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• DDJacy OU 1 Pesticide Remediation Groundwater Piezometer Abandonment and Installation Work Plan prior to installation.The well screen will have and then tremied in place.No accelerator will be smooth, sharp-edged openings free of burrs, added to the grout. Guidelines for the installa- chipped edges,of broken pieces on the interior tion of the grout seal are presented in the DD✓C- and exterior surfaces of the pipe. Sections of the Sharpe/Tracy Comprehensive Field Work Plan screen will be received from the supplier Field Procedures(URS,2004c). wrapped in polyethylene protective wrappers with sealed ends to limit exposure to potential 4.6 Wellheads contaminants.Wrapping will not be removed until the screen is to be used. Once the grout seal has been tremied into place and time has elapsed to allow for the grout to 4.3 Filter Pack cure,a locking steel casing will be installed around the piezometer casing and set into a The filter pack material will be composed of concrete pad.Bollards consisting of concrete- round,hard,water-wom siliceous sand and be filled,4-inch-diameter steel pipe will be cast free of flat or elongated pieces,organic matter, into the concrete slab.Details describing the or other foreign matter. All filter pack material surface completion are presented in the DDJC- will be protected from contamination prior to Sharpe/Tracy Comprehensive Field Work Plan placement by either storing it in plastic-lined Field Procedures(URS, 2004c). paper bags or on plastic sheeting in a location protected from the weather and contamination. 5.0 POST-PIEZOMETER- All filter pack material will be placed in the INSTALLATION ACTIVITIES annular space in the borehole by using a 2-inch tremie pipe.A complete description of the 5.1 Investigation-Derived Waste guidelines to be used for the installation of filter pack material is presented in the DDJC- Investigation-derived waste(IDW)will be Sharpe/Tracy Comprehensive Field Work Plan managed in accordance with the procedures Field Procedures(URS, 2004c). described in the DDJC-Sharpe/Tracy Compre- hensive Field Work Plan Field Procedures 4.4 Bentonite Seal (URS,2004c)and the DDJC-Sharpe/Tracy The piezometers will be constructed with a Waste Management Plan(URS,2004d). bentonite seal placed above the filter pack to 5.2 Piezometer Location Surveying protect the filter pack during grouting.The bentonite seal will consist of bentonite pellets or Horizontal coordinates will be determined to the chips. Once the seal is in place,the interval will closest 1.0 foot and referenced to the State Plane be hydrated for a minimum of 30 minutes, Coordinate System,Zone 3,North American before grouting occurs. Guidelines for the Datum of 1983. Ground surface and top-of- installation of the bentonite seal are presented in casing elevations will be obtained at the the DDJC-Sharpe/Tracy Comprehensive Field piezometers to the closest 0.1 foot and 0.01 foot, Work Plan Field Procedures(URS,2004c). respectively.These elevations will be referenced to the National Geodetic Vertical Datum of 4.5 Cement Grout 1988. A cement grout will be used to fill the annular 5.3 Groundwater Water Level space above the hydrated bentonite seal.Cement Measurements grout will consist of Type II Portland cement with 3 pounds of powdered non-beneficiated Water level measurements will be collected bentonite and 7 gallons of water per 94-pound from the piezometers quarterly as part of the sack of cement. The cement grout will be annual monitoring program.Data collection will mechanically mixed with a paddle-type mixer be performed in accordance with procedures KAWpr ess\00701\Tmcy\0U1 Pst PL AWORAFINtext m 5 June 2004