### Question
Can you define what ballast water exchange means?


### Answer
**Ballast water exchange** is defined as the following in *33 U.S.C. § 1322*:

> the replacement of water in a ballast water tank using 1 of the following methods:


(i) Flow-through exchange, in which ballast water is flushed out by pumping in midocean water at the bottom of the tank if practicable, and continuously overflowing the tank from the top, until 3 full volumes of water have been changed to minimize the number of original organisms remaining in the tank

#### Citation:
  - *33 U.S.C. § 1322*
  - Heading: **CHAPTER 26-WATER POLLUTION PREVENTION AND CONTROL > SUBCHAPTER III-STANDARDS AND ENFORCEMENT**

