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California Regional Water Quality Control Board <br /> Central Valley Region _ <br /> -�i <br /> Katherine Hart,Chair <br /> ('%E l - Arnold <br /> Linda S. Adams 1172-0 Sun Center Drive#200,Rancho Cordova,California 95670-6114 Sec,•era,y for Schwatzenegger <br /> Phone(916)464-3291 •FAX(916)464-4645 Governor <br /> Environmental DEC 17 2010 http://www.waterboards.ca.gov/centralvalley <br /> Protection li <br /> � 1 ENVIRONMENTAL HEALTH 16 December 2010 <br /> Ar. Joe AldrPc�g' ITisERVlcPn <br /> NuStar Energy L.P. <br /> 2330 North Loop 1604 West <br /> San Antonio, TX 78278 <br /> GROUNDWATER MONITORING REPORT THIRD QUARTER 2010 AND D ZONE MONITORING <br /> WELL INSTALLATION REPORT, NUSTAR TERMINALS STOCKTON FACILITY, 2941 NAVY <br /> DRIVE, STOCKTON, SAN JOAQUIN COUNTY <br /> Regional Water Quality Control Board, Central Valley Region (Central Valley Water Board) staff <br /> I-evie'vved the 1 Novem'Dor 2010 Croon-d-Alutcr MCnifnririri Rennrt Third (`darter 2(110 (Third (-)MR) <br /> and the 12 November 2010 Monitoring Well Installation Report (Report), submitted by Ash Creek <br /> Associates, Inc. (Ash Creek) on behalf of NuStar Terminals Operating Partnership L.P. (NuStar) <br /> for the NuStar Terminals Stockton Facility located at 2941 Navy Drive in Stockton (Site). <br /> Groundwater monitoring at the Site is conducted pursuant to Monitoring and Reporting Program <br /> No. R5-2007-0818 (MRP). <br /> NuStar and its predecessor have conducted monitoring at the Site since 1992. Groundwater <br /> bearing strata underlying the Site have been subdivided into four progressively deeper units <br /> designated zones A through D by NuStar's predecessors and other responsible parties at <br /> neighboring sites. Based on an investigation NuStar conducted during the Fall of 2008, however, <br /> NuStar revised the zone designations and no longer includes a B-zone isoconcentration map of <br /> constituents of concern (CDCs) in the quarterly reports. <br /> During the third quarter of 2010, depth to groundwater varied from about four to 11 feet below <br /> ground surface (bgs) and generally flowed to the south-southeast. Measured vertical hydraulic <br /> gradients were mostly downward. No separate phase product (SPH) was observed during the third <br /> quarter. Laboratory analytical results are summarized in Table 5. The laboratory reports in <br /> Appendix E shows that laboratory analysis for TPHd was conducted both with and without silica gel <br /> cleanup. Table 5 includes the results of analyses performed without the cleanup procedure. <br /> The last observation of SPH occurred in PS/MW-14 in 2007. ST/MW-1, which typically contains the <br /> highest concentrations of petroleum hydrocarbons, was non-detect (ND) during the third quarter for <br /> total petroleum hydrocarbons as gasoline (TPHg) and TPH as diesel (TPHd). However, the <br /> laboratory reporting limits for this sample for TPHg and TPHd were increased dramatically to <br /> 50,000 pg/L and 1,500 pg/L, respectively. The maximum concentrations of TPHg and TPHd were <br /> observed in PS/P-12 and PS/MW-14 at 38,000 micrograms per liter (pg/L) and 9,500 pg/L, <br /> respectively. ST/MW-1 contained the highest concentrations of methyl tertiary butyl ether (MTBE) <br /> at 220,000 pg/L and tertiary-amyl methyl ether (TAME) at 760 pg/L. These results are consistent <br /> with historical results. The highest concentrations of benzene, toluene, ethylbenzene, and total <br /> xylenes (BTEX) were also distributed among ST/MW-1, PS/P-12 and PS/MW-14. These wells are <br /> California Environmental Protection Agency <br /> Z�Recycled Paper <br />