StacksVerified U.S. regulatory reference

33 CFR §157.225

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The master of a tank vessel meeting § 157.10a(b), § 157.10a(c)(2), § 157.10b(a)(2), or § 157.10c(c)(2) shall ensure that—
  1. (a)Before clean ballast in any dedicated clean ballast tank is discharged or transferred, the pump and piping system for conveying the clean ballast are flushed with water;
  2. (b)Before any dedicated clean ballast tank is ballasted, the pump and piping system for conveying the ballast are flushed with water;
  3. (c)Before the pump and piping system of the dedicated clean ballast tanks are used for cargo transfer:
    1. (1)If water in the dedicated clean ballast tanks is used for flushing the pump and piping system, the volume of water for flushing is equal to at least 10 times the volume of the piping to be flushed;
    2. (2)The piping system is drained of fluid; and
    3. (3)The valves under § 157.222(d) are closed;
  4. (d)Flushing water is pumped from a sea chest or a dedicated clean ballast tank through the pump and piping system of the dedicated clean ballast tanks and then to a slop tank;
  5. (e)Clean ballast from each dedicated clean ballast tank is discharged in accordance with § 157.43;
  6. (f)When the pump and piping system are being flushed:
    1. (1)The oil content of the flushing water in the piping system is monitored; and
    2. (2)The pump and piping system are flushed until the oil content of the flushing water in the piping stabilizes; and
  7. (g)If any pump or piping system that is flushed to meet paragraph (f) of this section is used to convey cargo during an emergency, that pump or piping system is flushed again to meet paragraph (f) of this section before being used to convey clean ballast.