46 CFR § 4.03-65 - Significant harm to the environment.
Significant harm to the environment means -
(a) In the navigable waters of the United States, a discharge of oil as set forth in 40 CFR 110.3 or a discharge of hazardous substances in quantities equal to or exceeding, in any 24-hour period, the reportable quantity determined in 40 CFR part 117;
(b) In other waters subject to the jurisdiction of the United States, including the EEZ -
(1) A discharge of oil in excess of the quantities or instantaneous rate permitted in 33 CFR 151.10 or 151.13 during operation of the ship; or
(2) A discharge of noxious liquid substances in bulk in violation of §§ 153.1126 or 153.1128 of this chapter during the operation of the ship; and
(c) In waters subject to the jurisdiction of the United States, including the EEZ, a probable discharge of oil, hazardous substances, marine pollutants, or noxious liquid substances. The factors you must consider to determine whether a discharge is probable include, but are not limited to -
(1) Ship location and proximity to land or other navigational hazards;
(3) Tide current;
(4) Sea state;
(5) Traffic density;
(6) The nature of damage to the vessel; and
(7) Failure or breakdown aboard the vessel, its machinery, or equipment.