I think they made the depth one foot now.
I had buried to the old spec of two feet years ago.
(I was running Class 1 wiring though. -- 120v-AC, don't mix that in same pipe.)
I always used plastic pipe/conduit.
Rick Glazier
From: "maccrawj"
Conduit STRONGLY recommended between cave & house. Make sure to follow correct
procedures/codes about depth of the run and the height at each termination end. LV
only, no power lines in same conduit!
Even if there is direct burial cable, go the conduit route it gives more
options later.