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WORK PLAN FOR DESTRUCTION OF <br /> MONITORING AND REMEDIATION WELLS <br /> Larry's Auto <br /> 308 N. Grant Street <br /> Stockton,CA 95202 <br /> 1.0 INTRODUCTION <br /> This Work Plan for Destruction of Monitoring and Remediation Wells (Work Plan)has been prepared by <br /> Condor Earth(Condor)at the request of the Central Valley Regional Water Quality Control Board(Central <br /> Valley Water Board). Presented in this Work Plan is the proposed scope of work to destroy vapor probes, <br /> monitoring, extraction, and air sparging wells that were used to remediate soil and groundwater at the <br /> property located at 308 N Grant Street(Assessor Parcel Number[APN] 139-320-130),which is associated <br /> with multiple addresses including 308 N Grant Street and 825 E Miner Avenue, in Stockton, California <br /> (Site,Figures 1 and 2,Appendix A).In a letter dated December 30,2024,the Central Valley Water Board <br /> confirmed the Site met all of the closure criteria established in the Low Threat Underground Storage Tank <br /> Case Closure Policy(LTCP)and concurred with the recommendation to close the case. Subsequently, in a <br /> letter dated April 8, 2025 Central Valley Water Board staff directed the destruction of all remaining Site <br /> monitoring and remediation wells,decommissioning and removing any remaining remediation equipment, <br /> and removing any associated Site waste. <br /> Included in this Work Plan are Figures 1 through 3 (Appendix A), well construction logs (Appendix B), <br /> Site-Specific Health and Safety Plan (HASP, Appendix C), Well Blasting documentation (Appendix D), <br /> and the Central Valley Water Board's Request for Well Destruction Letter dated April 8, 2025 (Appendix <br /> E). <br /> 2.0 PROJECT BACKGROUND <br /> The Site historically housed multiple underground storage tanks(USTs)associated with fuel and waste oil <br /> storage. Between 1987 and 1990, the USTs were removed and the soils beneath the tanks were identified <br /> as impacted by petroleum hydrocarbons and trichloroethane (TCE). Subsequent site investigations <br /> conducted included soil, groundwater, soil vapor investigations, free product recovery and cone <br /> penetrometer testing (CPT). These investigations involved the installation multiple monitoring and <br /> remediation wells including nine (9) groundwater monitoring wells (MW-1 through MW-9), two (2) <br /> extraction wells (EW-1 and EW-2), eight (8) vapor wells (VW-2 through VW-9), including two multi- <br /> completion vapor wells(VW-2A,B and VW-5A,B,C)four(4)air sparge wells(IAS-1 through IAS-4)and <br /> five (5) shallow soil vapor probes (VP-1 through VP-5). Following completion of remedial actions and <br /> evaluations of the Site conditions,the Site was determined to meet the LTCP closure criteria. <br /> 3.0 SUBSURFACE CONDITIONS <br /> Based on previous investigations, the soil beneath the Site consists of interbedded silts, clays, and sands <br /> between approximately 5 feet below ground surface (bgs) to approximately 155 feet bgs, the maximum <br /> depth explored. The depth of groundwater was measured between approximately 32 to 38 feet bgs. <br /> 4.0 SCOPE OF WORK <br /> Condor will oversee the destruction of a total of twenty-eight (28) monitoring and remediation wells, as <br /> described in Section 2.0 above. The locations of Site wells are shown in Figure 3 (Appendix A). Well <br /> destructions will be completed pursuant to the San Joaquin County Well Standards and California Well <br /> 40 <br /> to co S6 <br />