Referring to the illustration, note that the solenoid in line "C" is closed. The check valve in line "E" is open. The separator service pump is running. The check valve in line "G" is closed. Valve "B" is closed. Valve "D" is open. What is the operational status of the oily-water separator unit? Illustration GS-0175

Correct Answer: Option A — The oily-water separator is in the bilge water separation processing mode with water discharging back to the bilge water holding tank with an oil content greater than 15 ppm.

When valve B is closed and D is open, the processed water is diverted back to the bilge holding tank. This configuration is used when the oil content exceeds the 15 ppm limit, preventing illegal overboard discharge and ensuring compliance with international pollution prevention regulations for oily water separators.