Laserfiche WebLink
SECOR VAVW.secor.com <br /> INTERNATIONAL_ 3017 Kilgore Road,Suite 100 <br /> S E INCORPORATED Rancho Cordova,CA 95670 <br /> 916-861-0400 TEL <br /> 916-861-0430, FAX <br /> May 9, 2006 <br /> Mr. James Barton <br /> Central Valley Regional Water Quality Control Board <br /> 11020 Sun Center Drive, Suite 200 <br /> Rancho Cordova, CA 95670-6114 <br /> RE: Results of Oxygen Injection Feasibility.Pilot Study <br /> 7-Eleven Store#14117 <br /> 2725 Country Club Boulevard <br /> Stockton, California 95204-3937 <br /> SECOR Project No.: 77EL.14117.06.0539 <br /> Dear Mr. Barton: <br /> SECOR International Incorporated (SECOR) on behalf of 7-Eleven presents the analytical <br /> results of groundwater samples collected at 7-Eleven Store #14117 located at 2725 <br /> Country Club Boulevard, Stockton, California (Figures 1 and 2). Groundwater samples <br /> were collected as outlined in the Field Test Program for Evaluation of Oxidation Capacity of <br /> Groundwater submitted to the Regional Water Quality Control Board (RWQCB) in July 22, <br /> .2004._Specifically,..this:letter presents the results of the Pilot Study phase of the evaluation. <br /> Work conducted during the Pilot Study phase-was approved-by the-RWQCB`-in a letter <br /> dated October-17.,.2005..(Attachment.A).- <br /> REVIEW OF GENERAL PROJECT APPROACH <br /> Oxygen injection is utilized as a remedial method to enhance biodegradation of dissolved <br /> petroleum hydrocarbons. However, the RWQCB has indicated concern that injection of <br /> oxygen into groundwater may promote oxidation of dissolved constituents and/or oxidation <br /> of the aquifer lithologies and impact water quality through production of oxidized species, <br /> e.g., Cr207 2 or Cr0 -2, both forms of Cr+6 stable in aqueous environments and which are <br /> considered a health hazard. In addition, oxidation of dissolved constituents may promote <br /> formation of insoluble precipitates, e.g., Fe00:H,that impair aquifer characteristics and foul <br /> well screens. <br /> Reaction of groundwater and aquifer lithologies with injected oxygen is minor due to the <br /> capacity of the dissolved oxygen to remain at high concentrations and the limited radius of <br /> influence as it migrates outward from the injection well through the aquifer. The aquifer <br /> would also tend to buffer the oxidation reactions such that reaction products would be <br /> transient and, following cessation of oxygen injection, the groundwater and aquifer <br /> lithologies would return,to the initial pre-injection equilibrium state, i.e., oxidation reaction <br /> products would tend to revert back to the unoxidized species present in the aquifer at <br /> equilibrium. <br /> 14117 02 Pilot Study Report 04-18-06.doc <br />