The Navy's shipboard oily waste problem is defined. The nature, sources, and generation rates of oily waste produced by Naval ships while in port and at sea under various modes of operation are presented.
In surveys of bilge oily waste conducted on 32 ships, bilge fluid generation rates, while in-port cold iron, ranged from a low of approximately 3,000 gallons per day for various destroyers to a high of 80,000 gallons per day for an attack carrier. These fluids were characterized as approximately 99.9% water; oil films or layers amounted to 0.1% of the total bilge fluid volume. The water layer contained less than 91 parts per million oil and 34 milligrams per liter solids 90% of the time. The principal particulate constituents are defined as approximately 75% organic and 25% inorganic with the major inorganic elements comprised of iron oxide, zinc and aluminum.
Questionnaire surveys of nearly 500 ships, followed by some ship visits, indicate that approximately 10% of all shipboard oily waste is comprised of ballast waters of which 73% is contributed by oilers; over 50% of the remaining ship population accounts for less than 3% of the ballast oily waste.
Additional oily waste sources are defined. Principal bilge fluid sources are identified, and methods of reducing the volume of bilge fluids generated are explained. Survey data indicate that the major effort of the Navy's oil pollution abatement program should be the development of suitable shipboard oil-water separators.