SITE INFORMATION AND CORRESPONDENCE FILE 2

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San Joaquin County Ppu�N Environmental Health Depnartment DIRECTOR �a. c f Donna Heran, REHS a , 600 East Main Street PROGRAM COORDINATORS Stockton, California 95202-3029 `f Robert McClellan, REHS Jeff Carruesco, REHS, RDI Kasey Foley, REHS CQ�ri' R6 Website: www.sjgov.org/ehd Linda Turkatte. REHS Phone: (209) 468-3420 Fax: (209) 464-0138 March 6, 2012 Catherine R. Bevanda Trust Mr. Sergio Morescalchi 6731 Herndon Place Atlantic Richfield Company Stockton, California 95219 Post Office Box 1257 San Ramon, California 94583 Subject: ARCO Service Station No. 2186 LOP Case #: 001035 3212 North California Street Stockton, California 94570 The San Joaquin County Environmental Health Department (EHD) has received Well Destruction Work Plan (work plan), dated 07 February 2012, prepared by Stantec Consulting Services Inc. (Stantec) on your behalf. The EHD had directed the submittal of a well destruction work plan by letter dated 04 January 2012. In the work plan, Stantec proposes to destroy two wells (MW-1 R and MW-1 D) by removing the well components by over-drilling the wells. Further, noting that groundwater samples collected from wells MW-2, MW-3R, MW-4 through MW-8, VW-1B, VW-213 and VW-3B during the last groundwater monitoring event were either reported below the laboratory method reporting limit and/or maximum contaminant levels (MCLS) for contaminants of concern, Stantec proposes to destroy these wells by removing the top three feet of the well casings and pressure grouting the wells. Stantec also proposes to destroy former soil vapor extraction wells VW-1A, VW-2A, VW-3A, VW-4, and air sparge well AW-1, by pressure grouting, noting that the last vapor analysis from the influent location of the former soil vapor extraction system indicated contaminants of concern below the laboratory method reporting limit. The San Joaquin County Well Standards require over-drilling and removing well contents as the method of destruction if the well is in an area of known or suspected contamination. The EHD has reviewed the site data to determine if the wells proposed for destruction by pressure grouting qualify for that destruction method. The EHD determined that the following wells qualify for destruction by pressure grouting-, MW-2, MW-3R, MW-5. MW-6, MW-7, MW-8, VW-3A, VW-313, and VW-4- The remaining wells contained either impacted groundwater or impacted soil below the screen interval of the vapor extraction wells or in the saturated zone. Wells not qualified for pressure grouting include MW-1R, MW-1D, MW-4, VW-1A, VW-113, VW-2A, VW-2B and AW-1. These wells must be over-drilled. ,r-AVJ 3P,JA� Vapor wells VW-1A/VW-1B and VW-2ANW-2B are nested wells that were installed using ten- inch augers. The EHD has found destruction results of nested wells that are over-drilled are