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26 July 2022 dvanc Employee- Company Project No. 22-6943 Page 2 of 3 Institute for Occupational Safety and Health Administration, U.S. Coast Guard and U.S. Environmental Protection Agency, 1985). Prior to drilling activities, each proposed drilling location will be clearly marked, and utility clearance obtained through Underground Service Alert. Well abandonment/destruction permits will be obtained from the San Joaquin County Environmental Health Department (EHD); additionally, the EHD will be notified a minimum of 48-hours prior to commencement of well destruction activities. Prior to well destruction activities, all wells will be checked for total depth and well integrity using a Solinst water level meter. Any obstructions found in the wells will be removed. AGI proposes to destroy three groundwater monitoring wells (MW-1, MW-2 and MW-3) by pressure grouting. Pressure grouting will include the removal of the well box and cap to expose the well casing. Each well will initially be filled over its entire depth with a thick grout mixture (no less than 6 gallons of water per 94 bag of cement). Any groundwater displaced by the grout mixture will be routed into properly labeled Department of Transportation (DOT)-approved 55-gallon drums. Once the well is filled with the grout, the well head will be fitted with a pressure tight adapter and air pressure will be added at approximately 10 pounds per square inch (psi) of pressure for a minimum of 10 minutes. The added pressure will be used to force a significant portion of the grout mixture out through the screen, sealing the well. Additional grout will be added to the casing as required. The top of each pressure grouted well will then be over-excavated to a depth of approximately three feet below surface grade (bsg) using a 20-inch diameter auger (steel cookie cutter). The well casing will be removed at a depth of 2.5 feet bsg, and grout will be used to the fill the excavation to a depth of 2 feet bsg ("mushroom cap"). The remaining borehole will be finished at the surface with concrete and/or native soil to match the existing surface. All investigation derived waste will be containerized in properly labeled DOT-approved 55-gallon drums and disposed as a non-hazardous waste. REPORTING Upon completion of field work and disposal of investigation derived waste, a well destruction report describing well destruction activities and procedures, including documentation of waste disposal from well destruction and other activities will be prepared and submitted to the EHD. The report will be in a format acceptable to the EHD and will be reviewed and signed by a California Professional Geologist.