Laserfiche WebLink
California Regional Water Quality Control Board <br /> Central Valley Region A <br /> Robert Schneider,Chair <br /> Terry Tarnminen Fresno Office Arnold Schwarz oer <br /> Secretary for 1685 E Street,Fresno,California 93706-2020 Governor <br /> Environmental Phone(559)445-5116•FAX(559)445-5910 <br /> Protection Internet Address: http://www.swrcb.ca.gov/—rwgcb5 <br /> 4 December 2003 RECEIVE <br /> DEC 0 8 2003 <br /> r <br /> Mom ErlNmroar w Mennem"Co. <br /> Mr. M. Scott Mansholt <br /> ChevronTexaco <br /> Chevron Environmental Management Company <br /> P.O. Box 6012 <br /> San Ramon, California 94583-2324 <br /> OFFSITE SOIL AND GROUNDWATER INVESTIGATION, U. S. CANIWELTY ROAD, <br /> VERNALIS,SAN JOAQUIN COUNTY <br /> We have reviewed the 14 November 2003 Offsite Soil and Groundwater Investigation, US CanlWelty Roa, <br /> site, 35275 Welty Road, Vernalis, San Joaquin County, submitted by your consultant, Geomatrix <br /> Consultants, Inc. (Geomatrix). Additionally, we reviewed previous soil and groundwater investigation <br /> reports conducted by Geomatrix and others from 1995 to 2002. The purpose of the investigations was to <br /> determine the lateral and vertical extent of impacts to soil and groundwater caused by petroleum <br /> hydrocarbon leaks from abandoned crude oil pipelines (Old Valley Pipeline, OVP). <br /> The OVP was formerly operated by predecessors of Chevron and Texaco (now ChevronTexaco), from the <br /> early 1900s to the 1970s. The former OVP, present between the northeastern property boundary and <br /> Highway 33, transmitted heavy crude oil from Kern County to the Bay Area. A Kinder Morgan Energy <br /> Partners, L. P., petroleum product pipeline that reportedly transports gasoline,jet fuel, and diesel is located <br /> between the site and State Highway 33. <br /> According to the reports, residual petroleum hydrocarbons were found in soil within two areas along the <br /> northeastern site boundary as follows: 1) adjacent to the northeast corner of an existing building, and, 2) <br /> further west in an area used for parking. The vertical extent of total petroleum hydrocarbons as diesel <br /> (TPH-d) in groundwater on-site is estimated to be similar to the vertical extent of affected soil (between <br /> 55 and 89 feet in GMX-8) within the northeastern areas of affected soil. <br /> Historically, and during the current investigation, a petroleum sheen has been observed in two on-site <br /> monitoring wells, low concentrations of petroleum hydrocarbons were present in a third well, and TPH <br /> compounds were not detected in the fourth (upgradient) on-site monitoring well. Depth to groundwater <br /> at the site is approximately 30 to 35-feet and the gradient is generally northeast. <br /> California Environmental Protection Agency <br /> �3 Recycled Paper <br />