[Superman]

Your guesses are spot on. Thanks muchly for the advice. Perhaps I will draw up a grid map to consider.

One thing I am not clear on, and perhaps several here could answer, is how to install the underground "T." When I have installed pipe systems, I have started at one end and ended at the other. But if I cut a slice out of an underground pipe, how do I get the two female collars, and the T fixture, on? I cannot move the existing pipe to create sufficient room and then move it back into place.

And wouldn't polyethylene pipe be better? Somewhat bendable, when warm enough. That is what I used to replace a failed incoming water line to a house I owned years ago.