There's a lot of excitement in the Environmental Industry about Geoprobe® Prepacked Well Screens designed for setting Monitoring Wells. Prepacked screens consist of a standard, slotted PVC well screen pipe surrounded by a stainless steel mesh. Sand is packed between the slotted PVC and the stainless steel mesh. Since the sand is packed around the slotted PVC before the well screen is installed, using prepacks guarantees that sand will be located directly around the well screen. This makes well installation quicker and more efficient than traditional methods.
Prepack well screens are available in 0.5 in., 0.75 in.,1.0 in. or 1.5 in., 2.0 in. ID. To install a monitoring well with prepacks, probe rods are first driven to depth with a Geoprobe® machine. The well assembly is then lowered into the probe rod string with threaded PVC riser pipe.
Once the well assembly is lowered to the bottom of the probe rod string, the probe rods are retracted to a point above the screen. A sand barrier, installed directly above the well screen, prevents grout from entering the screens. With the barrier in place, granular bentonite or bentonite slurry is then installed in the annulus to form a well seal.