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4-117 CaliforniWegional Water Quality Cool Board <br /> r�%j Q6; Central Valley Region <br /> Karl E. Longley,SCD,P.E.,Chair <br /> Linda S.Adams Arnold <br /> 1685 E Street,Fresno,California 93706 Secretaryfor Phone(559)445-51 Ib•FAX(559)445-5910 Schwnegger <br /> Environmental Governor <br /> Protection httpa/www.waterboards.ca.gov/rentralvalley <br /> TO: Clay Rodgers FROM: C. Dean Hubbard <br /> Senior Engineering Geologist Engineering Geologist <br /> P. G. No. 57 <br /> SIGNATURE: <br /> Shelton R. Gray <br /> DATE: 5 May 2009 Seni ngineering Geologist <br /> SIGNATURE: , C7 <br /> SUBJECT: CONSIDERATION OF REQUEST FOR NO FURTHER ACTION REQUIRED <br /> DETERMINATION, MOUNTAIN HOUSE DEVELOPMENT SITE #4 (SITE), <br /> BYRON 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 100 by 125 feet, and is defined vertically by a sample that <br /> did not contain detectable concentrations of petroleum hydrocarbons from an approximate <br /> depth of 44 feet below ground surface (bgs). The area of affected soil and groundwater is <br /> beneath the Byron Road right-of-way (ROW) easement. The future Site use is anticipated <br /> to continue as the highway ROW. An environmental risk screening evaluation (ERE) <br /> completed in 2008, considered a construction/trench maintenance worker scenario the <br /> most likely potential future exposure. Based on Screening for Environmental Concerns at <br /> Sites with Contaminated Soil and Groundwater, Interim Final, San Francisco Regional <br /> Water Quality Control Board, May 2008, residual crude oil concentrations remaining at the <br /> Site are below environmental screening levels (ESLs) for a construction/trench worker <br /> 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 (OVP) that cross the property. The historical pipelines were <br /> utilized by Chevron predecessors to transport crude oil from Kern County oil fields to <br /> refineries in the San Francisco Bay area. The affected soil impacts consist primarily of <br /> total petroleum hydrocarbons as crude oil (TPHc) which may contain polynuclear aromatic <br /> hydrocarbons (PAHs) and benzene, toluene, ethylbenzene, and xylenes (BTEX). Soil and <br /> groundwater affected by crude oil have been delineated. <br /> Setting: Rural agricultural with some nearby residential properties under development. <br /> California Environmental Protection Agency <br /> cl?Recycled Paper <br />