Ballast Water Management


Ballast water contains a variety of organisms, such as marine and coastal plants and animals from different regions of the world. If taken up in one place and released in another, some organisms may survive and prosper in their new environment. These “non-native species” can have a serious ecological, economic and public health impact on the receiving environment. To combat the problem of invasive species from ballast water, the IMO adopted the International Convention for the Control and Management of Ships’ Ballast Water and Sediments in 2004. On 8 September 2017, the convention entered into force.

Implementation of the IMO convention

The convention stipulates two standards for discharged ballast water. The D-1 standard covers ballast water exchange while the D-2 standard covers ballast water treatment. The convention requires either D-1 or D-2 standard after entry into force.

There will be a transitional period from the entry into force to the first IOPP renewal survey* after 8 September 2019 in which ballast water exchange (reg. D-1) can be employed. After the IOPP renewal survey, vessels will be required to meet the discharge standard D-2. The latter is most commonly met by installing an approved Ballast Water Management System (BWMS). Ships constructed** after entry into force will be required to have a treatment system installed at delivery.

*The renewal survey is the survey according to regulation E-1.2 of the BWM Convention, which is defined as the date of the renewal survey according to MARPOL Annex I, Reg. 6.2 (IOPP) by a separate resolution.
** Constructed means when: the keel is laid, construction identifiable with the specific ship begins,  assembly of the ship has commenced comprising at least 50 tonnes or 1 percent of the estimated mass of all structural material, whichever is less, or the ship undergoes a major conversion.

IMO Requirements

For ship owners and operators, this means that they must now have an International BWM Certificate. 

To obtain the certificate, a vessel must have a BWM Plan addressing procedures for BW exchange, BW treatment or both. If a BWM System is installed, then approved technical documentation for the BW treatment system installation must be available on board. Lastly, a Ballast Water record book is required, and the vessel must employ the chosen ballast water management method.


USCG Regulations

Besides the IMO convention, ships sailing in US waters are required to employ a type-approved BWMS which is compliant with USCG regulations. DNV has extensive experience in type approval of BWMS for the IMO and the USCG.

Now that the convention has entered into force, ship owners must be compliant with the IMO, and the USCG if necessary. We at DNV are committed to ensuring a smooth transition into compliance with the requirements of the regulations for ship owners, manufacturers, yards and ports alike. Please also visit our Frequently Asked Questions page for further details.


WEBINAR on demand: Updated BWM Convention – be ready for the discharge standard D-2 (August 2019)

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Ballast Water Management services

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BWM plan template for D-2

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BWM plan template for D-1

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Biological testing at commissioning of BWM

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Biofouling Management Plan template

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IMO on Ballast Water Management

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IMO guidelines for Biofouling Management

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