Laserfiche WebLink
` 14 California -Degional Water Quality Con#1 Board <br /> Central Valley Region <br /> Karl E. Longley,SCD, P.E.,Chair <br /> Linda S.Adams Arnold <br /> Secretary for 1655E Street45-51,Fresno,Cal(559)445 591 0 Schwarzenegger <br /> Environmental (559)445 5 t 16•Fax(559)445-5910 Governor <br /> Protection httpa/www.waterboards.ca.gov/centralvalley <br /> 6 August 2009 pp9 <br /> M. Scott Mansholt <br /> Chevron Environmental Management Company PERM <br /> 6111 Bollinger Canyon Road <br /> Rm 3432 <br /> San Ramon, CA 94583 <br /> NO FURTHER ACTION REQUIRED, MOUNTAIN HOUSE DEVELOPMENT SITE #5, BYRON <br /> ROAD, MOUNTAIN HOUSE <br /> Chevron Environmental Management Company (Chevron) submitted a request for No Further <br /> Action Required (NFAR) determination for Mountain House Development Site #5 (Site). The <br /> NFAR, dated 25 November 2008, was prepared by Science Applications International <br /> Corporation (SAIC) on behalf of Chevron. In addition, an Environmental Risk Screening <br /> Evaluation (ERE), dated 15 September 2008, prepared by SAIC was previously submitted. <br /> The Site is along West Byron Road approximately 3,000 feet northwest of the Mountain House <br /> Creek crossing and 500 feet northwest of Mountain House Development Site #4, northwest of <br /> Tracy, in western San Joaquin County. <br /> Central Valley Regional Water Quality Control Board (Central Valley Water Board) staff has <br /> reviewed the NFAR and ERE reports and comments are contained in the attached <br /> memorandum. In a letter dated 18 March 2009, Central Valley Water Board staff concurred <br /> that soil and groundwater affected by crude oil leaks from Chevron's historical Old Valley <br /> Pipeline (OVP) and Tidewater Associated Oil Company pipelines had been adequately <br /> delineated and additional characterization was not needed. There are no monitoring wells to <br /> be destroyed. <br /> According to the findings, affected soil and groundwater are limited in extent to an area within <br /> the West Byron Road right-of-way (ROW) easement and a utility corridor. The historical <br /> pipelines lie within the highway easement and the utility corridor. <br /> The future use and Site access is anticipated to be limited to construction/maintenance <br /> activities associated with the West Byron Road easement and utility corridor. According to the <br /> August 2008 ERE, and considering that the Site use is not anticipated to change, SAIC <br /> conducted the human health risk evaluation. The evaluation was based on the most likely <br /> potential exposure of a construction/trench maintenance worker associated with features <br /> within the road ROW and utility corridor. Based on the risk evaluation, SAIC concluded that <br /> the residual crude oil remaining at the Site does not pose a threat to human health for the <br /> construction/trench worker scenario. <br /> California Environmental Protection Agency <br /> :tea Recycled Paper <br />