Over thirty per cent of all installed ballast water treatment systems (BWTSs) fail Port State Control (PSC) D-2 compliance inspections, despite 95 per cent of systems having successfully passed commissioning tests. This follows from data analysed by Global TestNet.

Article supplied by BIO-UV Group.

Information submitted by Global TestNet to the International Maritime Organization’s Marine Environment Protection Committee (MEPC) 82, which took place in October 2024, revealed that 29 to 44 per cent of operational systems are failing to remove invasive species in the >50µm range, with more than 100 organisms of this size routinely found in every 1 m3 of treated water.

The D-2 standard of the Ballast Water Management (BWM) Convention, which entered fully into force on 8 September, requires ships to discharge ballast water with fewer than ten viable organisms per 1 m3 that are at least 50 µm in size.

Global TestNet – an association of testing organisations set up in 2010 under the GloBallast Partnership – also reported instances where more organisms were found in discharged water than in inlet water.

Also read: Bawat and Damen in joint venture for ballast water treatment

From contamination to human error

According to the findings, the most common reasons for non-compliance were contamination of the ballast water tank from mixing treated and untreated waters or improperly opening/closing valves; organism regrowth due to insufficient and infrequent cleaning of the ballast water tanks; and human error due to insufficient system knowledge, maintenance, and training.

‘These results show that even if a vessel with a type-approved ballast water treatment system passes initial commissioning tests, the BWM system alone cannot assure against non-compliance,’ says Charlène Ceresola, BIO-UV Group’s BWT Project Manager, who is currently participating in the BWM Convention Review as a Member of the French Delegation to the IMO Ballast Water Review Group.

She adds: ‘When a BWMS is properly installed, a high efficacy in removing organisms is achieved (99.9 per cent), but IMO MEPC reports have acknowledged that this efficacy may not be sufficient to constantly meet the D-2 discharge standard. Compliance tests often fail due to the presence of organisms in the tank or water contamination. If operators do not fully understand the impacts of BWM on board, and if bypassing cleaning procedures for ballast tanks occurs frequently, non-compliance will be unavoidable.’

Poor record keeping, crew training and missing certificates

The most frequent deficiencies reported by the Paris Memorandum of Understanding (MoU) on Port State control also related to poor ballast water record book-keeping, inadequate crew training, system unfamiliarity, and invalid or missing certificates.

Of the 907 ballast water non-compliance deficiencies reported by the Paris MoU in 2023, 760 related to record-keeping and administration (58 per cent), BWTS system and system knowledge (sixteen per cent), and certification (16.9 per cent), resulting in 33 ship detentions. This year to date, 505 ballast water management deficiencies have been reported, resulting in seventeen ship detentions.

Also read: Optimarin supplies ballast water treatment for ASW Frigates

IMO updates Appendix II

Regarding the record-keeping and reporting to administrations, BIO-UV Group is now advising ship operators that IMO has updated Appendix II of the BWM Convention (form of BWRB) to clarify entries to be recorded.

‘We are encouraging BIO-SEA system operators to refer to the new guidance on ballast water record-keeping and reporting (due to enter into force on 1 February 2025), published in BWM.2/Circ. 80 to safeguard against port delays and detentions,’ says Ceresola. ‘While there remains a two-year grace period for treatment performance issues, ships can still be delayed for poor administration.’

Maintenance and training

Maintenance and crew training are also areas where ships can be detained. Ceresola: ‘There is certainly a need for strengthening maintenance and system knowledge, and this will be part of the package of amendments IMO is preparing. Shipowners want their systems to be in good working order, but how do you ensure this once the manufacturer has installed the system and left the ship, or is no longer in the market?’

‘Fit and forget is certainly not a BIO-UV Group policy, of course,’ she adds. ‘But there is agreement amongst ship operators and regulators that routine compliance checks are required. It is essential to assess whether systems efficiently prevent harmful aquatic organisms and pathogens from being discharged into the oceans.’

Convention Review Plan

The IMO’s Convention Review Plan for the BWMS experience-building phase aims to address the thirteen priority issues identified at MEPC 80. The amendments package is expected to be completed by the end of 2026, with implementation taking place twelve to eighteen months afterward. The primary focus areas include BTWS maintenance, crew training, and addressing challenging water conditions.

Picture: Charlène Ceresola, BIO-UV Group’s BWT Project Manager, participating at MEPC 82, as a member of the French Delegation to the IMO Ballast Water Review Group.

Also read: Kooiman equips first two Amasus vessels with ballast water treatment systems