Ballast Water Management Convention

The BWM Convention, adopted 2004 and in force 8 September 2017, requires ships to manage ballast water and sediments to limit the transfer of invasive aquatic species. The D-1 standard sets a volumetric exchange requirement; the D-2 standard sets discharge limits on viable organism counts (fewer than 10 per cubic metre for organisms 50 micrometres or larger). Since 8 September 2024 all ships in scope must meet D-2, normally through a type-approved treatment system. Ships carry a ballast water management plan, a record book, and an International Ballast Water Management Certificate.