Ridged conduit

Is buried ridgid 6" to top of pipe or 1ft in non traffic(ie no vehicals,or under
driveways ect.) what would NEC book say.

I assume you mean rigid metal conduit and not pvc.

In open areas: 6" cover
One and two family driveways & parking areas: 18" cover
Under streets, highways, roads, alleys, driveways, and parking lots: 24" cover
Airport runways: 18" cover

Thanks speedy for the confirmation.And yes ridgid metal conduit.