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bE..UNu G. B..­JN. <br /> UUVENNUr: <br /> CAL 1 P O P N 111 MGRHEW Rp DMOUEZ <br /> E <br /> Water Boards <br /> �(�/� EN VIl1UNM6NI wl.HHOTk(:lluN <br /> Central Valley Regional Water Quality Control Board RECEIVE® <br /> 11 March 2014 MAR 13 2014 <br /> Michael Oliphant <br /> Chevron Environmental Management Company ENVIRONMENTAL HEALTH <br /> PERMRISERVICES <br /> 6001 Bollinger Canyon Road <br /> P.O. Box 6012 <br /> San Ramon, CA 94583 <br /> NO FURTHER ACTION REQUIRED, HISTORICAL CRUDE OIL PIPELINES, TRACY RAIL YARD <br /> OFFSITE -WEST AREA, TRACY, SAN JOAQUIN COUNTY <br /> Chevron Environmental Management Company (Chevron) submitted a No Further Action Required <br /> Request Report, dated 28 June 2013. The report summarizes the various investigations and a <br /> human health and ecological screening evaluation (HHESE) in support of the no further action <br /> request for the historical Tidewater Associated Oil Company (TAOC) Tracy Rail Yard Offsite -West <br /> area project (TRY West; Site). The TRY West investigations included a multi-family residential <br /> development, through which the historical TAOC crude oil pipelines alignment crossed the Site. <br /> Chevron is the responsible party for soil/groundwater conditions associated with the historical <br /> TAOC crude oil pipelines. In addition to the residential area, nearby/adjacent land use includes a <br /> City of Tracy Service Center, vacant land and other residential developments. The enclosed <br /> memorandum outlines the closure justification. <br /> Soil and poor quality shallow groundwater at the Site have been impacted by crude oil leaks <br /> associated with the historical TAOC pipelines. Site assessments have delineated the extent of <br /> impacts. Water quality parameters for groundwater at a nearby TAOC site describe concentrations <br /> of total dissolved solids from over 3,000 milligrams per liter (mg/L) up to 27,000 mg/L. A City of <br /> Tracy municipal code prohibits use of the upper groundwater for reasons unrelated to the historical <br /> crude oil pipeline leaks. The petroleum hydrocarbons in soil and groundwater have been shown to <br /> be stable or shrinking and will naturally degrade over time, likely several years. <br /> Chevron submitted a Soil and Groundwater Management Plan (SGMP), dated 29 October 2013, <br /> which provides Chevron contact information if future construction or other site development and/or <br /> improvements encounter crude oil impacted soil or groundwater. Depth to upper groundwater is <br /> about 18 feet below ground surface (bgs) and is not likely to be encountered. Central Valley <br /> Regional Water Quality Control Board staff (Staff) has reviewed the submitted documents and <br /> concurs with the no further action status request. <br /> The HHESE report concluded that the residual crude oil detected in soil and groundwater is limited <br /> in extent and will degrade with time. The HHESE determined that the only constituent of potential <br /> concern in soil was non-carcinogenic and as such, cancer risks were not evaluated. The non- <br /> cancer hazard index (HI) risk for a hypothetical future on-site resident from direct and non-direct <br /> exposure was 1.6E-05, which is well below the HI target level of 1 for the residential scenario. This <br /> non-cancer HI value indicates that potential exposure to on-site soils would not result in a public <br /> health risk. Additionally, Chevron's consultant's review of a California Fish and Game database <br /> indicates a threat to sensitive ecological receptors does not appear to exist. <br /> Knn>_ E. LONGLEv SCD. P.E.. C11AIR I PAMELA C. CnEEDON P.E., BGEE, Ex Ccurivr orncEr <br /> 1685 E Street.Fresno.CA 93706 1 www.wate rboard s.ca.gow central vale ev <br />