A Third of All Ballast Water Treatment Systems Aren't Working Properly: Report

Charlène Ceresola of BIO-UV discussed the issue at last month's MEPC meeting at the IMO. Image Credit: BIO-UV. 

Almost a third of all installed ballast water treatment systems are not currently working adequately, according to manufacturer BIO-UV.

More than 30% of the systems currently fail port state control D-2 compliance inspections, despite 95% of them having successfully passed commissioning tests, the company said in an emailed statement.

Ballast water treatment systems remove biological organisms from ballast water, to avoid the spread of invasive marine species and comply with IMO regulations.

Data supplied to the IMO in October by Global TestNet indicates 29-44% of operational systems currently fail to remove invasive species in the >50µm range, with more than 100 organisms of this size routinely found in every 1m3 of treated water, BioUV said.

The D-2 standard of the BWM Convention, which entered fully into force in September, requires ships to discharge ballast water with fewer than 10 viable organisms per 1m3 that are at least 50µm in size.

"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," Charlène Ceresola, BIO-UV Group's BWT Project Manager, said in the statement.

"When a BWMS is properly installed, a high efficacy in removing organisms is achieved (99,9%) 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 Ballast Water Management on board, and if bypassing cleaning procedures for ballast tanks occurs frequently, non-compliance will be unavoidable."