Laserfiche WebLink
� California Regional Water Quality ontrol Board .. <br /> e <br /> Central Valley Region <br /> Robert Schneider,Chair <br /> Alan C.Lloyd,Ph.D. Arnold <br /> Secretary for Fresno Branch Office Schwarzenegger <br /> Environmental 1685 E Street,Fresno,California 93706 Governor <br /> Protection (559)445-5116 6 Fax(559)445-5910 <br /> http:/iwww.waterboards.ca.gov/centralvalley <br /> 13 April 2005 <br /> RE IV Eu <br /> M. Scott Mansholt <br /> APR 14 2095 <br /> Chevron Environmental Management Company EN\A2>MEN1 HEALTH <br /> Property Management PERMITISERNACES <br /> 6001 Bollinger Canyon Road <br /> P.O. Box 6012 <br /> San Ramon, CA 94583-0712 <br /> REVIEW OF SOIL SAMPLING AND ANALYSIS WORKPLAN, MOUNTAIN HOUSE SITES #4 <br /> AND #S, MOUNTAIN HOUSE, SAN JOAQUIN COUNTY <br /> We have reviewed the Workplan for Soil and Groundwater Investigation, Mountain House <br /> Development, Mountain House Sites #4 and 45, submitted by Science Applications International <br /> Corporation (SAIC) on behalf of ChevronTexaco. The workplan proposes collecting additional soil and <br /> groundwater samples in the vicinity of crude oil pollution previously identified in two borings completed <br /> by Condor Earth Technologies, Inc. (Condor) at the'site in 2001. According to our files, the initial <br /> discovery of petroleum hydrocarbons in soil and groundwater was confirmed attributable to leaks from <br /> the Old Valley Pipeline (OVP) that had existed on the Mountain House sites. Mountain House Sites 44 <br /> and#5 are located approximately 3,000 and 1,900 feet southeast, respectively of the intersection of <br /> Byron and Kelso Roads, northwest of the City of Tracy, in western San Joaquin County. <br /> During the Condor investigation, elevated concentrations of petroleum hydrocarbons were reported in <br /> soil collected from borings GP-53 and GP-180 at Site#4, and borings GP-64 and GP-183 at Site#5 at <br /> depths ranging from 4 to 16 feet; petroleum hydrocarbons as crude oil (TPHc) concentrations in soil <br /> ranged from 65 to 13,000 mg/kg. Depth to groundwater beneath the sites ranged from 8 to 17 feet. <br /> Condor did not collect groundwater samples for analysis. <br /> ChevronTexaco needs to complete characterization of the lateral and vertical extent of pollution in soil <br /> and groundwater in order to reduce/eliminate and/or identify potential risks to human health and the <br /> environment. Regional Board staff understands that portions of sites are in close proximity to the former <br /> OVP and arc being considered for possible residential and/or commercial retail development. <br /> Consequently, in order to address potential risks to human health and the environment regarding <br /> development, ChevronTexaco should proceed to implement and complete soil and groundwater <br /> characterization activities prior to future site improvements. <br /> California Environmental Protection Agency <br /> co Recycled Paper <br />