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California "t-gional Water Quality Contr3oard OF.QU; Central Valley Region !Linda S.AdamsKarl E. Longley,ScD, P.E.,Chair.1'ecvernrn for Sacramento Main Office ,Arnold
<br /> Env,ronn,enmi 11020 Sun Center Drive 9200.Rancho Cordova.Calirnmo, 9567p6114 Schwarzenegger
<br /> Proreerlon Phone(916)464-3291 •FAX(916)461-4645 orwemnr
<br /> hnp.liv,vwwaler6oard,.ca,eovlccntmkal lc
<br /> i
<br /> 25 April 2008
<br /> Mc Jeff Baker q I I
<br /> Tesoro Companies, Inc. ��j� APR 2 9 2008 t
<br /> 3450 South 344 Way, Suite 100
<br /> Auburn, WA 98001-5931 By
<br /> RESPONSE TO COMMENTS, STOCKTON TERMINALS TECHNICAL COMMITTEE
<br /> FACILITIES, PORT OF STOCKTON, SAN JOAQUIN COUNTY
<br /> Regional Water Quality Control Board, Central Valley Region (Regional Water Board) staff
<br /> reviewed the 28 January 2008 Response to RWQCB Letter Dated June 14 2007 (Response).
<br /> SECOR International, Inc. (SECOR) submitted the document on behalf of the Stockton Terminals
<br /> Technical Committee (STTC). STTC is comprised of three bulk fuel facilities at the Port of
<br /> Stockton (Site) including British Petroleum (BP) (formerly ARCO), Tesoro Petroleum Company
<br /> Inc. (Tesoro), and Time Oil Company.
<br /> The principal contaminants of concern (COCs) at the Site include total petroleum hydrocarbons
<br /> as gasoline (TPHg), TPH as diesel (TPHd), benzene, toluene, ethylbenzene, and xylenes
<br /> (BTEX), tertiary amyl methyl ether (TAME), methyl tertiary butyl ether (MTBE), and tertiary butyl
<br /> alcohol (TBA). The Response attributes the off-site migration of petroleum hydrocarbons
<br /> primarily to a 1998 spill at the Tesoro site and steeper pre-1997 horizontal gradients, corrects
<br /> portions of our summary of the first quarter 2007 groundwater monitoring data, and offers
<br /> conclusions regarding the lateral and vertical distribution of COCs emanating from the Site. The
<br /> Response includes concentration plots for select wells that show increasing benzene j
<br /> concentrations in three downgradient, off-site monitoring wells (OW-9C, OW-8D, and OW-3C).
<br /> Despite these increasing concentrations, the Response concludes that groundwater monitoring
<br /> data do not show that that off-site migration of COCs is occurring and offers no immediate
<br /> remedy for the downgradient migration within the C and D water bearing zones.
<br /> Separate phase hydrocarbons (SPH) are typically observed in four on-site monitoring wells
<br /> (AR/MW-12A, TO/MW-1, TS-4, and TS/M-2). STTC has utilized SoakeaseTM SPH removal
<br /> socks in these wells since 20 September 2002 to remove the SPH. On 2 May 2007, STTC
<br /> submitted the Work Plan for Enhanced Bioremediation Study, which proposes injecting a nutrient
<br /> solution to clean up fuel hydrocarbons at the BP Site.
<br /> The STTC conducts monitoring at the Site pursuant to the requirements of Monitoring and
<br /> Reporting Program (MRP) No. R5-2004-0823. SECOR conducted groundwater monitoring and
<br /> sampling for the Second, Third, and Fourth quarterly monitoring reports (QMRs) during April,
<br /> July, and October 2007, respectively. Sediments underlying the Site are subdivided into four
<br /> progressively deeper hydrostratigraphic units referred to as the A Zone, B Zone, C Zone, and D
<br /> Zone. In the Fall of 2004, the STTC began operation of two ozone sparge (OS) systems to clean
<br /> California Environmental Protection Agency
<br /> rZd Reravrled Paper
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