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• DDJC-Sharpe Groundwater Ritoring Well Installation Work Plan foreign matter. All filter pack material will be 4.6 Wellheads protected from contamination prior to placement by either storing it in plastic-lined paper bags or Once each well's grout seal has been tremied in a location protected from the weather and into place and time has elapsed to allow for the contamination on plastic sheeting.All filter grout to cure,an 8-inch-diameter locking steel pack will be placed in the annular space in the casing will be installed around the well casing borehole by using a 2-inch tremie pipe. Once the and set into a concrete pad.Bollards consisting filter pack is in place,the driller will develop of concrete-filled,4-inch-diameter steel pipe the interval until no measurable decline in the will be cast into the concrete slab. Guidelines filter pack is measured. All water placed into the for the surface completions are presented in the borehole during the construction process will be DDJC-Shalpe/Tracy Comprehensive Field accounted for and removed before the well is Work Plan Field Procedures(URS,2004a). developed. A complete description of the guide- lines that are to be used for the installation of 4.7 Investigation-Derived Waste filter pack material is presented in the DDJC- Sharpe/Tracy Comprehensive Field Work Plan Investigation-derived waste(IDW)will be Field Procedures(URS,2004a). managed in accordance with the procedures described in the DDJC-Sharpe/Tracy Waste 4.4 Bentonite Seal Management Plan (URS,2004b). Each monitoring well will be constructed with a 5.0 POST-WELL INSTALLATION bentonite seal placed above the filter pack to ACTIVITIES protect the filter pack during grouting.The bentonite seal will consist of bentonite pellets or 5.1 Monitorinq Well Development chips. Once the seal is in place, the interval will be hydrated for a minimum of 30 minutes before Each well will be developed after well casing grouting occurs. Guidelines that are to be used installation. Well development procedures will for the installation of the bentonite seal are follow those outlined in the DDJC-Sharpe/ presented in the DDJC-Shalpe/Tracy Compre- Tracy Comprehensive Field Work Plan Field hensive Field Work Plan Field Procedures Procedures (URS,2004a).Wells will be bailed (URS,2004a). with a sand-pump bailer to remove fine sand inside the well casing; bailing will continue 4.5 Cement Grout until fine-grained sediment removed from the well decreases to less than an estimated volume A cement grout will be used to fill the annular of 1 ounce of sediment in one bailer load.The space above the hydrated bentonite seal. Cement well will then be surged for at least 30 minutes grout will consist of Type lI Portland cement or until the amount of sediment entering the with 3 pounds of powdered nonbeneficiated well decreases to a level deemed acceptable to bentonite and 7 gallons of water per 94-pound the field geologist.Well development data sack of cement.The cement grout will be recorded will include field determinations of mechanically mixed with a paddle-type mixer pH,temperature, specific conductivity,turbidity and then tremied in place.No accelerator will be data,the total number of well volumes purged added to the grout. Guidelines that are to be from the well during development, and the used for the installation of the grout seal are average pumping rate during development. presented in the DDJC-Sharpe/Tracy Compre- hensive Field Work Plan Field Procedures 5.2 Well Location Surveying (URS,2004a). The top of casing elevation will be measured for each of the newly installed monitoring wells. Horizontal coordinates will be determined to the KAWpr0cess\00363\tharpe\MW lnstanationWINAUMW526.doc 6 June 2004