Ballast water management (BWM) and biofouling

a. From date of entry into force (EIF), 8 September 2017, all ships shall have and implement a BWM Plan (BWMP) and record all ballast water operations in the BWM record book. The BWMP shall be approved by the administration
b. Vessels above 400 GT (excluding floating platforms, FSUs and FPSOs) are subject to a BWM survey and are required to hold a BWM certificate, as per regulations E-1 and E-2.
c. At the first IOPP renewal on or after 8 September 2019 at the latest, vessels shall meet the D-2 standard by having a ballast water treatment system (BWTS) approved, installed and commissioned. From the point of time where a vessel has to comply with D-2, the International Ballast Water Management Certificate will indicate the D-2 method only.

If the vessel is in international voyage and the BWM Convention is applicable as per Article 3 of the convention, the vessel and also floating platforms, FSUs and FPSOs must comply with D-1 (exchange) or D-2 (treatment) regulations. According to the convention, such vessels shall be required to have an approved BWM Plan (BWMP) and a record book. But a BWM certificate is only required if the flag administration has their own national requirements.

The D-2 compliance date for these vessels is the completion of first IOPP renewal after 8 September 2019.

If the vessel does not have an IOPP certificate, then the compliance date is 8 September 2024 at the latest, if not otherwise given by the flag administration.

If the BWM Convention is not applicable as per Article 3, for instance in the case that the vessel is reasonably permanently positioned, then an approved BWMP for the D-1 standard and a BWM record book should be available in the case of single voyages, by following the IMO guidance circular BWM.2/Circ.52/Rev.1.

The Ballast Water Management Plan (BWMP) is the document that details the procedure for the discharge of ballast water and the handling of sediment in accordance with regulation D-1 (exchange), and/or regulation D-2 (treatment), and regulation B-5 (sediment management). Conducting ballast water discharge and the cleaning of sediments in accordance with the BWMP ensures compliance with regulations D-1 or D-2, and B-5.

This plan must be specific to the vessel and equipment and approved for each vessel by the flag administration or Class if authorized. The plan may include procedures for both D-1 and D-2 if the vessel employs both methods, or D-2 only if D-2 is mandatory for the vessel. A chapter for contingency measures in the event that the treatment system malfunctions is recommended. Some flags do require a chapter for contingency measures. DNV has developed a template for the BWMP, which can be found here.

The D-2 standard becomes mandatory for all existing vessels² at completion of the first IOPP renewal on or after 8 September 2019. Vessels keel-laid or having underwent a major conversion after 8 September 2017 (EIF date) shall comply with the regulation D-2 upon delivery.

The intention of the D-2 regulation (treatment) is to prevent the discharge of harmful microorganisms into new locations. However, the convention is open regarding how this can be achieved, such as by discharging the ballast water at a reception facility (reg. B-3.6). The port state should have the final decision as to whether they accept any equivalent to D-2 and allow discharging in their waters. For most vessels, a treatment system will be the best way to comply with regulation D-2. Such a system must be approved by the administration.

Even fresh water used as ballast water shall be treated according to the BWM Convention. Regulation B-3.7 accepts other methods of ballast water management as alternatives, but a fresh water generator is not accepted by the IMO for the D-2 standard.

However, such an alternative method has to be approved according to the MEPC Resolution 206(62), which essentially means the alternatives require type approval according to the G8 guidelines.

As part of the approval process for retrofitting a vessel with a ballast water treatment system, the owner will be required to submit the BWMP for approval with information regarding the treatment system and its application. Until the vessel has to comply with the D-2 standard (at the first IOPP renewal survey after 8 September 2019), the BWMP may list both methods in the BWMP as approved BWM methods. Once the vessel has to comply with the D-2 standard, only the treatment method shall be listed as the approved method. The exchange procedure (D-1) can remain in the BWMP, but may only be carried out as a contingency measure.

DNV has prepared a BWMP template for the D-2 standard, which can be found on our website. This template includes a chapter for contingency measures, which also lists the approved D-1 method. We encourage ship owners to use the BWMP template for D-2 for retrofit projects.

Yes, but the convention is open for exemption for vessels voyaging only between specified ports or locations within the same risk area.

An exemption may be given by parties in waters under their jurisdiction (local authorities). The exempting parties shall communicate the exemption to the IMO. This exemption can be given for a period of maximum five years and is subject to intermediate review (reg. A-4). A full overview of the application procedure is given in the Guidelines for Risk Assessment Under Regulation A-4 of the BWM Convention (G7).

For intra North Sea traffic, the IMO guidance circular BWM.2/Circ.56 gives guidance and defines designated ballast water exchange areas.

Within Norwegian territorial waters and economic zone, the Norwegian national regulation applies.

But when the D-2 standard has become mandatory for the specific ship at completion of the first IOPP renewal on or after 8 September 2019, then even a vessel in intra North Sea traffic and intra Baltic Sea traffic has to comply with the D-2 standard.

A ship operating exclusively under the jurisdiction of one party to the convention, pursuant to Articles 3.2(b) to 3.2(d), may be granted an exemption under regulation A-4 for a single voyage on the condition that the ship performs ballast water exchange in accordance with regulations B-4 and D-1 and an approved BWMP. The requirements of regulation A-4.1.4 (risk assessment) should be addressed to the satisfaction of the countries of origin and destination of the ship.

The IMO guidance circular BWM.2/Circ.52/Rev.1 can be applied with consent of the countries of origin and destination.

Yes, the D-1 standard may be maintained in parallel with the D-2 standard on the BWM certificate until the vessel’s D-2 due date, by completion of the first IOPP renewal on or after 8 September 2019. The precondition is that the BWMP is approved for both D-1 and D-2, or the vessel has two approved BWMPs: one for D-1 and one for D-2.

After that date, only the D-2 standard is applicable on the BWM certificate.

Scenario 1

When: Before the vessel’s D-2 compliance date

Type of BWM certificate on vessel: D-1 certificate

Answer: Not applicable, as the treatment system is not mentioned on the certificate. The vessel shall continue to use the approved exchange procedure (D-1).

Scenario 2

When: Before the vessel’s D-2 compliance date

Type of BWM certificate on vessel: D-2 certificate

Answer: The vessel shall have a repair plan and must contact the port authority and flag state administration immediately to discuss contingency measures (see separate question on contingency measures).

Exchange is a possible contingency measure but must be carried out according to an approved exchange method (BWMPwith D-1 approval). It is therefore recommended to obtain D-1 approval and certification beforehand.

We advise ship owners to follow the IMO guidance circular on contingency measures BWM.2/Circ.62.

If time allows, a vessel without D-1 certification may submit a BWMP, including exchange for approval, to DNV.

Once the BWMP is approved, and DNV receives the Master’s declaration that the BWMP is on board, DNV can issue a new certificate including D-2 and D-1. No survey is needed.

Scenario 3

When: Before the vessel’s D-2 compliance date

Type of BWM certificate on vessel: D-1 and D-2 certificates*

Answer: The vessel has the option to carry out ballast water operations either according to the D-1 or D-2 standard until the vessel’s D-2 compliance date.

When there is a malfunction of the treatment system, the vessel needs to perform exchange until the ballast water treatment system (BWTS) has been repaired.

Nevertheless, if the BWTS has a malfunction, then the BWM certificate is limited to D-1 only and therefore D-2 is not fully applicable. So, any PSC might claim the BWM certificate issued for both D-1 and D-2. Thus, the vessel shall have a repair plan and contact the flag state directly or via DNV for advice regarding the validity of the certificate and conditions to performing exchange.**

We advise ship owners to follow the IMO guidance circular on contingency measures BWM.2/Circ.62.

*Contact DNV with the nature of the BWTS’s malfunction. The convention requires a survey before a repaired BWTS can recommence operation. DNV will determine if a survey is required.

**If the vessel also has the class notation BWM(T), or the Clean design notation, and the treatment system malfunctions, the vessel’s owner must inform class as soon as the BWTS is taken out of service.

Scenario 4

When: After the vessel’s D-2 compliance date

Type of BWM certificate on vessel: D-1 certificate

Answer: Not applicable. The vessel must perform treatment after the D-2 compliance date. A retrofit project must have been organized before the D-2 compliance date for approval of documentation, installation and commissioning. The D-1 certificate is to be withdrawn.

Scenario 5

When: After the vessel’s D-2 compliance date

Type of BWM certificate on vessel: D-2 certificate

Answer: The vessel must contact the port authority and flag state administration immediately to discuss contingency measures (see separate question on contingency measures).

We advise ship owners to follow the IMO guidance circular on contingency measures BWM.2/Circ.62.

Exchange may be offered as a contingency measure but cannot be performed without permission from the port authority and flag state. The vessel must obtain approval of the exchange method before proposing exchange as a contingency measure.

Scenario 6

When: After the vessel’s D-2 compliance date

Type of BWM certificate on vessel: D-1 and D-2 certificates

Answer: Not applicable. The vessel must perform treatment after the D-2 compliance date. The D-1 certificate is to be withdrawn.

Scenario 7

When travelling in US waters

Type of BWM certificate on vessel: D-1 certificate

Answer: The USCG treatment discharge requirements have already entered into force.

A vessel must have applied for an extension in treatment compliance from the USCG in order to operate with exchange only.

Scenario 8

When travelling in US waters

Type of BWM certificate on vessel: D-2 certificate

Answer: The USCG requires that the BWMP contain vessel-specific contingency methods. The BWMP should also include procedures for contacting the Captain of the Port (COTP) and reporting to the National Ballast Information Clearinghouse (NBIC) in the event of a BWTS malfunction

The vessel must contact US authorities as soon as possible and ask for instructions. US regulations require that the vessel inform the nearest COTP, but it is recommended that the destination COTP also be informed.

More information on contingency measures in the USA can be found here.

The vessel must obtain D-1 certification before proposing exchange as a contingency measure.

Scenario 9

When travelling in US waters

Type of BWM certificate on vessel: D-1 and D-2 certificates

Answer: See above for the protocols for contacting US authorities.

The D-1 standard can be offered as a contingency measure. It is the decision of the USCG to accept or reject such a proposal.

The IMO has established a generic guidance in BWM.2/Circ.62 for situations where ballast water to be discharged from a ship is determined to be non-compliant. In such cases, communication between the ship and the port state should occur. The ship and the port state should consider the following as possible contingency measures on a case-by-case basis:

1. Actions predetermined in the BWMP of the ship
2. Discharging ballast water to another ship or an appropriate shipboard or land-based reception facility, if available
3. Managing the ballast water or a portion of it in accordance with a method acceptable to the port state
4. Operational actions,such as modifying sailing or ballast water discharge schedules, internal transfer or ballast water other retention of ballast water on board the ship. The port state and the ship should consider any safety issues and avoid possible undue delays.

Having considered all options above, the ballast water may be discharged in the port or any suitable area, as acceptable to t he port state.

Port state consideration may include environmental, safety, operational and logistical implications of allowing or disallowing the discharge.

The discharge of ballast water is subject to any conditions of the port state. In any case, the ship is required to do its best to correct the malfunction of the BWTS as soon as possible and submit its repair plan to the PSC authorities and the flag state.

The type approval process covers the possibility of toxic discharge according to the IMO and/or USCG standards. Chemical treatment systems are required to satisfy minimum toxicity requirements like all BWTSs.

The requirements related to toxic discharge for different US states are addressed in the 2013 VGP and the US EPA’s Generic Protocol for the Verification of Ballast Water Treatment Technology, known as the ETV Protocol.

The amendments to regulation E-1 of the BWM Convention adopted by MECP 74 requires biological efficacy testing when commissioning a BWTS on board a vessel. This amendment came into effect on 1 of June 2022.

For the biological efficacy testing, a test organization approved by DNV or by an organization/supplier accepted by the flag administration, needs to go on board the ship to take samples. The indicate analysis of the samples is typically performed on board the ship (organism counts have to be carried out within a few hours after the samples were taken). The test shall take into account the Guidance for the commissioning testing of ballast water management systems (BWM.2/Circ.70/Rev.1), as amended.

The commissioning test is successful if the indicative analysis indicates that the discharge samples do not exceed the D-2 standard for the size classes analysed and the self-monitoring equipment indicates correct operation. The DNV surveyor will then be able to issue a full term International Ballast Water Management Certificate. There is no separate certificate for the test itself, but the test results need to be summarized in a report. DNV has published a template for such a report, and the template is available at www.dnv.com/bwm.

A biological test for the IMO is only required once per system onboard, at the commissioning of the BWTS and before the International Ballast Water Management Certificate is issued. Please find in our DNV website a report template covering IMO requirements for testing and reporting.

The commissioning test shall be arranged either with a DNV approved service supplier or by an organisation/supplier acceptable to the Flag Administration. Please refer to the DNV approval finder for test facilities accepted by DNV for biological commissioning testing of BWMS (select “Approval of Service Suppliers” and then “Service Suppliers engaged in testing of Ballast Water Management Systems (validation of biological efficacy at commissioning)” or “Commissioning testing of ballast water management systems (BWMS)”). 

For becoming an approved service supplier for commissioning testing, a test facility is requested to submit their standard operating procedures (SOP) for sampling and analysis as per the IMO guidance for commissioning testing of BWMS (BWM.2/Circ.70/Rev.1). Analysis methods, including indicative methods, listed in the IMO guidance on ballast water sampling and analysis (BWM.2/Circ.42/Rev.1) may be applied. A test facility may use a portable compliance monitoring device, given that the reliability and accuracy of this device has been validated. For further details, please visit our DNV class programmes page to find the “Approval of service suppliers scheme”, document code “DNVGL-CP-0484”. In addition, you can find the template for biological testing at commissioning of BWM here.

The contingency measures chapter is required in the BWMP if the administration of the vessel has decided to implement it or if desired by the owner. DNV strongly recommends to include in the BWMP a chapter on contingency measures instructing crew on the procedure in the event of a BWTS malfunction where D-2 compliance is required. This shall be according to the IMO guidelines as described in the guidance circular BWM.2/Circ.62.

In case of BWTS malfunction, well-planned BWM contingency measures allow ship owners to avoid unnecessary downtime for the vessel. The port authority of destination and the flag administration are usually to be informed about the malfunction of the BWTS.

DNV has prepared a BWMP template for D-2 with a chapter on contingency measures, which can be found here.

If the only change for the BWMP is to include contingency measures, an annex or appendix will be enough to send to class for approval. There is no need to send the approved BWMP for D-2 for re-approval.

There will be no need to send the approved BWMP for re-approval. However, the BWMP can get a note to reflect that after the next IOPP renewal survey, treatment (as per D-2) is the only approved method. If this implies just a small revision to the BWMP, a class surveyor can check and endorse the BWMP during the renewal survey. The approved exchange procedure (as per D-1) can still be in the approved BWMP; but after the IOPP renewal survey, D-1 can only be used as a contingency measure.

As of today the BWM Convention does not allow any bypass unless this is an emergency situation for the vessel. The industry is learning more about these challenges during ballast operations during the experience building phase. A draft circular has been submitted by Liberia, Intertanko and Intercargo (MEPC.76-4) which is still under review and consideration. As soon as there is an outcome of this circular or any other regulatory updates, this FAQ will be updated.

As of today only the Contingency measures circular (BWM.2-Circ.62) is the only official document by IMO.

The BWTSs on DNV-class vessels shall include gas detector sensors. BWTSs that are type approved by DNV already include these sensors. In case of a leakage, a warning should be given and, if necessary, a shutdown should take place. Location installation also requires ventilation arrangements. If the BWTS is in a dedicated room, ventilation changes are required depending on the type of vessel and location.

DNV has not detected any hazardous gas generated by the BWTS type approved by DNV in the ballast water tanks. However, confined space entry precautions are always to be followed before entering a ballast water tank regardless of the BWTS installed.

Additionally, DNV requests a procedure for safe tank entry in the BWMP of a vessel with a system that generates hazardous gases.

Please consult the manual of the BWTS for any troubleshooting procedures in such situations. The treatment system may be operated at a lower flow rate.

In case the treatment system cannot be used for ballasting operations due to filter clogging, and there is untreated ballast water in the tanks, contingency measures must be discussed and agreed upon with the port state of destination where the ballast water is planned to be discharged.

In case ballasting operations were carried out with alarms indicating that the treatment system is operating outside the system’s performance claim (e.g. UV intensity or TRO is too low), the treated ballast water may not comply with the D-2 standard, and contingency measures must be discussed and agreed upon with the port state of destination where the ballast water is planned to be discharged.

Plastic pipe may be used in ballast water management system (BWMS) provided that the following design requirements are complied:

1. Plastic pipes are type approved for its intended service. (for special service in chemical cleaning/or chemical injection system, plastic pipe manufacture shall be consulted for the intended service.) (DNV Rules Pt.4 Ch.6 Sec.2 1.7.5, Sec.9 1.7.5)
2. Plastic pipe shall have low surface flame spread characteristics. (DNV Rules Pt.4 Ch.6 Sec.2 1.7.1)
3. Plastic pipe are fitted with remote isolation valve at connection between ballast water treatment system and main ballast pipe/(or sea inlet/sea outlet if applicable) to prevent uncontrolled flooding of the space where the BWMS (plastic pipe) is located. The isolation valves including actuators, shall be steel material or equivalent and be remotely controlled from outside the space. (DNV Rules Pt.6 Ch.7 Sec.1 3.3.1.2, Pt.4 Ch.6 Sec.3 1.3.10)
4. For plastic pipe installation in hazardous area, plastic pipe shall be type approved for installation in hazardous area which includes electrically conductive characteristics. (DNV Rules Pt.4 Ch.6 Sec.9 1.7.2, Sec.10 4.1.9)
5. If the plastic pipe is part of main ballast piping function (main function), fire endurance test L3 is required for the plastic pipe installation in Engine Room/Pump Room/similar machinery space/etc. (Usually not to be installed in part of main ballast piping system in upper deck/or deckhouse at upper deck) (DNV Rules Pt.4 Ch.6 Sec.2, Table 1 – fire endurance requirement matrix)

For vessels laid up for longer periods (cold lay-up), all statutory certificates are not maintained by periodical surveys, while the class status is maintained by periodical surveys with a limited scope. In the background and in the DNV systems, the normal survey schedule is dormant and will be reinstated with the original dates after the lay-up by performing the periodical surveys due at that time.

Some laid-up vessels have decoupled their IOPP.

In relation to the implementation of the BWM Convention, in any case the installation of the BWTS (D-2 compliance) is mandatory at completion of the first IOPP renewal on or after 8 September 2019; in worst case, immediately at the recommissioning survey after the lay-up.

RSW tanks are not considered ballast tanks by some flag administrations. So the flag administration shall be contacted in this situation. However, if the vessel is using RSW tanks also for stability purposes, with only ballast water inside the tanks, it meets the definition of a ballast tank according to the BWM Convention.

The below is DNV’s interpretation on how fishing vessels may comply with the BWM Convention. DNV recommends ship owners to contact the flag of the vessel in regards to this requirement.

• The RSW tanks, when used as ballast tanks, can only discharge according to the D-1 (exchange) or D-2 (treatment) standards
• When in RSW mode (i.e. containing fish), the tanks are cargo tanks and discharge with regard to the BWM Convention does not need to be considered.
• All other ballast tanks, anti-roll tanks, etc. must follow the BWM Convention as usual.
• Such ships would need to have a BWTS installed. Administrations/class should require a BWMP that explains in detail to the captain when he must use the treatment system.
• The total ballast water capacity as defined in regulation A-1.2 must include the RSW tanks for ships that use them as ballast water tanks in some conditions.