46 CFR § 4.03-65 - Significant harm to the environment.

---
identifier: "/us/cfr/t46/s4.03-65"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 4.03-65 - Significant harm to the environment."
title_number: 46
title_name: "Shipping"
section_number: "4.03-65"
section_name: "Significant harm to the environment."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "A"
subchapter_name: "PROCEDURES APPLICABLE TO THE PUBLIC"
part_number: "4"
part_name: "MARINE CASUALTIES AND INVESTIGATIONS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "14 U.S.C. 102; 43 U.S.C. 1333; 46 U.S.C. 2103, 2303A, 2306, 6101, 6301, 6305, 70034; 50 U.S.C. 198; DHS Delegation 00170.1, Revision No. 01.4. Subpart 4.40 issued under 49 U.S.C. 1131(a)(1)(E)."
regulatory_source: "CGD 74-119, 39 FR 33317, Sept. 17, 1974, unless otherwise noted."
cfr_part: "4"
---


# 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;

(2) Weather;

(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.

[USCG-2000-6927, 70 FR 74676, Dec. 16, 2005]