Laserfiche WebLink
e <br /> -24% Californioegional Water Quality Cobol Board <br /> Central Valley Region <br /> Karl E. Longley,StD,PE, Chair <br /> Linda S. Adams Arnold <br /> 5ecrelmyfor Fresno Branch Office Arnold <br /> EnvironnrenPa! 1685 E Street,Fresno,California 93706 Governor <br /> Protection (559)445-5116• Fax(559)445-5910 <br /> httpalwww.waterboards,ca.gov/centralvalley <br /> IRECEPED <br /> 27 September 2007 SEP 2 8 2007 <br /> ENVIRONivIU1T HEALTH <br /> M. Scott Mansholt PE91MITYSE19VICES <br /> Chevron Environmental Management Company <br /> 6001 Bollinger Canyon Road <br /> Rm K2066 <br /> San Ramon, CA 94583-2324 <br /> REVIEW OF SOIL AND GROUNDWATER INVESTIGATION, MOUNTAIN HOUSE <br /> DEVELOPMENT SITE #5, MOUNTAIN HOUSE, SAN JOAQUIN COUNTY <br /> Regional Water Board staff has reviewed the referenced report, dated 18 September 2007 <br /> prepared for Chevron by Science Applications International Corporation (SAIC). The project is <br /> located between the former Old Valley Pipeline (OVP) and the Tidewater Associated Oil <br /> Company (TAOC) rights-of-way adjacent to Byron Road, respectively to the northeast and <br /> southwest. The TAOC line is located within the Union Pacific Railroad (UPRR) right-of-way <br /> (ROW). <br /> The OVP and TAOC lines previously transported crude oil between Kern County oil fields and <br /> refineries in the Richmond area until the 1970's; the lines were removed from service at that <br /> approximate time. In the 1940's, the pipelines transported Bunker C fuel oil from Richmond to <br /> railroad hubs in Tracy. Two active refined product pipelines are present within the UPRR <br /> ROW. <br /> Additionally, we reviewed other SAIC site investigations and a November 2001 soil and <br /> groundwater investigation completed for Trimark Communities, Inc. by Condor Earth <br /> Technologies. Condor investigation boring GP-64 sample at 16-feet identified impacted soil at <br /> 7,600 mg/kg (milligrams per kilogram) along the former OVP, within the area now identified as <br /> Mountain House Site #5. <br /> We previously concurred, that based on the prior investigations, impacted soil had been <br /> adequately delineated. The affected soil area was limited in extent, had approximate lateral <br /> dimensions of 100 by 150-feet and less than 32-feet vertically, and was located beneath Byron <br /> Road, the UPRR right-of-way, and the existing active pipelines. <br /> The purpose of the current investigation was to delineate the extent of impacted groundwater <br /> downgradient of the site as reported by other SAIC investigative borings. Previous boring <br /> MW5-7 reported 350 pg/L (micrograms per liter) total petroleum hydrocarbons as diesel <br /> (TPHd) in groundwater and additional work was needed. <br /> California Environmental Protection Agency <br /> Ca Recycled Paper <br />