Maximum oil content for discharge overboard is set at:

• A. 10 ppm
• B. 15 ppm
• C. 20 ppm
• D. 25 ppm

Answer: (B)

The main rule being tested is the regulatory limit on how much oil can be present in water discharged overboard after treatment. In ships, bilge water containing oil is treated by an oily water separator, and the discharge overboard must meet a maximum oil content of 15 parts per million. This limit is enforced by the ship’s oil content meter and related monitoring equipment, which ensure that only treated water with oil content at or below 15 ppm is released. If the meter reads above 15 ppm, discharge must be halted and the bilge water either further treated or stored for disposal at a reception facility. The 15 ppm standard balances practical operation with environmental protection, though some areas may have stricter local requirements.