Ballast Water Management – new requirements and operational challenges

This statutory news provides a summary of relevant guidance on various aspects of ballast water management such as on new IMO requirements for biological testing by sampling at commissioning of ballast water management systems and on contingency measures. It also includes recommendations for IOPP re-coupling and handling of typical operational challenges.

DNV GL - Technical and Regulatory News on BWM

Relevant for ship owners and managers.

1. Biological testing by sampling at BWMS commissioning

Biological testing by sampling at ballast water management system (BWMS) commissioning is done to confirm that a BWMS installed on a ship meets the D-2 discharge standard. This is required by Singapore’s administration and is recommended by Panama’s and Bahamas administrations already prior to the entry into force of the amended Regulation E-1 of the BWM Convention, which is on 3 October 2021. This sampling test is required only once, at the commissioning of the treatment system, and shall be completed before the International Ballast Water Management Certificate for D-2 is issued. On the DNV GL website you can find a template covering IMO requirements for samples, testing and reporting.

DNV GL has invited potential test facilities to apply to become accepted by DNV GL to perform biological testing at BWMS commissioning. By the end of 2019, DNV GL will publish on its website a list of accepted test facilities.

To become an accepted test facility, DNV GL will review the test facility’s standard operating procedures (SOP), including detailed step-by step sampling methodology and analysis procedures. Relevant QA/QC procedures for sampling and analysis will also be reviewed.

Analysis methods, including indicative methods, listed in the guidance on ballast water sampling and analysis (BWM.2/ Circ.42/Rev.1) may be applied. A test facility may use a portable test kit, given that the reliability and accuracy of the test kit has been validated.

The use of a test kit by the vessel’s crew or the manufacturer of the treatment system is not, however, an acceptable alternative to biological efficacy testing performed by an independent test facility. Instead, ship owners and operators must contract a test facility for testing or request the BWMS manufacturer or shipyard to arrange testing by an independent test facility. Vessel General Permit (VGP) requirements are applicable only for the USCG. The report “The Vessel Discharge Sample Collection & Analytical Monitoring: A How-To Reference for EPAs, 2013 Vessel General Permit (VGP)” covers the frequency of testing and the parameters to test. Please note that the VGP requirements are different than the IMO requirements for biological testing at BWMS commissioning. If biological testing at BWMS commissioning is already required by the flag administration, DNV GL has instructed its surveyors accordingly.

2. De-coupled IOPP and IOPP re-coupling at BWMS commissioning

On a general note, any requirements for IOPP re-coupling by the flag administration are to be considered. If the vessel’s IOPP was de-coupled in 2017, then usually the D-2 standard becomes due 5 years later at the next IOPP renewal in 2021/2022. In case a vessel has a de-coupled IOPP and the BWMS is fitted before the BWM D-2 due date, the IOPP should remain de-coupled until the scheduled IOPP renewal. In this case, both standards, “D-1 + D-2”, can be ticked off on the BWM certificate until the scheduled IOPP renewal.

The IOPP re-coupling is to be performed in any case by an IOPP renewal survey. To be noted:

  • The first IOPP renewal survey after 8 September 2019 requires the BWMS to be commissioned. By completion of survey D-2 becomes mandatory and only “D-2” shall be ticked off on the BWM certificate.

Questions for IOPP re-coupling shall be addressed to our DATE service.

3. BWMS not operational

A malfunction of the BWMS due to a technical problem or a ballasting operation carried out outside of the system’s performance (e.g. UV intensity or TRO is too low) results in the treated ballast water to not be compliant with the D-2 standard. To prevent unnecessary downtime in port, as well detentions and financial penalties by the PSC, the following steps shall be taken:

  • The vessel shall prepare a proposal for contingency measures and a repair plan. Contingency measures are described in the IMO guidance circular BWM.2/Circ.62, e.g. ballast water exchange according to D-1 standard might be an option.
  • The proposed contingency measure is to be submitted by the vessel to the PSC in the port of destination, and the port state shall agree to proposed actions (ref. IMO guidance circular BWM.2/Circ.62).
  • The flag administration is to be notified about the agreement between vessel and port state and be provided with the repair plan and date of repair directly or via DNV GL. The flag may require conditions and a short-term BWM certificate.
  • If a ship has both standards “D-1 + D-2” ticked off on the BWM certificate, then the exchange by D-1 is the obvious alternative option. Even in this case, the administration should be notified directly or via DNV GL and may require conditions and a short-term BWM certificate.

If advice on statutory requirements is needed and for follow-up by class, please contact DNV GL through our DATE service. Within the present BWM “Experience-Building Phase”, the IMO has advised the flag administrations to report any BWMS malfunction to the IMO with the objective of improving the BWM convention.

4. BWM Plan and contingency measures

DNV GL strongly recommends including a chapter on contingency measures in the BWM Plan (BWMP) with instructions to the crew for what to do in the event of non-compliance. Already for ships sailing under the flag of Singapore and Panama, such a chapter on contingency measures is a flag requirement and must be included in the BWMP.

DNV GL has revised the BWMP template for D-2 with a chapter on contingency measures, and the template 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.

If a chapter for contingency measures in the BWMP is required by the flag administration, DNV GL has instructed its approval sections and surveyors accordingly.

This news has been prepared according to feedback received from the industry during the DNV GL webinar held on 22 August 2019. A recording of the webinar is available here.


DNV GL recommends reviewing and taking action in line with the above guidance. We would particularly like to emphasize the importance of contingency measures and biological testing by sampling.



  • For customers:
    DATE – Direct Access to Technical Experts via My Services on Veracity.
  • Otherwise:
    Use our office locator to find the nearest DNV GL office.
29 November 2021

IMO update: Marine Environment Protection Committee – MEPC 77

The 77th session of the IMO’s Marine Environment Protection Committee (MEPC 77) was held remotely from 22 to 26 November 2021. Highlights include recognition of the need to strengthen the ambitions in the IMO GHG Strategy, adoption of a resolution urging for the use of distillates or other cleaner fuels or technologies to reduce emission of black carbon in or near the Arctic, and revised guidelines on exhaust gas cleaning systems.

  • Maritime
08 November 2021

Anchor losses are on a negative trend – How to improve

There has been a negative trend in the loss of anchors and chains in recent years. The safety, environmental and financial consequences can be severe, and port authorities may hold a vessel responsible for all costs caused by a lost anchor for an unlimited period of time. This technical news focuses on operational challenges, current rules and practices, awareness, lesson learned, and recommendations related to anchor equipment damages/losses.

  • Maritime
11 October 2021

IMO Maritime Safety Committee (MSC 104)

The 104th session of the IMO’s Maritime Safety Committee (MSC) was held remotely from 4 to 8 October. The requirements for watertight doors on cargo ships were harmonized, and the Japanese Quasi-Zenith Satellite System was recognized for the provision of position, navigation, and timing services. The MSC also initiated the development of a goal-based instrument for autonomous ships, and the development of guidance for remote surveys and audits.

  • Maritime
View all