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EDMUND G. BROWN JH. 3.i,4♦' GOVERNOR C A L I I O N M I• MATTHEW RODHIDUEZ WOOF' SEGRE*AHY FOR Water Boards ENVIHONMENIAL PHOrEG1iO14 Central Valley Regional Water Quality Control Board FACT SHEET PROPOSED NO FURTHER ACTION REQUIRED, FORMER VERNALIS PUMP STATION, HISTORICAL CRUDE OIL PIPELINES, VERNALIS, STANISLAUS AND SAN JOAQUIN COUNTIES This Fact Sheet is to inform interested parties of the Central Valley Regional Water Quality Control Board's (Central Valley Water Board) consideration of No Further Action Required for the Chevron Environmental Management Company (Chevron) project (Site), and to request comments on the proposed action. The Site location is noted on the enclosed Figure. From the early 1900's to the late 1960's, predecessors of Chevron, Old Valley Pipeline (OVP) and Tidewater Associated Oil Company (TAOC), utilized the historical pipelines and associated pump station to transport crude oil from Kern County to San Francisco area refineries. Use of the historical pipelines/pump station was terminated by the early 1970's. The former pump station and historical pipelines, Union Pacific Railroad (UPRR) tracks and California State Highway 33 run through the approximate center of the project. The historical pipelines and/or pump station equipment leaked and non-hazardous crude oil affected soil and groundwater is present beneath the pipelines, portions of the former pump station property, Highway 33, some properties to the east, and the UPRR tracks. From the late 1990's to 2010, borings were drilled and soil and groundwater samples collected for analysis by a California certified analytical laboratory. An analytical laboratory fuel fingerprint evaluation determined that the petroleum hydrocarbons present are attributable to weathered San Joaquin Valley crude oil. According to the site investigations, the residual crude oil is present in soil near the center of the project, primarily beneath the historical TAOC and OVP pipelines, Highway 33, and the UPRR tracks. Findings in the consultants' reports indicated crude oil affected soil with approximate dimensions measuring about 275 feet by 750 feet, generally parallel to the historical pipelines and Highway 33. Depth to groundwater is approximately 40 feet below ground surface. The lateral extent of affected groundwater has been defined and is slightly larger than the area of affected soil. Five onsite groundwater wells were destroyed in 2009 in accordance with respective County guidelines. Chevron's consultant reviewed the California Natural Diversity Database maintained by California Department of Fish and Game for nearby ecological receptors. The query did not identify threatened, endangered, or sensitive species within one mile of the Site. According to Chevron's 24 May 2011 request, crude oil affected soil and groundwater has been delineated at the Site and the project is a candidate for no further action consideration. Chevron's consultant completed a Human Health Risk Assessment (HHSE) dated September 2010, using a conservative risk exposure scenario to residual crude oil in soil and groundwater. The HHSE utilized a residential approach using a hypothetical future onsite resident. The most likely future use of the Site will be for commercial/industrial purposes. Shallow groundwater is unlikely to be used as a drinking water source, thus exposure to groundwater was not evaluated quantitatively for the HHSE. KARL E. LONGLEY SCD, P.E., CHAIR I PAMELA C. CREEDON, EXECUTIVE OFFICER 1685 E Street,Fresno,CA 93706 I www.waterboard$.Ca.gOv/centralvalley `,RECYCLED PAPER