Ballast Water Treatment System

A ballast water treatment system is shipboard equipment that disinfects or otherwise treats the water a ship takes on for stability before it is discharged, so as to stop the ship carrying harmful aquatic organisms from one part of the ocean to another. The problem was documented as early as 1903, when Asian phytoplankton appeared in the North Sea carried in ballast water, but only drew serious international attention as shipping volumes grew through the later twentieth century; the International Maritime Organization first took up ballast water in 1988, and the resulting Ballast Water Management Convention, adopted in 2004, entered into force on September 8, 2017 once 30 countries representing 35 percent of world merchant tonnage had ratified it, with 86 parties by 2021. New ships must carry a treatment system meeting the Convention D2 treatment standard, and existing ships faced a phased deadline running to September 2024, at an installation cost that can reach roughly five million dollars per vessel.