40 CFR §1700.4

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗

For the following discharges incidental to the normal operation of Armed Forces vessels, the Administrator and the Secretary have determined that it is reasonable and practicable to require use of a Marine Pollution Control Device for at least one class of vessel to mitigate adverse impacts on the marine environment:

(a)Aqueous Film-Forming Foam: the firefighting foam and seawater mixture discharged during training, testing, or maintenance operations.
(b)Catapult Water Brake Tank & Post-Launch Retraction Exhaust: the oily water skimmed from the water tank used to stop the forward motion of an aircraft carrier catapult, and the condensed steam discharged when the catapult is retracted.
(c)Chain Locker Effluent: the accumulated precipitation and seawater that is emptied from the compartment used to store the vessel's anchor chain.
(d)Clean Ballast: the seawater taken into, and discharged from, dedicated ballast tanks to maintain the stability of the vessel and to adjust the buoyancy of submarines.
(e)Compensated Fuel Ballast: the seawater taken into, and discharged from, ballast tanks designed to hold both ballast water and fuel to maintain the stability of the vessel.
(f)Controllable Pitch Propeller Hydraulic Fluid: the hydraulic fluid that discharges into the surrounding seawater from propeller seals as part of normal operation, and the hydraulic fluid released during routine maintenance of the propellers.
(g)Deck Runoff: the precipitation, washdowns, and seawater falling on the weather deck of a vessel and discharged overboard through deck openings.
(h)Dirty Ballast: the seawater taken into, and discharged from, empty fuel tanks to maintain the stability of the vessel.
(i)Distillation and Reverse Osmosis Brine: the concentrated seawater (brine) produced as a byproduct of the processes used to generate freshwater from seawater.
(j)Elevator Pit Effluent: the liquid that accumulates in, and is discharged from, the sumps of elevator wells on vessels.
(k)Firemain Systems: the seawater pumped through the firemain system for firemain testing, maintenance, and training, and to supply water for the operation of certain vessel systems.
(l)Gas Turbine Water Wash: the water released from washing gas turbine components.
(m)Graywater: galley, bath, and shower water, as well as wastewater from lavatory sinks, laundry, interior deck drains, water fountains, and shop sinks.
(n)Hull Coating Leachate: the constituents that leach, dissolve, ablate, or erode from the paint on the hull into the surrounding seawater.
(o)Motor Gasoline and Compensating Discharge: the seawater taken into, and discharged from, motor gasoline tanks to eliminate free space where vapors could accumulate.
(p)Non-Oily machinery wastewater: the combined wastewater from the operation of distilling plants, water chillers, valve packings, water piping, low- and high-pressure air compressors, and propulsion engine jacket coolers.
(q)Photographic Laboratory Drains: the laboratory wastewater resulting from processing of photographic film.
(r)Seawater Cooling Overboard Discharge: the discharge of seawater from a dedicated system that provides noncontact cooling water for other vessel systems.
(s)Seawater Piping Biofouling Prevention: the discharge of seawater containing additives used to prevent the growth and attachment of biofouling organisms in dedicated seawater cooling systems on selected vessels.
(t)Small Boat Engine Wet Exhaust: the seawater that is mixed and discharged with small boat propulsion engine exhaust to cool the exhaust and quiet the engine.
(u)Sonar Dome Discharge: the leaching of antifoulant materials into the surrounding seawater and the release of seawater or freshwater retained within the sonar dome.
(v)Submarine Bilgewater: the wastewater from a variety of sources that accumulates in the lowest part of the submarine (i.e., bilge).
(w)Surface Vessel Bilgewater/Oil-Water Separator Effluent: the wastewater from a variety of sources that accumulates in the lowest part of the vessel (the bilge), and the effluent produced when the wastewater is processed by an oil water separator.
(x)Underwater Ship Husbandry: the materials discharged during the inspection, maintenance, cleaning, and repair of hulls performed while the vessel is waterborne.
(y)Welldeck Discharges: the water that accumulates from seawater flooding of the docking well (welldeck) of a vessel used to transport, load, and unload amphibious vessels, and from maintenance and freshwater washings of the welldeck and equipment and vessels stored in the welldeck.