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and screwed together without the usa of cement. The slotted pipe will extend above the estimated seasonal high groundwater level. The annulus of the perforated section will be packed with clean No. 3 or 4 Monterey sand, or equivalent, for the length of the screen and approximately 2 feet above the uppermost slot. In order to create a spacer between the sand and annular seal, 2 feet of bentonite will be placed on top of the sand envelope pack. An annular seal of cement grout composed of portland-type I/II cement (94 pounds/5 gallons water) will be placed immediately above the bentonite layer to approximately 3 inches below surface grade. A sand/cement slurry also may be used with a minimum of 11 sacks of portland-type cement per cubic yard. If a sand/cement slurry is used it must be mixed off site at a batch plant. If more than 30 feet of seal is required, the sealant must be tremae-piped within 3 feet of the underlying material or bottom of the well. 6. An above-grade or at well completion will depend upon the final well location. An above-grade completion will require an 8- inch diameter steel, waterproof, locking, protective casing set into a concrete pad. A sketch of an above-grade completion is shown in Figure 2. An at-grade completion will require a steel casing and a Christy box, or equivalent, and a concrete pad with approximately 3 inches of slope away from the center of the well box. The purpose of this is to prevent surface runoff from entering the well box. A sketch of an at-grade completion is shown in Figure 3. A watertight cap will be installed on the well head and the top of the well will be secured with a locking cap and kept locked. 7. The cover of the well will be marked "Monitoring well". A small metal tag will be attached permanently to the well or within the well vault. This tag will include the well number, hole and casing diameters, location of screened intervals, and total depth of the well. 8. All borings will be sealed with a mixture of Portland-type I/II cement by txemie-piping to within at least 3 feet from the true bottom of the hole:. WELL DEVELOPMENT 1. All wells will be developed no earlier than 72 hours after seal emplacement and no later than 7 days after initial well installation. The wells will be purged and sampled at least 72 hours after well development. 2. Wells will be developed until water is free of fine-grained sediments -and/or until field measurements of Ph, conductivity and temperature stabilize. At least 5, and up to 10, well volumes of water will be removed during the development of the well. This water removal is accomplished by either bailing with a 1.5-inch diameter PVC bailer or using a bottom loading airlift pump. All Page 2 of fi 275 Gr_antline Rd. DSSP