Small diameter PVC wells are installed with a direct push rig using steel drive casing as shown in the figure. The drive casing size and corresponding PVC size are as follows:
DRIVE CASINGPVC SIZE
1.75” O.D. x 1.1” I.D. 3/4” 2.00” O.D. x 1.5” I.D. 1” 3.25” O.D. x 2.7” I.D. 2”
A disposable steel tip with an O-ring seal is placed in the end of the steel drive casing. The drive casing is then advanced to the bottom depth of the well. The PVC screen and blank are then installed inside the steel casing. The drive casing is pulled back, leaving the disposable tip and PVC well in the ground.
Sand and bentonite can be carefully poured around the annulus left by the drive casing. A small tape or sounder is used to check the depth of the sand and bentonite. A small diameter bailer or check valve sampler with 3/8 inch diameter tubing is generally used for groundwater sample collection. A well box can also be constructed at ground surface for a more permanent installation.
