Yikes. I wouldn't plant anything water-hungry anywhere near any sort of water-based piping, whether it be sprinkler, septic, plumbing, etc.
If I were you, which I'm personally doing anyway, I'd keep it in a bigger pot if there were no other in-ground choices. I've got a Cali-Gold from Tony as well, and mine's in a very, very big pot.
Happy fella so far.