Ships conducting ballast water management must discharge fewer than 10 viable organisms per cubic metre that are greater than or equal to 50 micrometers in minimum dimension and fewer than 10 viable organisms per millilitre that are less than 50 micrometers in minimum dimension and greater than or equal to 10 micrometers in minimum dimension; and discharge of the indicator microbes must not exceed the specified concentrations.
The indicator microbes, as a human health standard, include, but are not limited to:
1. Toxicogenic vibrio cholerae (O1 and O139) with less than 1 colony-forming unit (cfu) per 100 millilitres or less than 1 cfu per 1 gram (wet weight) zooplankton samples.
2. Escherichia coli – less than 250 cfu per 100 milllilitres.
3. Intestinal enterococci – less than 100 cfu per 100 millilitres.