Trenching & Piping

The supply line is on the right, with the T connection to the East hole

Both returns run from the far hole to balance the flow.

(This posting was delayed; I'll explain in my next post).  The drilling contractor finished the outside work. This final step was referred to "trenching". An medium size excavator and dump truck visited. The trench they dug was impressive. Much bigger than I imagined.  They hit so many rocks that they have to come back to remove more boulders and dirt.


They used a hot-plate like device to heat the HDPE pipes to 500 degrees to join them together.

They used a torch to cut the pipe casings 4 feet below grade. But before they cut the casings, they inserted another metal pipe in to the casing to protect the HDPE tubes.


They ran both the returns from the farther hole to balance the flow between the holes. They also used different pipe diameters to balance the flow.

They put a rubber gasket around the top of the pipe casing to protect the HDPE pipes.

The picture on the right shows how they used a great big cork-screw drill to bore the 2 holes in the side of the foundation.

Once everything was connected, they flushed the tubes and performed a pressure test. Using water from my irrigation system, they filled the pipes, drained the air and pressurized the pipes to 90 PSI (lower right). It was a little unnerving to watch it steadily dropping  to 72 PSI. They said that was expected because of the expansion of the tubes.

Surprise discovery #1:  I have the rockiest lawn they've ever encountered. They dug up so many boulders they filled their dump truck and have to visit again to collect a few more.

Surprise discovery #2: a second unexpected pipe for the lawn irrigation system. This one with electricity attached. The irrigation company will visit on Monday to reconnect those wires. The trenching team reconnected the two pipes that they cut.