Laserfiche WebLink
California p-gional Water Quality Control Board < `° <br /> lu <br /> Central Valley Region ` ," <br /> Karl E. Longley, SCD, P.E., Chair <br /> Linda S.Adams Arnold <br /> Secretan�for Sacramento Main Office Schwarzenegger <br /> Emironmental <br /> 11020 Sun Center Drive#200.Rancho Cordova.California 95670-6114 (JOVer170r <br /> Protection Phone(916)464-3291 •FAX(916)464-4645 <br /> http//www.waterboards.ca.eov/centralvalle% (�Ece <br /> �I VIED <br /> Auc i 4 zooT <br /> 13 August 2007 ENVIRONMENT <br /> PERMIT43ERVHCESTH <br /> Mr. Joe Aldridge, Remediation Manager <br /> NuStar Energy L.P <br /> 2330 North Loop 1604 West <br /> San Antonio, TX 78278 <br /> ST SERVICES STOCKTON TERMINAL, 2941 NAVY DRIVE, STOCKTON, SAN JOAQUIN <br /> COUNTY <br /> Regional Water Quality Control Board - Central Valley Region (Regional Water Board) staff <br /> reviewed the: <br /> • 30 April 2007 Groundwater Monitoring Report, First Quarter 2007 (First QMR), <br /> • 5 July 2007 Addendum to Cleanup Plan (Addendum), <br /> • 25 July 2007 Groundwater Monitoring Report, Second Quarter 2007 (Second QMR), <br /> Ash Creek Associates, Inc. (Ash Creek) prepared the documents on behalf of ST Services, <br /> L.L.C. (a subsidiary of NuStar Energy L.P. [NuStar]) for the ST Services Stockton Terminal <br /> located at 2941 Navy Drive in Stockton (Site). Groundwater monitoring at the Site is <br /> conducted pursuant to Monitoring and Reporting Program (MRP) No. R5-2004-0822. The First <br /> and Second QMRs describe groundwater monitoring activities conducted during January and <br /> April 2007, respectively. <br /> The principal contaminants of concern (COCs) include total petroleum hydrocarbons as <br /> gasoline (TPHg), TPH as diesel (TPHd), benzene, toluene, ethylbenzene, and xylenes <br /> (BTEX), tertiary alcohol methyl ether (TAME), methyl tertiary butyl ether (MTBE), tertiary butyl <br /> alcohol (TBA), and di-isopropyl ether (DIPE). ST Services has conducted monitoring at the <br /> Site since 1992, and in 2002, documented gasoline releases from aboveground storage tanks <br /> (ALTs) G 3301 and G 3302. During the same year, a 1,000-gallon diesel release occurred <br /> from diesel AGT D 1503. The plume is commingled with releases from an adjacent facility. <br /> Depth to groundwater ranged from about one to 11 feet below ground surface (bgs) over the <br /> first and second quarters. Ash Creek calculated that horizontal gradients ranged from 0.001 to <br /> 0.004 feet per foot in an east-southeasterly direction in the four water bearing units. Downward <br /> vertical gradients were dominant between the water bearing zones during the three quarters <br /> and ranged from - 0.172 to - 0.001 feet per foot. Historically, downward vertical gradients have <br /> persisted between the water bearing units. <br /> California Environmental Protection Agencp <br /> �p� Rccrcled Paper <br />