§4.03-65. Significant harm to the environment.
46 C.F.R. § 4.03-65
Significant harm to the environment means—
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;
In other waters subject to the jurisdiction of the United States, including the EEZ—
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
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
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—
Vessel, floating OCS facility, or MODU location and proximity to land or other navigational hazards;
Weather;
Tide current;
Sea state;
Traffic density;
The nature of damage to the vessel, floating OCS facility, or MODU; and
Failure or breakdown aboard the vessel, floating OCS facility, or MODU, its machinery, or equipment.
Notes, amendments, and revision history
Amendments
[USCG-2000-6927, 70 FR 74676, Dec. 16, 2005, as amended by USCG-2013-1057, 91 FR 39485, June 30, 2026]
Authority
Authority: 43 U.S.C. 1333; 46 U.S.C. 2103, 2303a, 2306, 6101, 6301, 6305, 56311, and 70034; Department of Homeland Security Delegation No. 00170.1, Revision No. 01.4. Subpart 4.40 issued under 49 U.S.C. 1903(a)(1)(E).
Source
Source: CGD 74-119, 39 FR 33317, Sept. 17, 1974, unless otherwise noted.
Amendments
[USCG-2000-6927, 70 FR 74676, Dec. 16, 2005, as amended by USCG-2013-1057, 91 FR 39485, June 30, 2026]