Laserfiche WebLink
04 May 2022 AdvancedGeo <br /> Project No. 02-0926 An Employee-Owned Compony <br /> Page 2 of 2 <br /> Prior to well destruction activities, all wells will be checked for total depth and well integrity <br /> using a Solinst water level meter. Any obstructions found in the wells will be removed. <br /> AGI proposes to destroy wells MW-4 and MW-9 by over drilling. The wells will be <br /> drilled-out to total depths of 40 feet bsg utilizing a hollow-stem auger drill rig equipped <br /> with 8-inch diameter augers. All original well construction materials will be removed <br /> (including well casing, screen, filter pack, and annular seal) by the drill rig to ensure that <br /> no residual contamination is sealed within the abandoned borehole and a vertical conduit <br /> does not remain. The boring will be completely backfilled to surface grade with a cement <br /> grout mixture (Portland type II) and finished at the surface with native soil or concrete to <br /> match the existing surface. The grout mixture will consist of a ratio of not more than six <br /> gallons of water for every 94-pound sack of Portland type II cement. The drill rig hollow <br /> stem augers will be utilized as a tremie pipe during deployment of the grout mixture. Any <br /> groundwater displaced by the grout mixture will be routed into properly labeled <br /> Department of Transportation (DOT)-approved 55-gallon drums. All investigation derived <br /> waste will be containerized in properly labeled DOT-approved 55-gallon drums and <br /> disposed as a non-hazardous waste. <br /> 3.0. REPORTING <br /> Upon completion of field work and disposal of waste, a soil sampling and well destruction <br /> report describing the activities and procedures, including documentation of waste <br /> disposal, will be prepared, and submitted to the SJCEHD. The report will be in a format <br /> acceptable to the SJEHD and will be reviewed and signed by a California Professional <br /> Geologist. <br /> Sincerely, <br /> AdvancedGeo, Inc. <br /> Evan J. Schmidt Daniel J. Villanueva <br /> Staff Geologist Senior Geologist <br />