In accordance with the international MARPOL Annex VI regulations, what is a permissible alternative to burning oil residue sludge in an appropriate incinerator?

Correct Answer: Option A — The oil sludge residue may be burned in a boiler OR engine, and it AND may be burned only in unrestricted waters (other than in port, in harbors, or estuaries).

MARPOL Annex I, Regulation 16, permits the burning of oil residue (sludge) in main or auxiliary boilers or engines. However, this practice is strictly prohibited within port, harbor, or estuary waters. It must be conducted in unrestricted waters to ensure compliance with international discharge and emission control requirements.