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be put in place by pouring the pellets slowly into the well annulus from the surface. The volume of pellets required to form the seal will be calculated prior to constructing the seal. The actual seal thickness will be determined by probing with a weighted sounding device during the sealing procedure. Precautions will be taken to insure that the bentonite seal is free of voids and that the bentonite pellets do not bridge above the specified seal interval. Alternatively, a five (5) foot thick, heavy bentonite slurry seal may be tremmied in place above the transition zone. Precautions will be taken to insure that the tremmied seal is present at its proposed upper depth prior to initiation of the grout seal placement. 2.3.11 Grout Seal Following the placement of the bentonite seal, the annulus must be grouted from the top of the bentonite seal to the ground surface. Grout will consist of a 20:1 mixture of Portland I neat cement to bentonite powder and must be thoroughly mixed before placement in the borehole. A maximum of eight gallons of water per 94-pound bag of cement will be used. The grout mixture can be produced on-site by the contractor or trucked in from an outside source. The grout must be pumped using tremmie techniques to displace drilling fluids from the drill casing, withdrawing the casing as the grout level rises. It is left to the discretion of the supervising geologist to determine if tremmie methods through the drill casing are required for the entire well for proper completion. 2.3.12 Development by Swabbing Following a minimum 24-hour waiting period to allow for grout setup, the wells will be developed by bailing, swabbing and airlifting techniques. Well development shall be initiated by bailing with a suitable sized bailer to remove any formational or filter pack materials from the bottom of the well bore. Swabbing will 13