What is the function of an oily-water separator (OWS), and what documentation must follow its operation?

What is the function of an oily-water separator (OWS), and what documentation must follow its operation?

• A. It reduces the oil content of bilge water before discharge; no records are required after use.
• B. It is used to separate fuel from the oil for reuse.
• C. It reduces the oil content of bilge water before discharge; after use, records must be entered in the Oil Record Book.
• D. It treats ballast water for discharge according to local regulations.

Answer: (C)

An oily-water separator is used to strip oil from bilge water so that any discharge overboard meets regulatory limits. Bilge water from engine rooms can carry oil, fuel, and other contaminants, and the separator uses gravity and filtration/coalescing to remove the oil. The cleaned water, with oil content kept below the permitted limit (typically 15 mg/L or 15 ppm under MARPOL), can be discharged while the ship is authorized to do so; the system is usually equipped with an oil-content monitor and will automatically stop discharge if the limit is exceeded or if the vessel is in a restricted area. After use, the operation must be recorded in the Oil Record Book, noting when and where the discharge occurred, the amount discharged, and that the discharge complied with the required oil-content limit. This logging provides regulatory traceability and proof of pollution-prevention compliance.

An oily-water separator is used to strip oil from bilge water so that any discharge overboard meets regulatory limits. Bilge water from engine rooms can carry oil, fuel, and other contaminants, and the separator uses gravity and filtration/coalescing to remove the oil. The cleaned water, with oil content kept below the permitted limit (typically 15 mg/L or 15 ppm under MARPOL), can be discharged while the ship is authorized to do so; the system is usually equipped with an oil-content monitor and will automatically stop discharge if the limit is exceeded or if the vessel is in a restricted area. After use, the operation must be recorded in the Oil Record Book, noting when and where the discharge occurred, the amount discharged, and that the discharge complied with the required oil-content limit. This logging provides regulatory traceability and proof of pollution-prevention compliance.