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California0egional Water Quality Co4oDl Board <br /> Central Valley Region ' <br /> A e� <br /> Karl E. Longley,ScD, P.E.,Chair <br /> Linda S.Adams Arnold <br /> 1685 E Street,Fresno,California 93706 C <br /> Secretaryfor phone 559 445 5116 FAX(559 445-5910 L! if 1 <br /> gr!�g er <br /> Environmental ) � <br /> Protection http,/lwww.waterboards.ca.govlcentralvalley <br /> OCT 2 2008 <br /> TO: Clay Rodgers FROM: C. Deaf Hubba4VRONMENT HEALTH <br /> Senior Engineering Geologist Engineers eol86f9f'1lT/SERVICES <br /> P. G. N . 63 7 <br /> SIGNATURE: <br /> Sheiton R. Gray <br /> DATE: 30 September 2008 Seni Engineering Geologist <br /> SIGNATURE <br /> SUBJECT: CONSIDERATION OF REQUEST FOR NO FURTHER ACTION REQUIRED <br /> DETERMINATION, MOUNTAIN HOUSE DEVELOPMENT SITE #2, BYRON <br /> ROAD, MOUNTAIN HOUSE, SAN JOAQUIN COUNTY <br /> Rationale: Crude oil-affected soil and groundwater has been delineated, is of limited extent <br /> within an area of approximately 75 by 100 feet, and is defined vertically by samples that did <br /> not contain detectable concentrations of petroleum hydrocarbons from an approximate <br /> depth of 44 feet. The area of affected soil and groundwater are located beneath the Byron <br /> Road right-of-way (ROW) easement. The future site use is anticipated to continue as the <br /> highway ROW. An environmental risk screening evaluation (ERE) completed in 2007, <br /> considered a construction/trench maintenance worker the most likely potential future <br /> exposure. Based on Screening for Environmental Concerns at Sites with Contaminated <br /> Soil and Groundwater, Interim Final, San Francisco Regional Water Quality Control Board, <br /> February 2005, residual crude oil concentrations remaining at the site are below <br /> environmental screening levels (ESLs) for a construction/trench worker scenario. <br /> Consistent with State Water Resources Control Board (SWRCB) Resolution No. 92-49, <br /> Section IIIA through C, Science Applications International Corporation (SAIC) evaluated <br /> alternative cleanup technologies and found that technologies other than natural attenuation <br /> would be ineffective, infeasible, and costly since the affected area is beneath Byron Road. <br /> Issues: In 2001, crude oil-affected soil and groundwater was discovered in the vicinity of two <br /> historical Old Valley Pipelines that cross the property. The pipelines were utilized by <br /> Chevron predecessors to transport crude oil from Kern County oil fields to refineries in the <br /> San Francisco Bay area. The affected soil impacts consisted primarily of total petroleum <br /> hydrocarbons as crude oil (TPHc) which may contain polynuclear aromatic hydrocarbons <br /> (PAHs) and benzene, toluene, ethylbenzene, and xylenes (BTEX). Soil and groundwater <br /> affected by crude oil have been adequately delineated. <br /> Setting: Rural agricultural with some nearby residential properties under development. <br /> California Environmental Protection Agency <br /> Recycled Paper <br />