Locations and access had been scouted during a prior trip.
The drilling crew completed about two holes holes per day.
While, air drilling in limestone can be a dusty operation, it causes far less impact on the surrounding countryside than a more conventional vault excavation. The holes were drilled oversized such that there would be sufficient clearage to cement the casing from the surface down.
Once the hole is drilled and before the casing is set,
several feet of a cement grout is poured into
the bottom of the hole. This will form the 'floor' of the
The casing is then carefully lowered into this slurry, plumbed, and then left while the slurry sets (usually overnight).
On the next day, the cemeting is completed
by pouring a slurry around the outside of the
casing until the entire length is cemented.
The top of the casing is capped to seal out
rain water and rocks from interested children.