Laserfiche WebLink
Californiaoegional Water Quality Coreol Board <br /> \� Central Valley Region l j <br /> Arnold <br /> Linda S.Adams <br /> Secretaryfor Sacramento Main Office Schwarzenegger <br /> F_nvironmenia/ 11020 Sun Center Drive#200,Rancho Cordova,California 95670-6114 Governor <br /> Protection Phone(916)464-3291 •FAX(916)464-4645 <br /> http://www.walerboards.ca.gov/centralvalley <br /> G3G�C��B�I�D <br /> 23 October 2007 NOV ® 7 2007 <br /> ENONENT <br /> Mr. Ed Ralston KIRMITISERViCESjH <br /> ConocoPhillips <br /> 76 Broadway <br /> Sacramento, CA 95818 <br /> MONITORING REPORTS, FORMER UNOCAL BULK PLANT NO. 0788, 8203 EAST <br /> ELEVENTH STREET, TRACY, SAN JOAQUIN COUNTY <br /> California Regional Water Quality Control Board, Central Valley Region (Regional Water <br /> Board) staff reviewed the: <br /> • 29 January 2007 Quarterly Summary Report— Fourth Quarter 2006 (Fourth QMR) <br /> 25 April 2007 Quarterly Summary Report— First Quarter 2007 (First QMR) <br /> • 14 May 2007 Sampling of Domestic Irrigation Well (Domestic Well Report) <br /> • 1 October 2007 Analytical Sampling Results from 29 August 2007 sampling event <br /> (August Results) <br /> SECOR International Incorporated (SECOR) submitted the documents on behalf of <br /> ConocoPhillips for the former Unocal Bulk Plant No. 0788 at 8203 East Eleventh Street in <br /> Tracy (Site). The Site is a former bulk fuel storage facility in Tracy. In 1918, Unocal <br /> constructed four aboveground tanks (AGTs) in the western portion of the Site. Two <br /> 19,500-gallon AGTs stored diesel fuel and super unleaded gasoline and the remaining two <br /> 20,000-gallon AGTs stored regular leaded gasoline and unleaded gasoline. The AGTs were <br /> removed, and the Site is now vacant. <br /> ConocoPhillips has conducted groundwater monitoring since 1994. The groundwater <br /> monitoring network consists of eight onsite monitoring wells (U-1 through U-8), one onsite <br /> water supply well (WSW-1), and two offsite monitoring wells (U-9 and U-10). <br /> The Fourth QMR describes the fourth quarter 2006 groundwater monitoring performed in <br /> October 2006. Groundwater flow was to the north-northwest, and the depth to groundwater <br /> was about nine feet below ground surface (bgs). TPHd was at the highest concentration ever <br /> detected in wells U-8 and U-9 at 280 micrograms per liter (pg/L) and 630 pg/L, respectively. <br /> The laboratory flagged these data indicating that the surrogate recovery for TPHd was not <br /> within the control limits. No other petroleum hydrocarbons were detected. <br /> The First QMR describes the first quarter 2007 groundwater monitoring performed in <br /> January 2007. Groundwater flow was to the northwest, and the depth to groundwater was <br /> California Environmental Protection Agency <br /> Qd Recycled Paper <br />