I think the geographical ammendments would be a given.
I once did a school in central FL with a generic spec (engineer obviously was a snow bird)) calling for PVC to be buried something like 3'6" to accomplish a clearance of 10" below freeze level.
In central FL 10" below freeze level would be some where in a flight path.
This real situation on the flip would definatly have to come in to play in a true nationaly adopted code, which is where we are now isn't it?
Roger
