33 CFR §151.69

1. (a)Except for ships operating in the Great Lakes which must comply with section 151.66, when a ship is operating outside of a special area specified in § 151.53, no person may discharge garbage into the sea, except as allowed in paragraphs (b) through (d) of this section.
2. (b)The following allowed discharges of garbage shall only be conducted while the ship is en route and as far as practicable from the nearest land, but never less than—
   1. (1)12 nautical miles for food wastes, except that, such food wastes may be discharged outside of 3 nautical miles from nearest land after they have been processed with a grinder or comminuter specified in § 151.75;
   2. (2)12 nautical miles for cargo residues that cannot be recovered using commonly available methods for unloading. The discharged cargo residues must not be harmful to the marine environment; and
   3. (3)100 nautical miles and the maximum water depth possible for animal carcasses. Discharge shall be conducted in accordance with the applicable International Maritime Organization guidelines.
3. (c)Cleaning agents or additives contained in cargo hold, deck, and external surfaces wash water may be discharged only if these substances are not harmful to the marine environment.
4. (d)Mixtures of garbage having different discharge requirements must be:
   1. (1)Retained on board for later disposal ashore; or
   2. (2)Discharged in accordance with the more stringent requirement prescribed by paragraphs (a) through (c) of this section.