Guard posts shall comply with all of the following requirements:
- Constructed of steel not less than 4 inches (102 mm) in diameter and concrete filled.
- Spaced not more than 4 feet (1219 mm) between posts on center.
- Set not less than 3 feet (914 mm) deep in a concrete footing of not less than a 15-inch (381 mm) diameter.
- Set with the top of the posts not less than 3 feet (914 mm) above ground.
- Located not less than 3 feet (914 mm) from the protected object.