I have come across more metal ridgid pipe underground (even wrapped with 20ml tape) that was rusted out. I've come to the conclusion that PVC is the way to go. Schedule 80 is so thick, it is probably almost as strong as metal ridgid. It should be legal to use at a 6" depth like metal ridgid, think PVC is 18" now.
The schedule 80 PVC also says ridgid on it, is it legal at 6"?
Any thoughts?

The Golden Rule - "The man with the gold makes the rule"