The International Maritime Organisation's (IMO) International Convention for the Control and Management of Ships' Ballast Water and Sediments, originally adopted in 2004, has now achieved the required number of signatories and will enter into force on September 8 2017. The convention is expected to have a significant impact on ships engaged in international trade, requiring them to manage their ballast water and sediments to certain minimum standards and to install onboard ballast water management systems.


On discharge of cargo, vessels typically pump sea water into their sea chests as ballast, to increase trim and ensure stability for transit voyages. This water can contain a myriad of biological stowaways, such as bacteria and viruses that are inherent to the port where the ballast water is taken on and are then released into the water of the next port where cargo is loaded. While ballast water is essential for safe and efficient shipping operations, it can pose serious ecological, economic and health problems, due to the multitude of marine species that it carries. For example, ballast water has been the principal cause of cholera epi­demics killing thousands of people and foreign species of algae and jellyfish have been shown to disrupt local species, causing sub­stantial economic losses to local fishing industries.

Ballast water convention

In response to such problems, the International Convention for the Control and Management of Ships' Ballast Water and Sediments was established to prevent, minimise and ulti­mately eliminate the risks to biodiversity, the environment and human health arising from the transfer of harmful aquatic organisms, through the improved management of ballast water and sedi­ments.

Entering into force this year, the convention will force shipowners to make significant investments in installing compli­ant ballast water management systems. However, upcoming national regulations may also impose further, more stringent, requirements on owners. For example, the United States has already implemented sepa­rate ballast water treatment regulations with higher standards than those of the convention. Among other things, the United States requires that parasites be killed immediately when the ballast water is emptied, while the IMO convention requires only that the organism's reproductive ability be damaged, prevent­ing it from establishing itself in a new area.

The IMO's Marine Environment Protection Committee met in late October 2016 to discuss concerns among shipowners that the IMO standards imposed by the convention may not be sufficiently robust to ensure com­pliance with the more stringent regula­tions imposed by certain nations and that an IMO approved system under the convention may not meet, for example, US requirements. The committee adopted revised guidelines for approval of ballast water management systems and rec­ommended that these guidelines be adopted into the convention, and that ballast water systems installed on ships on or after October 28 2020 com­ply with the revised guidelines.

Consequences for shipowners

The convention will apply to all inter­nationally traded vessels that:

  • are registered in states that are parties to the convention; or
  • operate in the waters of such member states.

Submersibles, floating crafts and platforms, floating storage units and floating production, storage and offloading units will also be sub­ject to the convention. However, as a rule, the convention will not apply to vessels that operate only within the territorial waters of their flag state.

Many countries have already adopted national legislation to imple­ment the convention.

Once the convention enters into force this autumn, all vessels to which the convention applies must eventually be equipped with an IMO-approved ballast water treatment technology. For existing tonnage, the date of compliance with the so-called 'D-2 standard' will coin­cide with the next renewal date of a vessel's International Oil Pollution Certificate (this is usu­ally renewed every five years). However, any new ships with a keel laying date after September 8 2017 will be required to have a ballast water treatment system installed at delivery. In the transitional period between the convention entering into force and the D-2 standard being phased in for all vessels, ballast water must be handled in accordance with the water exchange routines set out in the so-called 'D-1 standard'. As stated above, the more stringent requirements of the revised guidelines must be complied with by October 2020.

New opportunities for suppliers

As frustrating as it might be for shipown­ers, the current situation has spurred the development of new technology and it is believed that shipowners will soon have a wider array of ballast water systems which are both IMO and US compliant. Several suppliers have grasped this business opportunity and are in the process of being evaluated – and hope­fully approved – by the US authorities.

The estimated cost for shipowners installing approved ballast water management system will be anywhere from $1 million to $5 million per vessel. The cost will depend on the type of vessel involved, but hopefully the increased com­petition among suppliers will help to drive down costs. In any case, it is essential that shipowners stay on top of the rapid developments in both regulation and tech­nology.

For further information on this topic please contact Øyvind Axe, Cecilie Koch Hatlebrekke or Anne Celine Troye at Wikborg Rein by telephone (+47 55 21 52 00) or email (, or The Wikborg Rein website can be accessed at

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