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Californiagional Water Quality Cfrol Board f <br /> Central Valley Region (;a „ <br /> v Katherine Hart, Chair <br /> Linda S. Adams Edmund G.Brown Jr. <br /> Actin Secretary for 11020 Sun Center Drive#200, Rancho Cordova, California 95670-6114 Governor <br /> 9 (916)464-3291 •FAX(916)464-4645 <br /> Environmental http://www.waterboards,ca.9ov/centralvalley <br /> Protection <br /> 15 February 201 Ito <br /> Mr. Kevin E. Dyer <br /> Shell Oil Products US FEg 1'1 2011 <br /> 17 Junction Drive, PMB #399 HEAUT6 <br /> Glen Carbon, IL 62034 SNVIppNMeWPl- CES <br /> pERMITISER <br /> SITE ASSESSMENT WORK PLAN, FORMER SHELL CENTRAL VALLEY CRUDE <br /> OIL PIPELINES, HANSEN ROAD NEAR SCHULTE ROAD, TRACY, SAN JOAQUIN <br /> COUNTY <br /> California Regional Water Quality Control Board, Central Valley Region (Central Valley <br /> Water Board) staff reviewed the 17 January 2011 Site Assessment Work Plan (Work <br /> Plan) for the Former Shell Central Valley Crude Oil Pipeline at Hansen Road near <br /> Schulte Road in Tracy (Site) on behalf of Equilon Enterprises LLC doing business as <br /> Shell Oil Products US (Shell). <br /> The Work Plan proposes additional soil and groundwater investigation to complete the <br /> delineation of total petroleum hydrocarbons detected during and subsequent to an <br /> investigation conducted between 12 July and 23 August 2010. Shell's 15 October 2010 <br /> Site Investigation Report (Investigation Report) described the results of the drilling, soil <br /> sampling, monitoring well installation, and groundwater sampling of 13 well borings <br /> (MW-1 through MW-4, MW-5A, MW-5B, MW-5C, and MW-6 through MW-11) installed <br /> along the northwest alignment of the pipeline during this investigation. The Central <br /> Valley Water Board staff's 5 November 2010 letter provided comments on the <br /> Investigation Report. <br /> Our 5 November letter requested that Shell submit a remedial investigation work plan to <br /> (1) delineate the lateral extents in the Trench 2 and 3 areas, including the depth <br /> discrete groundwater sampling proposed in a 2009 work plan, (2) characterize <br /> contaminated soil observed in borings MW-1 , MW-2, MW-4 and MW-5A in terms of the <br /> potential to further degrade groundwater and propose cleanup, as necessary, and <br /> (3) propose the installation of permanent soil vapor probes near the highest levels of <br /> soil and groundwater contamination to facilitate additional soil vapor sampling and <br /> modeling to calculate soil vapor cleanup levels. <br /> The Work Plan provides responses to our 5 November letter. In it, Shell clarifies that (1) <br /> there was no intent to sample water supply wells 7 and 4 (well 7 is inactive and well 4 is <br /> 2,300 feet upgradient of the Site), (2) laboratory analytical data for the analysis of <br /> physical soil properties are presented in Appendix G of the Investigation Report, <br /> (3) further soil delineation is needed near wells MW-1, MW-2, and MW-4, but not near <br /> MW-5A, (4) delineation of the lateral extent of groundwater pollution around the <br /> Trench 2 and 3 areas is needed, (5) depth discrete groundwater sampling was not <br /> proposed in the 2009 work plan and should not be conducted to avoid spreading <br /> California Environmental Protection Agency <br /> %DRecycled Paper <br />