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NOTE: Abandonment sealant consisted of 50 pound bags of "Bore-Gel" bentonite, <br />mixed with approximately 1 gallon of water per pound in a 200 gallon stock tank. Once <br />the hole was drilled to total depth, it was blown clean of cuttings and the mixed sealant <br />pumped through the drill string, until the sealant circulated to the top of the hole. The <br />drill pipe was then "tripped" out of the hole and additional sealant pumped into the hole, <br />as the drill pipe was withdrawn. In all cases, the sealant level would drop to the top of <br />the unweathered bedrock, typically at a depth between 10 and 20 feet. The drill rig <br />would then move off the hole and onto another location. Each of the holes was logged <br />with geophysical tools. After logging, the drilling contractor would complete final <br />reclamation of each hole by dumping 2 50 pound bags of bentonite chips into the hole, <br />then shoveling cuttings into the hole to a depth of 10 feet below the surface. The final ten <br />feet of hole was then filled with concrete. An aluminum survey monument labeling each <br />hole was set in the concrete at the surface. See attached figure for diagram (Figure 1). <br />Any remaining cuttings were removed or dispersed and the area seeded with the <br />approved seed mixture. <br />The location of hole CB07-20 and the twinned core hole CB07-20C was located in a hay <br />meadow that is planned to be converted into plowed farmland in the next two years. The <br />two holes at this location were reclaimed in the same manner as all other except that the <br />concrete plug extends from ten feet from the surface to three feet from the surface. The <br />top three feet of the hole was filled with native soil. These holes were also not marked <br />with a survey cap. <br />7 <br />