B zone from 30 to 50 feet bgs, and the <br /> C zone from 55 to 75 feet bgs. The groundwater flow directions in the A, B, and C <br /> zones were to the southwest. The gradients ranged from 0.001 feet per foot (ft/ft) in the <br /> C zone to 0.002 ft/ft in the A zone. The gradients are consistent with previous <br /> observations. <br /> Groundwater underlying the Site is polluted with dissolved petroleum hydrocarbons. <br /> Constituents of concern (COCs) include total petroleum hydrocarbons as diesel (TPHd), <br /> tertiary butyl alcohol (TBA), TPH as gasoline (TPHg), methyl tertiary butyl ether <br /> (MTBE), and di-isopropyl ether (DIPE). Benzene, toluene, ethyl benzene, and xylenes <br /> (BTEX) historically have been essentially non-detect (ND) in Site wells. During the <br /> second quarter, TPHg was detected at 78 micrograms per liter (Ng/L) in downgradient <br /> well MW-17B. TPHd concentrations ranged from 51 to 280 pg/L, and TBA <br /> concentrations ranged from 20 pg/L to 200 pg/L. The highest concentration of MTBE <br /> was 17 pg/L. The highest concentrations of CDCs were generally detected in source <br /> area well MW-2. These concentrations are consistent with historical values. <br /> California Environmental Protection Agency <br /> cps Recycled Paper <br />