Ballast water management convention – what’s new?


The International Convention for the Control and Management of Ships' Ballast Water and Sediments - a key international measure for environmental protection that aims to stop the spread of potentially invasive aquatic species in ships’ ballast water entered into force on 8 September 2017. As at September 2017, the treaty has been ratified by more than 60 countries, representing more than 70% of world merchant shipping tonnage. 

The convention requires ships to manage their ballast water to remove, render harmless, or avoid the uptake or discharge of aquatic organisms and pathogens within ballast water and sediments. For the ship's personnel the main questions are: what do we need to know about it and how is it going to affect ship’s operational routine?

For those curious IMO published a list of FAQ’s. 

Which ships does the convention apply to? 

The convention applies to ships registered under contracting Parties to the BWM Convention, which take up and use ballast water during international voyages. Ships registered under a flag which hasn’t ratified the BWM Convention may not be issued with the relevant certificates. However, port States which are Parties will expect the ships to comply with the requirements of the Convention, so as to ensure no more favourable treatment is given to such ships.

What do ships need to do, now the treaty is in force?

From the date of entry into force, ships in international traffic are required to manage their ballast water and sediments to a certain standard, according to a ship-specific ballast water management plan. Ships have to carry: 

A ballast water management plan - specific to each ship, the ballast water management plan includes a detailed description of the actions to be taken to implement the ballast water management requirements and supplemental ballast water management practices; 

A ballast water record book - to record when ballast water is taken on board; circulated or treated for ballast water management purposes; and discharged into the sea. It should also record when ballast water is discharged to a reception facility and accidental or other exceptional discharges of ballast water; and 

An International Ballast Water Management Certificate (ships of 400 gt and above) – this is issued by or on behalf of the Administration (flag State) and certifies that the ship carries out ballast water management in accordance with the BWM Convention and specifies which standard the ship is complying with, as well as the date of expiry of the Certificate.

What are the ballast water management standards? 

There are two ballast water management standards (D-1 and D-2). The D-1 standard requires ships to exchange their ballast water in open seas, away from coastal areas. Ideally, this means at least 200 nautical miles from land and in water at least 200 metres deep. By doing this, fewer organisms will survive and so ships will be less likely to introduce potentially harmful species when they release the ballast water. 

In cases where the ship is unable, at least 50 nm from the nearest land and in water at least 200 m in depth, or in a designated ballast water exchange area and is required to be conducted in accordance with regulation B-4.

Ships performing Ballast Water exchange in accordance with this regulation shall do so with an efficiency of at least 95 percent volumetric exchange of Ballast Water.

For ships exchanging Ballast Water by the pumping-through method, pumping through three times the volume of each Ballast Water tank shall be considered to meet the standard. Pumping through less than three times the volume may be accepted provided the ship can demonstrate that at least 95 percent volumetric exchange is met. 

The D-2 standard specifies the maximum amount of viable organisms allowed to be discharged, including specified indicator microbes harmful to human health. From the date of entry into force of the BWM Convention, all ships must conform to at least the D-1 standard; and all new ships, to the D-2 standard. In order to comply with D-2 standard ship needs to have an approved ballast treatment system.

From 8 September 2017: 

New ships must meet the D-2 standard.

Existing ships must meet at least the D-1 (ballast water exchange) standard; they may also choose to install a ballast water management system or otherwise meet the D-2 (discharge) standard but this is not mandatory until the corresponding compliance date.

Eventually, all ships will have to conform to the D-2 standard. For most ships, this involves installing special equipment to treat the ballast water. IMO Member Governments have agreed on an implementation timetable for existing ships, linked to the ship's International Oil Pollution Prevention Certificate (IOPPC) renewal survey. 

IOPPC Renewal survey after 8 September 2019

A ship undergoing a renewal survey linked to the ship's International Oil Pollution Prevention Certificate after 8 September 2019 will need to meet the D-2 standard by the date of this renewal survey. 

IOPPC Renewal survey between 8 September 2017 and 8 September 2019 

- If the previous IOPPC renewal survey was between 8 September 2014 and 8 September 2017, then the ship must comply with D-2 standard by this renewal survey. 

- If the previous IOPPC renewal survey was before 8 September 2014, then the ship can wait until the next renewal survey (which will be after 8 September 2019). 

By the 8 September 2024 all ships must meet the D2 standard of the BWM convention as per the infographic below.

Sediment Management for Ships

Not only ballast water, but also sediment from ballast tanks has to be disposed properly. The volume of sediment in a ballast tank should be monitored on a regular basis.

Regulation B-5.2 of the Convention requires that ships should, without compromising safety or operational efficiency, be designed and constructed with a view to minimize the uptake and undesirable entrapment of sediments, facilitate removal of sediments and provide safe access to allow for sediment removal and sampling


Removal of sediment from ballast tanks should preferably be undertaken under controlled conditions in port, at a repair facility or in dry dock. The removed sediment should preferably be disposed of in a sediment reception facility if available, reasonable and practicable. 

When sediment is removed from the ship’s ballast tanks and is to be disposed of by that ship at sea, such disposal should only take place in areas outside 200 nm from land and in water depths of over 200 m.


The requirements of Convention, shall not apply to: 

(1) the uptake or discharge of Ballast Water and Sediments necessary for the purpose of ensuring the safety of a ship in emergency situations or saving life at sea; or 

(2) the accidental discharge or ingress of Ballast Water and Sediments resulting from damage to a ship or its equipment: 

(.1) provided that all reasonable precautions have been taken before and after the occurrence of the damage or discovery of the damage or discharge for the purpose of preventing or minimizing the discharge; and 

(.2) unless the owner, Company or officer in charge wilfully or recklessly caused damage; or 

( 3 ) the uptake and discharge of Ballast Water and Sediments when being used for the purpose of avoiding or minimizing pollution incidents from the ship; or 

( 4 ) the uptake and subsequent discharge on the high seas of the same Ballast Water and Sediments; or 

( 5 ) the discharge of Ballast Water and Sediments from a ship at the same location where the whole of that Ballast Water and those Sediments originated and provided that no mixing with unmanaged Ballast Water and Sediments from other areas has occurred. If mixing has occurred, the Ballast Water taken from other areas is subject to Ballast Water Management. 

How will ships’ compliance be checked? 

Ships may be subject to port State control in any port or offshore terminal of a Party to the BWM Convention. This inspection may include verifying that there is onboard a valid Certificate and an approved ballast water management plan; inspection of the ballast water record book; and/or sampling of the ship’s ballast water, carried out in accordance with the Guidelines for ballast water sampling (G2). 

However, the time required to analyse the samples shall not be used as a basis for unduly delaying the operation, movement or departure of the ship. 

As per Article 12 of the convention, when a ship is unduly detained or delayed under BWM regulations it shall be entitled to compensation for any loss or damage suffered. 

More questions?

That’s basically the information we can find on IMO website. Also, there might be some additional questions important for seafarers, answers for which can be found in BWM convention itself and in MEPC.252(67) Guidelines for Port State Control under the BWM convention.


Our courses

Seafarers' Rights

Ship's Cook Refresher Course

High Voltage Equipment

Time Management


Related articles

INMARSAT is not the only GMDSS satellite service! New amendments to SOLAS Chapter IV on GMDSS

INMARSAT is not the only GMDSS satellite service! New amendments to SOLAS Chapter IV on GMDSS

The International Maritime Organization (IMO) has revised the SOLAS Chapter IV requirements for the Global Maritime Distress and Safety System (GMDSS) to reflect advancements in technology and to...

17 January 2024
E-mail etiquette in maritime industry: best practices

E-mail etiquette in maritime industry: best practices

Email is one of the most common and important forms of communication in the modern world, especially for businesses that operate across borders and oceans. However, email etiquette can vary depending...

24 July 2023
STCW Maritime Security Training - which one do you need?

STCW Maritime Security Training - which one do you need?

Maritime security is a vital aspect of the shipping industry, as it protects the lives and property of seafarers, passengers, cargo, and port facilities from various threats and risks. To ensure...

24 May 2023