When the oily water separator, shown in the illustration, is in operation and processing clear bilge water, what should be the internal water level? GS-0153

Correct Answer: Option C — The water level should be located in the upper section of the tank.

Oily-water separators operate on the principle of gravity separation, requiring the tank to be completely filled with liquid. The internal water level must be maintained in the upper section to ensure that the coalescer beds are fully submerged, allowing for effective oil droplet capture and separation.