BWMS commissioning test and surveys (BWM.2/Circ.70/Rev.1)

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Type approval proves that a treatment design works on a test rig. It does not prove that the unit bolted into your engine room, with your pipework, your sampling point and your harbour water, works. That is what the commissioning test is for, and it has been mandatory since 1 June 2022.¹ It is not a formality: members of the Global TestNet reported to IMO that about one in five commissioning tests they had carried out was non-compliant, mostly on the largest organisms (50 micrometres and above), although detailed analysis after a failed indicative test often showed the discharge was in fact compliant.⁸

After commissioning, the system has to keep working for the rest of the ship’s life. In the 2025 port state control campaign the most common deficiency, and the main cause of detentions, was a BWMS that was not operational.¹⁰ This lesson follows a BWMS from installation to renewal: the commissioning test, the surveys, the records and maintenance, and what the review approved in 2026 will add.

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In this lesson

Try it: A BWMS from installation to renewal
In plain words
In detail
What the rules say
Flag and class notes
Key numbers
What inspectors find
Questions people ask
Quiz: 6 questions

Sources

1 IMO Resolution MEPC.325(75), Amendments to the BWM Convention (commissioning testing of ballast water management systems and form of the IBWM Certificate), adopted 20 November 2020, in force 1 June 2022, operative paragraphs 3 to 5 and annex paragraphs 1 and 2 (regulation E-1.1.1 and E-1.1.5). https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MEPCDocuments/MEPC.325(75).pdf
2 IMO BWM.2/Circ.70/Rev.1, 2020 Guidance for the commissioning testing of ballast water management systems, 9 December 2020, annex paragraphs 1 to 5. The English text was not available to us online; paragraphs read in the German official translation published in VkBl. 2022 No. 8, p. 238. https://www.umwelt-online.de/recht/gefahr.gut/see/mepc/bwm2_70r1.htm
3 IMO Resolution MEPC.300(72), Code for Approval of Ballast Water Management Systems (BWMS Code), adopted 13 April 2018, annex paragraphs 4.17 to 4.20 and 8.2 to 8.3. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MEPCDocuments/MEPC.300(72).pdf
4 International Convention for the Control and Management of Ships’ Ballast Water and Sediments, 2004 (BWM/CONF/36), annex regulation E-1, Surveys, paragraphs 1.2 to 1.5. https://mardep.gov.hk/filemanager/en/share/aboutus/pdf/scc/scc_p149a.pdf
5 Isle of Man Ship Registry, Technical Advisory Notice 001-22, Commissioning Tests for Ballast Water Management Systems (BWMS), 8 February 2022. https://iomshipregistry.com/media/kuvmhbry/001-22-commissioning-tests-for-ballast-water-management-systems-bwms.pdf
6 IMO Resolution MEPC.369(80), Amendments to the BWM Convention (Form of Ballast Water Record Book), adopted 7 July 2023, in force 1 February 2025, annex (codes A to H). https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MEPCDocuments/MEPC.369(80).pdf
7 DNV, Mandatory BWMS commissioning test required from 1 June 2022 (technical news). https://www.dnv.com/news/2022/mandatory-bwms-commissioning-test-required-from-1-june-2022-225958/
8 DHI Maritime Tech (E. Chua, G. I. Petersen, T. Madsen), Commissioning testing of Ballast Water Management Systems: best practice for sampling and analysis, technical note, 15 September 2022. https://ballastwater.dhigroup.com/wp-content/uploads/2022/11/Commissioning-testing-of-BWMS-best-practice-for-sampling-and-analysis.pdf
9 ABS, Regulatory News: IMO MEPC 84 Brief, 1 May 2026, section Amendments to Regulation E-1 (Surveys). https://ww2.eagle.org/content/dam/eagle/regulatory-news/2026/ABS-MEPC-84-Brief.pdf
10 Tokyo MOU Secretariat, Press release: Preliminary results of the CIC on Ballast Water Management 2025, 17 March 2026. https://www.tokyo-mou.org/press-releases/2026/03/17/preliminary-results-of-cic-on-ballast-water-management-2004
11 IMO Resolution MEPC.290(71), The experience-building phase associated with the BWM Convention, adopted 7 July 2017, operative paragraph 4. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MEPCDocuments/MEPC.290(71).pdf
12 IMO BWM.2/Circ.42/Rev.2, 2020 Guidance on ballast water sampling and analysis for trial use in accordance with the BWM Convention and Guidelines (G2), 9 December 2020. Listed by IMO; contents index of the German official translation at https://www.umwelt-online.de/recht/gefahr.gut/see/mepc/bwm2_42r2_in.htm
13 Mediterranean MoU Secretariat, Press release PR3-2026 on the CIC on the Ballast Water Management Convention, 2 April 2026. https://www.medmou.org/Documents/PR3-2026.pdf
14 Black Sea MoU Secretariat, Press release: Preliminary results of the CIC on Ballast Water Management, 19 February 2026. https://bsmou.org/downloads/press-releases/BS%20MoU%20Press%20Release%20CIC%20on%20Ballast%20Water%20Management.pdf

Free awareness training. Al Safwan Marine is not an approved training provider, so no certificate is given, and these courses are not a qualification. They don't replace STCW training, manufacturer training or the certification technicians need for this work. The manufacturer's manual and your flag's rules always come first.

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