Borehole construction methods, and the drillers
that employ different borehole construction
methods, are classified in a few different ways.
1. By the borehole creation method- jetting, cable
tool, auger, sonic, rotary.
2. By the fluid used to remove the debris of
drilling. More about drilling fluids in a moment.
3. By the casing installation method- driving
casing or drilling an oversized hole and
grouting it in place. Plastic casing cannot be
driven into the ground because of strength
issues. This fact gives rise to a whole other
approach to borehole construction.
Whichever construction method is chosen, the
integrity of the casing and the sanitary sealing of
the casing to prevent surface and shallow
subsurface contamination is critical.
Always remember the entire concept of drilling is
based on the layers of the earth and humankinds
ability to create a passageway for water through
these layers that draws only from the deeper layers
while completely insulating the passageway from
the surface to the water bearing layer.