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16 December 2021 AdvancedGeo Project No. 07-1529 An Employee-Owned Company Page 2 of 3 � stem augers will be utilized as a tremie pipe during deployment of the grout mixture. Any groundwater displaced by the grout mixture will be routed into properly labeled Department of Transportation (DOT)-approved 55-gallon drums. All investigation derived waste will be containerized in properly labeled DOT-approved 55-gallon drums and disposed as a non-hazardous waste. AGI proposes to destroy well EW-1 using wire-line explosives. Prior to destruction, the well integrity will be checked using a water level meter. Initially, a cord of 50-grain Special wire-line explosives will be deployed down the entire length of the well casing to a total depth of 120 feet bsg. Once the explosives are in place the entire casing will be filled with the grout mixture as described above. Once filled, the charges will be detonated and EHD and AGI staff will verify that the grout mixture has dispersed into the surrounding formation. The remaining space, following formation shrinkage, will be filled with the grout mixture to near surface grade. 3.0. REPORTING Upon completion of field work and disposal of waste, a well destruction report describing the activities and procedures, including documentation of waste disposal, will be prepared, and submitted to the EHD and Regional Water Quality Control Board (RWQCB). The report will be in a format acceptable to the EHD and the RWQCB and will be reviewed and signed by a California Professional Geologist. 4.0. MRP RESCISSION Based on the results of corrective action injections performed historically at the site, AGI requests that the Waste Discharge Requirement (WDR) permit and associated Amended MRP be rescinded. Petroleum hydrocarbon-impacted soil and groundwater have been treated at the site utilizing a combination of soil-vapor extraction (SVE) and in-situ chemical oxidation (ISCO) injections. An SVE system operated at the site from June 1994 to December 1996 and removed a total of 16,200 pounds of hydrocarbon impact during that time. ISCO pilot tests and corrective action have been performed in the "core" area of the plume near wells MW-9, MW-13, and EW-1 from 2011 to 2018. A detailed history of SVE remedial operations performed at the site was included in the AGI-prepared, Corrective Action Plan, dated 10 June 2014. It is AGI's opinion that the reduction in dissolved mass observed is not sufficient to justify the costs to perform injections and the monitoring and sampling required by the Amended MRP. The corrective action injections are not economically feasible relative to the results. Therefore, AGI requests the WDR permit and Amended MRP be rescinded.