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I <br /> OVATC <br /> A S S O C I A T E S I N C . <br /> For protection of the seal at the land surface, a hole at least one foot larger than the diameter of <br /> the original borehole will be excavated around the outside of each well casing to a depth of <br /> approximately three feet below ground surface. The sealing material used to seal the well will be <br /> allowed to spill over into the excavation. <br /> Monitoring well MW4 will be destroyed by overdrilling the casing and sandpack to a depth of <br /> approximately 30 feet. The boring will be backfilled with a neat cement/bentonite grout mix to <br /> within approximately two feet of the ground surface: <br /> After the sealing material has set in wells MWl through MW7, the excavations will be filled to <br /> within approximately 3 inches of surface grade with an aggregate material and the remaining 3 <br /> inches will be filled with asphalt patch to restore the site's appearance. <br /> Based upon well construction details and assuming the filter pack for each well has an estimated <br /> porosity of 25% (Heath, R. C., 1983), an estimated volume of approximately 169 gallons of grout <br /> will be used to abandon wells MWl through MW7. Monitoring well construction data, soil <br /> boring logs, and grout volume calculations are attached. <br /> Report Preparation <br /> Upon completion of the well destruction activities, a summary report will be prepared for <br /> submittal to San Joaquin County Environmental Health Department (SJCEHD). The report will <br /> include a description of all field activities. <br /> All work described in this workplan will be performed under the direction of a California <br /> Registered Professional Engineer. All work will be performed in accordance with ATC's Site <br /> Safety Plan and Quality Control/Quality Assurance Plan for this site, on file at SJCEHD. <br /> Proiected Schedule <br /> Once approval of this workplan has been received, ATC will schedule drilling activities. ATC will <br /> notify SJCEHD prior to beginning any field activities. The summary report will be submitted to <br /> SJCEHD approximately four to five weeks after the completion of field activities. <br /> WAI30994p-wellabandonmentdoc 2 <br />