If an ISPPC doesn't comply with MARPOL IV, what must it comply with?

• A. 33 CFR 159 (Marine Sanitation Devices)
• B. MARPOL IV/5.1
• C. NVIC 01-09
• D. MEPC.1/CIRC.736/REV.2

Answer: (A)

If a ship cannot meet MARPOL Annex IV, the regulation that takes precedence as the backup standard in U.S. waters is the Marine Sanitation Device rule in 33 CFR 159. This regulation sets the requirements for the design, certification, and use of onboard marine sanitation devices, and it strictly limits or prohibits the discharge of sewage into U.S. waters unless the discharge comes from an approved MSD and complies with the device’s performance standards. In other words, while MARPOL governs international pollution prevention, 33 CFR 159 provides the domestic mechanism to ensure sewage is properly treated or contained when MARPOL compliance isn’t being met, so ships operating in U.S. ports or waters must adhere to those rules.

The other options are not substitutes for MARPOL in this context. MARPOL IV/5.1 is part of the same international convention, not an alternate standard. NVIC 01-09 is guidance issued by the Coast Guard and does not establish the mandatory compliance framework in place of MARPOL. MEPC.1/CIRC.736/REV.2 is a circular that clarifies MARPOL interpretations, not a standalone fallback regulation.