33 CFR § 157.15 - Slop tanks in tank vessels.

---
identifier: "/us/cfr/t33/s157.15"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "33 CFR § 157.15 - Slop tanks in tank vessels."
title_number: 33
title_name: "Navigation and Navigable Waters"
section_number: "157.15"
section_name: "Slop tanks in tank vessels."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "O"
subchapter_name: "POLLUTION"
part_number: "157"
part_name: "RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "33 U.S.C. 1903; 46 U.S.C. 3703, 3703a (note); Department of Homeland Security Delegation No. 0170.1. Subparts G, H, and I are also issued under section 4115(b), Pub. L. 101-380, 104 Stat. 520; Pub. L. 104-55, 109 Stat. 546."
regulatory_source: "CGD 74-32, 40 FR 48283, Oct. 14, 1975, unless otherwise noted."
cfr_part: "157"
---


# 157.15 Slop tanks in tank vessels.

(a) *Number.* A tank vessel must have the following number of slop tanks that comply with the requirements of this section:

(1) A new vessel of less than 70,000 tons DWT and an existing vessel must have at least one slop tank.

(2) A new vessel of 70,000 tons DWT or more must have at least two slop tanks.

(b) *Capacity.* Slop tanks must have the total capacity to retain oily mixtures from cargo tank washings, oil residue, and ballast water containing an oily mixture of 3 percent or more of the oil carrying capacity. Two percent capacity is allowed if there are—

(1) Segregated ballast tanks that meet the requirements in § 157.09, § 157.10, § 157.10a, or § 157.10b; or

(2) No eductors arrangements that use water in addition to the washing water.

(c) *Design.* A slop tank required in this section:

(1) Must minimize turbulence, entrainment of oil, and the creation of an emulsion by the use of separate inlet and outlet connections; and

(2) May carry bulk oil when not being used as a slop tank.

[CGD 74-32, 40 FR 48283, Oct. 14, 1975]

For  citations affecting § 157.15, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at