Which statement correctly pairs bilge water oil content with its unit and incinerator ash status?

• A. The maximum bilge oil content is 15 ppm, and incinerator ash discharge is never permitted.
• B. The maximum bilge oil content is 5 ppm, and incinerator ash discharge is never permitted.
• C. The maximum bilge oil content is 15 ppm, and incinerator ash discharge is always permitted.
• D. The maximum bilge oil content is 50 ppm, and incinerator ash discharge is never permitted.

Answer: (A)

This item tests regulatory limits on bilge water oil content and how incinerator ash is handled at sea. Bilge water that collects in a ship’s bilge is treated through an oily-water separator, and the oil content of the water discharged overboard must be kept to a very low level—specifically 15 parts per million. This unit, ppm, measures how much oil is present per million parts of water, and staying at or below 15 ppm minimizes environmental impact. On the other hand, ash from onboard incinerators is a solid waste residue, and discharging incinerator ash at sea is not allowed. It must be retained on board or disposed of ashore in compliance with regulations. So the best pairing is 15 ppm for bilge oil content and a rule that incinerator ash discharge is never permitted. The other options either give an incorrect concentration limit or imply that incinerator ash can be discharged, which is not permitted.