Question 740Steam Plants - Assistant Engineer

The correct answer is B) oil contamination. The contaminated drain system on a vessel is designed to collect and route drains that may be exposed to oil contamination, such as bilge water, engine room drains, and other areas where oil may be present. This is to prevent the oil-contaminated water from being discharged directly overboard, which would violate environmental regulations. The other answer choices are incorrect because they do not accurately reflect the typical purpose of a contaminated drain system. Salt water, boiler treatment chemicals, and spoiled food would not be the primary contaminants that this system is designed to handle.