16 Del. Admin. Code § 4204-4.0
No interment of any human body shall be made in any public or private burial ground unless the distance from all parts of the top of the outer case containing the coffin or casket be not less than eighteen (18) inches (.5 meter) from the natural surface of the ground. EXCEPTION: Per Section 6, subsection c., of this regulation, bodies dead of designated high-risk diseases (Anthrax, Small Pox, Plague and the various Hemorrhagic Fevers) must be buried at a depth of at least 79 inches/ 2 meters.
The superintendent, sexton, caretaker, or other person in charge of a cemetery or burial ground shall be responsible that graves are of the depth required by this regulation. In the event that there be no such person in charge, it shall become the responsibility of the person burying the body.
16 Del. Admin. Code § 4204-4.0