Laserfiche WebLink
California Regional Water Quality Control Board ON <br /> Central Valley RegionKatherine Hart,Chair, <br /> Linda S.Adams Arnold <br /> Secretaryfor 11020 Sun Center Drive#200,Rancho Cordova,California 95670.6114 Sehwar[enegger <br /> Enviroawenral Phone(916)464-3291 •FAX(916)464-4645 Governor <br /> Protecdoa hitp.//www.i aterboards.ca.gov/centmlvalley <br /> f <br /> 17 August 2010 RECEIVED - SOP US <br /> AUG ? 0 2010 <br /> Mr. Carol Campagna ENVIROMENTAL SERVICES <br /> Shell Oil Products US WESTERN REGION <br /> 20945 South Wilmington Avenue <br /> Carson, CA 90810 <br /> GROUNDWATER MONITORING AND REMEDIATION REPORT— FIRST AND SECOND <br /> QUARTERS 2010, SHELL STOCKTON TERMINAL, 3515 NAVY DRIVE, STOCKTON, SAN <br /> JOAQUIN COUNTY' <br /> Regional Water Quality Control Board, Central Valley Region (Central Valley Water Board) <br /> staff reviewed the 30 July 2010 Groundwater Monitoring and Remediation Report, First and <br /> Second Quarters 2010 (Semi-annual Report) submitted by Conestoga-Rovers and Associates <br /> (CRA) on behalf of Shell Oil Products US (Shell) for the Shell Stockton Terminal at 3515 Navy <br /> Drive in Stockton (Site). Groundwater monitoring at the Site is conducted pursuant to <br /> Monitoring and Reporting Program (MRP) No. R5-2005-0810. <br /> The Semi-annual Report summarizes groundwater conditions observed at the Site between <br /> February and May 2010. The prevailing horizontal and vertical groundwater gradients are <br /> variable and downward, respectively. No separate phase hydrocarbons (SPH) were observed <br /> in monitoring wells during the first half of 2010. Groundwater pollution at the Site is divided into <br /> three source areas (SAS)designated as SAI, SA2, and SA3. During the first half of 2010, SA2 <br /> well MWA 0 contained the maximum concentrations of total petroleum hydrocarbons as <br /> gasoline (TPHg) and benzene at 33,000 micrograms per liter(ug/L) and 15,000 pg/L, <br /> respectively. SA2 well MW-16 had the highest concentration of TPH as diesel (TPHd) at <br /> 11,000 pg/L, and MW-1, in SAI, contained the highest concentrations of methyl tertiary butyl <br /> ether(MTBE)and tertiary butyl alcohol (TBA) at 16,000 pg/L and 13,000 pg/L, respectively. <br /> Groundwater remediation at the Site is being performed by operating a groundwater extraction <br /> (GWE) system which pumps water from MW-1. The GWE system has been operated since <br /> 10 April 2006. During the first half of 2010, the GWE system treated about 27,000 gallons of <br /> water at an extraction rate that varied between 0.03 gallons per minute (gpm) and 0.2 gpm <br /> and removed about 5 pounds (lbs) of TPHg, 0.5 lbs of benzene, and 1.8 lbs of MTBE. The <br /> system was inoperable during the last half of June 2010. The Semi-annual Report states that <br /> performance of quarterly groundwater monitoring and operation of the GWE will continue. <br /> Shell is currently working on designing and permitting the proposed air sparge/soil vapor <br /> extraction (AS/SVE) system. Our 16 June letter,which commented on Shell's 7 May 2010 Air <br /> Sparge Well and Soil Vapor Extraction Well Installation Work Plan (Work Plan), requested <br /> submission by 2 July 2010 of Shell's sampling and analysis plan for(1)TPHd in influent <br /> vapors and (2) soil samples retained for laboratory analysis during drilling of the AS wells. In <br /> response to this request, Shell submitted a letter dated 1 July which detailed the proposed <br /> California Environmental Protection Agency <br /> ed Recycled Paper <br />