What is required on a ship for Annex IV?

• A. A sewage treatment plant
• B. A sewage comminuting and disinfection system
• C. A sewage holding tank
• D. Any of the above, provided the system is type approved

Answer: (D)

Annex IV focuses on preventing pollution from sewage by requiring ships to be equipped with a system on board that is type-approved for handling sewage. The crucial point is that the system itself must carry type approval from the ship’s administration or a recognized organization, confirming it meets the required standards for treatment or containment. Because several technologies can meet these standards, any of the three options can be acceptable once they are type-approved: a sewage treatment plant that treats sewage before discharge, a sewage comminuting and disinfection system that macerates and disinfects sewage before discharge, or a sewage holding tank that stores sewage to be discharged at a port reception facility. The common thread is the type-approved status; without it, discharging sewage at sea is not allowed.