Sounds like you're good to go. I used pvc, but here we have to go 24" down. If I had to do it again, I would probably go with ridgid, which costs more but requires so much less digging.
I'm using pvc, which is stiff, not flexible. Is this not the same as rigid? What exactly is rigid? I like the idea of rigid for a few more bucks and a lot less digging. My run is only about 8', so cost difference will be minimal.