ARCHIVED REPORTS_XR0008006 - Laserfiche WebLink

Home Browse Search

<L %'J California Regional Water Quality Control Board Central Valley Region ' Robert Schneider Chair Terry Tamminen Arnold Schwarzenegger Secretary for Sacramento Main Office Governor Environments] lntanet Address httpJ/www swmb.aa govH"&5 RECEIVE[ i Protection 11020 Sun Center Dnvo#200 Rancho Cordova,CA 95670-6114 Phone(916)464-3291 OCT Q $ 1004 a October 2004 i Mr Bob Hopkins Mr ray Allen Union Oil Company of California Stone Brothers Management Company 276 Tank Farm Road 1024 W Robinhood Dr. P O Box 1069 Stockton,CA 95207 San Luis Obispo,CA 93406 l� LETTER REQUEST, CLEANUP AND ABATEMENT ORDER (CAO)NO. 5-00-70Zi-FORMER UNOCAL STATION#5098 AT 5606 PACIFIC AVENUE,AND FORMER MONTGOMERY WARDS AUTO SERVICE AT 5400 PACIFIC AVENUE,STOC%TON,SAN JOA 9 UIN CO UNTY, j Regional Board staff reviewed the 15 September 2004 Request for Extension to Restart SVE System and Evaluation of Potential Enhancement to SVE System (Letter), submitted by Unocal The Letter proposes a date of 15 January 2005 for submitting a report reconrnnending a proposal for enhancement to the existing SVEiAS system,to help cease plume movement 10 Background My letter dated 15 May 2004 requested a Workplan by 15 June 2004,to comply with CAO No 5-00-707,Order No 15, which states "If groundwater monitoring indicates that the groundwater plume has migrated beyond laterally or vertically defined limits during the quarter, the quarterly report shall include a workplan and schedule, with work to begin within 30 days of a report submittal, to define the new plume limits and cease plume movement The Workplan,received 15 June 2004, did not include a schedule to begin work to redefining the limits of the groundwater plume within 30 days A Notice of Violation(NOV) for CAO No 5-00-707 was issued on 18 June 2004 The NOV required implementation of the approved Workplan by 15 July 2004, and also required submittal of a Report by 1 August 2004, showing the steps taken to.cease plume movement You did comply with both NOV deadlines by installing the monitoring wells and providing the Report,which redefined the limits of the groundwater plume and began the process for restarting the SVE/Air S system. On 14 June 2004 the Air S ar AS system was overhauled and restarted The SVE PargmB Y � P i?�g( ) Y system required anew air permit, and was scheduled to start by 15 September 2004 The Soil Vapor Extraction (SVE) system was restarted on 28 September 2004,per email notification received from your consultant ENSR International Inc (ENSR) Additionally,in a phone discussion on 3 September 2004,ENSR proposed enhancing the SVE/AS remediation by In-Situ Chemical Oxidation, specifically Ozone Injection Since additional time would be required to evaluate an injection of an In-Situ Chemical Oxidation substance,I suggested that ENSR begin the process by providing a baseline analysis using site soil and groundwater,prior to submitting a Workplan for a bench scale testing for ozone uijection A pilot study for ozone injection into the aquifer would also be necessary ENSR provided email copies of the preliminary baseline analyses on 28 September 2004 I concur to the proposed 15 January 2005 deadline to provide a Report of the assessment of SVE/AS enhancement,provided the following due dates are met -0—By-15 October-2004 Tsubmit a-Workplan outlining-the entire process-for-enhancement to-the existing— SVE/AS xisting SVE/AS P cease plume s stern,to het movement Also,I have reviewed existing data and request i0 Y inclusion of additional monitoring wells needed to enhance the vertical and lateral extent of contaminants Specifically, adequate characterization is needed to show groundwater flow direction and California Environmental Protection Agency eA Recyckd Paper