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U-. <br /> EDM Nu G.BROWN JR. <br /> ownZe�, GOVERNDR <br /> MG . opDRI0UE2ONWater Boards ENNU. TL <br /> FNUTECTIUt. <br /> Central Valley Regional Water Quality Control Board <br /> TO: Dane S. Johnson3l6 <br /> Senior Geologist "' JJ <br /> P.G. No. 4239 <br /> FROM: C. Dean Hubbard <br /> Engineering Geologis <br /> i6A_�� <br /> P.G .No. 6357 <br /> DATE: 2 April 2014 <br /> SUBJECT: REVIEW OF NO FURTHER ACTION REQUIRED REQUEST, HISTORICAL <br /> CRUDE OIL PIPELINES, US CAN -WELTY ROAD, VERNALIS, SAN <br /> JOAQUIN COUNTY <br /> Chevron Environmental Management Company's (Chevron) consultant submitted a request for No <br /> Further Action Required(NFAR; Report), dated 24 September 2013 for the US Can-Welty Road <br /> project (Site). The Report summarizes various investigations in support of the NFAR for the <br /> historical Tidewater Associated Oil Company (TAOC) and Old Valley Pipeline (OVP) US Can-Welty <br /> Road crude oil pipelines project. The Site is located at the intersection of Welty Road and <br /> California State Highway 33, south of the rural community of Vernalis, San Joaquin County. <br /> The Report summarizes results of soil and groundwater investigations including a human health <br /> and ecological screening evaluation. Based on the findings of the investigations completed by <br /> Chevron, the US Can-Welty Road site qualifies for an NFAR determination. <br /> Background <br /> The Site is in a mixed agricultural, rural residential, light commercial and industrial area. In addition <br /> to the US Can property, the Site is located along the historical TAOC and OVP crude oil pipeline <br /> alignment. The pipelines are located within the Union Pacific Railroad (UPRR) easement which is <br /> on the west side of California State Highway 33. The trace of the former pipelines ran in a <br /> northwest-southeast direction. The TAOC and OVP pipelines, constructed in the early 1900s, were <br /> used for transporting heated crude oil between Central Valley oil fields and Bay Area refineries until <br /> the 1970s. <br /> Soil and poor quality shallow groundwater at the Site have been impacted by crude oil leaks <br /> associated with the historical TAOC and/or OVP crude oil pipelines. Site assessments have <br /> delineated on-site soil and groundwater impacts. The off-site groundwater impacts are delineated <br /> at about 150 to 250 feet from the approximate alignment of the former pipelines. <br /> Subsurface investigations, conducted between 1995 and 2010, have defined the lateral limits of <br /> total petroleum hydrocarbons (TPH) compounds in soil in three areas within a larger area of <br /> affected groundwater. Fuel fingerprint analysis determined that the TPH detected is consistent with <br /> weathered San Joaquin Valley crude oil. For the most part, residual petroleum hydrocarbons (as <br /> degraded crude oil) are described primarily on-site, extending off-site (cross- and down-gradient) to <br /> KARL E. LONCLEY SCD, P.E., CHAIR I PAMELA C. CREEDON P.E., BCEE, EXECUTIVE Orr-ICER <br /> 1685 E Street,Fresno.CA 93706 1 www.waterboards.ca.gov/centralvalley <br /> Cw'J REDVDLED PAPER <br />