SITE INFORMATION AND CORRESPONDENCE

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Mr. Jeff Baker -2 - 10 46 June 2011 Stockton Terminals Technical�ommittee During the first quarter 2011, the highest dissolved COC concentrations occurred in A zone wells in the BP/ARCO aboveground tank (AGT) area and in the southeast corner of the Tesoro property. In the deeper zones, maximum COC concentrations were encountered on the Tesoro property in TS/MW-3D. MBAS concentrations were below the water quality objective of 500 micrograms per liter (pg/L) in 31 of the 44 wells sampled. Measurable liquid phase hydrocarbons (LPH also known as "free product') were not observed in any wells during the first quarter, but an LPH sheen was observed in TS/M-2, TS-5R, and TS-4R. These observations are consistent with historical monitoring results. Our comments are: 1. Central Valley Water Board staff concur with the STTCs recommendation to discontinue MBAS and diethylene glycol monobutyl ether (DGME) analysis and well over purging activities associated with the 2008 fire foam release. You may immediately discontinue these activities. 2. Central Valley Water Board staff reviewed the Site data and prepared the attached revised draft MRP. Changes in the sampling schedule are noted in bold in Table 1 of the revised draft MRP. If a well has met the criteria for fuel oxygenate sampling it may be eliminated from the requirement as outlined in Footnote 3 on Table 1 of the revised draft MRP. By 11 July 2011, the STTC needs to review the revised draft MRP and submit comments. 3. During the 13 May 2011 meeting, BP/ARCO informed Central Valley Water Board staff that the facility had been sold to Buckeye Partners, L.P. (Buckeye). By 30 June 3011, Buckeye needs to send Board staff the appropriate billing contact information so that Board staff can send a cost recovery agreement. 4. In December 2010, FTOC and Tesoro abandoned 18 monitoring wells with faulty seals. Five additional well abandonments are scheduled, but were delayed due to weather. Central Valley Water Board staff requested that 15 of the 23 abandoned wells be replaced. By 1 August 2011, FTOC and Tesoro need to complete the well abandonments, install the replacement wells, and submit a report of findings. 5. In March 2011, Tesoro concluded a one-year hydrogen peroxide injection pilot study to address free product at the southwest property boundary shared with FTOC in the vicinity of TS-413. By 30 June 2011, Tesoro needs to submit the results of the pilot study. The report needs to include the baseline and monthly monitoring data along with recommendations for additional work, if appropriate. 6. On 25 January 2011, Tesoro installed Waterloo Emitters in wells TS/MW-3DR and TS/MW-4D and began a one-year oxygen injection pilot study to reduce the concentrations of benzene, TPHg, and TPHd in the D zone. Baseline groundwater monitoring was conducted for dissolved oxygen/ oxidation-reduction potential and biodegradation parameters during November and December 2010.