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FINAL • DDRN*arpe Well Installation W rk Plan • Reference elevation for all depth support the filter pack and in-situ soils measurements; surrounding the screen. The well screen rface will be free of solvents, oils, grease, pain , and • Boring abandonment procedures (if dirt and will be certified clean from the f Lctory applicable); or steam-cleaned on site prior to installa on. • Name of driller; and The well screen will have smooth, sharp- dged openings free of burrs, chipped edges, or broken • Name and signature of the field geologist pieces on the interior and exterior surfaces of preparing the log. the pipe. Sections of the screen will arriv certified as clean by the supplier, and wrapped 4.0 MONITORING WELIJ in polyethylene protective wrappers with sealed PIEZOMETER CONSTRUCTION ends in order to limit exposure to potenti contaminants.Wrapping will not be removed Installation of five groundwater monitoring well until screen is to be used. clusters and one piezometer cluster are recommended for this field effort. Proposed 4.3 Filter Pack monitoring well and piezometer locations are shown in Figure 2-1.Figure 4-1 shows The filter pack material will be composei I of generalized specifications for piezometer and round,hard, waterworn siliceous sand, fr 5e of monitoring well wellhead completion. flat or elongated pieces,organic matter,or other foreign matter. All filter pack material w 11 be 4.1 Well Casing protected from contamination prior to pl cement by either storing it in plastic-lined paper ags or Well casing will be 2-inch and 4-inch nominal in a location protected from the weather ind diameter Schedule 40 PVC pipe with flush contamination on plastic sheeting. threads for the piezometers and monitoring wells, respectively.The casing surface will be 4.4 Bentonite Seal free of solvents, oils,grease,paint, and dirt and will be certified clean from the factory. In A bentonite seal will be placed above the filter addition, the casing will be steam-cleaned on pack to protect the filter pack during gro ting. site prior to installation. Sections of casing will The bentonite seal will be made from bentonite arrive certified as clean by the supplier, and pellets or chips. wrapped in polyethylene protective wrappers with sealed ends in order to limit exposure to 4.5 Cement Grout potential contaminants.Casing will not be removed from the wrapping until immediately A cement grout will be used to fill the annular before it is to be placed in the boring. space above the filter pack. Cement groi t will consist of Type II Portland cement with 4.2 Well Screen pounds of powdered nonbeneficiated be itonite and 7 gallons of water per 94-pound sac of The well screen will be 2-inch and 4-inch cement.The cement grout will be mech nically nominal diameter,Schedule 40 PVC slot screen mixed with a paddle type mixer.No acc Aerator with flush threads for the piezometers and will be added to the grout. monitoring wells, respectively.All screen openings will widen inward so as to be non- 4.6 Wellheads clogging.The slot size will be compatible with the filter pack that will surround the screen;slot Wellheads will be constructed as shown and size and filter pack will be determined based on with those materials indicated in the wellhead pilot boring lithologies. The well screen will be construction details on Figure 4-1. The of sufficient size and design to hold back and ` S-SSWP.DOC 6 Sep tuber 1996