trench plug

[anbm]

will conduit run under the building or underground require trench plug? I have seen some civil drawing details indicates trench plug is needed for all undergrounbd utility pipes run.

 

[cadpoint]

I'm almost sure it's part of your State's Building Code. Your mileage might vary.
Here are 22 Pages of NC Section 450 with no Back reference to its origin other than its link.