With 8 September 2019 – the next important date in the International Convention for the Control and Managements of Ships’ Ballast Water and Sediments 2004 (Convention)’s implementation timeline – fast approaching and requiring more of the existing fleet to comply with the more stringent D-2 standard under the Convention, this article serves as a useful reminder of the circumstances where the Convention applies and also of the requirements for compliance.

The Convention was adopted by the International Maritime Organization (IMO) in 2004 and came into force on 8 September 2017 (Implementation Date); as of April 2018 the Convention had been ratified by 69 countries, representing over 75% of the world merchant shipping tonnage.

The aim of the Convention is to manage the ships’ ballast water (by mechanical, physical, chemical and biological processes, either singularly or in combination) in order to remove, render harmless, or avoid the uptake or discharge of harmful aquatic organisms and pathogens within ballast water and sediments. With the increase of international trade, shipping was one of the major factors leading to aquatic organisms being introduced to different environments and possibly threatening the existing marine ecosystems.


Under the Convention ‘ship’ is defined as a ‘vessel of any type whatsoever operating in the aquatic environment and includes submersibles, floating craft, floating platforms, Floating Storage Units (FSUs) and Floating Production Storage and Offloading Units (FPSOs).’

The Convention applies to ships entitled to fly the flag of a contracting party (and those that operate under the authority of that party irrespective of flag) which use ballast water during international voyages. The Convention also makes clear that contracting parties are to apply the requirements of the Convention as necessary to ensure that no more favourable treatment is given to ships flying the flag of no signatory parties.

There are limited exceptions to the Convention including those for (i) ships not designed or constructed to carry ballast water, (ii) ships of a contracting party which only operate in waters under the jurisdiction of that party (unless that party designates otherwise), (iii) any warship, naval auxiliary or other ship owned or operated by a state and used, for the time being, only on government non-commercial service and (iv) permanent ballast water in sealed tanks on ships, that is not subject to discharge.

Requirements - documentation

As of the Implementation Date, all ships that fall under the Convention are required to carry certain documentation and comply with the applicable ballast water management standard, namely either the ballast water exchange (regulation D-1) or the performance (regulation D-2) standard.

In terms of documentation, ships are required to carry:

  • A ballast water management plan – this is to be approved by the flag state, be specific to each ship and contain certain information/details including:
    • safety procedures for the ship and the crew associated with ballast water management
    • a detailed description of the actions to be taken to implement the ballast water management requirements and supplemental ballast water management practices
    • the procedures for coordinating shipboard ballast water management that involves discharge to the sea with the authorities of the state into whose waters such discharge will take place
    • designation of the officer on board in charge of ensuring that the plan is properly implemented
  • A ballast water record book – this may be an electronic record system, or integrated into another record book or system, with record book entries to be maintained on board the ship for a minimum of two years after the last entry has been made. Entries should be made on the following occasions:
    • When ballast water is taken on board
    • When ballast water is circulated or treated for management purposes
    • When ballast water is discharged into the sea
    • When ballast water is discharged to a reception facility
    • When ballast water is discharged accidentally or in other exceptional circumstances
  • An international ballast water management certificate – this applies only to ships of and over 400GT and excludes floating platforms, FSUs and FPSOs. The certificate is issued by the flag state after the ship has been surveyed and confirms that the ballast water management on the ship is compliant with the Convention.

Requirements – ballast water management standards

As of Implementation Date, all ships are required to comply with the exchange standard (D-1) and new ships with the performance standard (D-2), the latter usually requiring the fitting of an approved ballast water management system. There is a staged move for ships towards the D-2 standard with the implementation timeline as provided under the Convention (Regulation B-3) and subsequently amended by meetings of the Marine Environment Protection Committee (MEPC) by reference to the ship’s International Oil Pollution Prevention Certificate (IOPPC).

D-1 standard

This standard requires ships to exchange their ballast water in the open seas as to reduce the risk of introducing potentially harmful aquatic organisms to the new environment during the operation. According to the Convention, ships performing ballast water exchange in accordance with Regulation D-1 are to undertake this with an efficiency of at least 95% volumetric exchange of ballast water being exchanged in the open seas.

To meet that standard, whenever possible, a ship should conduct such ballast water exchange at least 200 nautical miles from the nearest land and in water at least 200 metres in depth. If that is not possible, such exchange is to be undertaken as far from the nearest land as possible, and in all cases at least 50 nautical miles from the nearest land and in water at least 200 metres in depth.

The Convention makes clear that a ship should not be required to deviate from its intended voyage, or delay the voyage, in order to comply with the above requirements.

When the above requirements are not met, the relevant port state may designate areas, in consultation with adjacent or other states, as appropriate, where a ship may conduct ballast water exchange.

The Convention also makes clear that compliance with the above is not required if the master reasonably decides that such exchange would threaten the safety or stability of the ship, its crew or its passengers because of adverse weather, ship design or stress, equipment failure or any other extraordinary condition.

D-2 standard

This standard specifies the maximum amount of viable organisms allowed to be discharged. More specifically, ships conducting ballast water management in accordance with this regulation shall discharge:

  • less than 10 viable organisms per cubic metre greater than or equal to 50 micrometres in minimum dimension
  • less than 10 viable organisms per millilitre less than 50 micrometres in minimum dimension and greater than or equal to 10 micrometres in minimum dimension

and the discharge of the indicator microbes shall be:

  • less than 1 colony forming unit (cfu) per 100 millilitres of toxicogenic Vibrio cholerae
  • less than 250 cfu per 100 millilitres of Escherichia coli
  • less than 100 cfu per 100 millilitres intestinal enterococci

In order to comply with the D-2 standard most vessels will be required to have a suitable ballast water management system, which will either be installed at the time of the vessel’s construction or be retrofitted. A system installed to meet the D-2 standard must be safe in terms of the ship, its equipment and the crew and also approved in accordance with Regulation D-3 by the relevant flag state.

MEPC 72 in April 2018 adopted the IMO Code for Approval of Ballast Water Management Systems (Code) which revokes the 2016 Guidelines for Approval of Ballast Water Management Systems (Guidelines) previously adopted, even though the contents of the Guidelines will become mandatory through the Code when it comes into force on 13 October 2019. According to MEPC 72’s resolution, ballast water management systems approved not later than 28 October 2018, taking into account the Guidelines, may be installed on board ships before 28 October 2020; after that date any installation should comply with the Code.

More details regarding the Convention’s implementation timeline, actions that the port state control authorities can take in case of breach and considerations for installing a suitable ballast water management system can be found in part two.