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Ballast Water Treatment Technology

Water conditions affect type-approval testing

Wed 19 Apr 2017 by Paul Gunton

Water conditions affect type-approval testing

Variations between independent laboratory tests are down to water conditions, say makers and labs

Every application for US Coast Guard (USCG) type-approval has to be submitted via one of its accepted independent laboratories (ILs). There are 862 of them but just five are authorised to handle applications for ballast water management systems (BWMSs), each of them supported by a number of sub-laboratories (see table).

Manufacturers can choose which IL to use and, because of their geography, there are differences between their testing capabilities, Ian Stentiford, global vice president of Evoqua Water Technologies, explained to BWTT.

It is using NSF International and its associated sub-laboratories because “we know the challenge that those laboratories will put on our system.” The water it can access contains sufficient organisms to be certain that “if we can pass under those conditions that our system is going to work in the real world subsequently,” he said.

Asked whether, from their own experience, it is easier to pass tests at some ILs than at others, some suppliers that responded to BWTT’s question were reluctant to comment. “No,” was the short and complete response from Optimarin’s chief executive Tore Andersen.

Joe Thomas, managing director of Wärtsilä Water Systems – which, like Optimarin, is working through DNV GL as its IL – said that Wärtsilä was not aware of any issues with ILs, saying that its focus is “on doing the job properly and thoroughly and this was the main driver behind our choice of IL.”

Marcie Merksamer, vice president of the environmental consultancy EnviroManagement, acknowledged that the two ILs its clients are working with do have differences in their overall processes and how they approach various aspects.  But “one is not necessarily easier or harder than the other,” she said. “I find the process equally challenging with both ILs.”

Mark Riggio, senior market manager for Hyde Marine, said the impression that ILs produce different results “simply isn’t true.” What may differ, however, are the organisms in the various test regions. He cited a paper published in the journal Marine Biology in 2011 that found the results of tests carried out with the CMFDA/FDA test method varied between locations because some may have organisms that create more false positives than others. So any differences are not because some ILs are ‘easier’, he said, but because of differences in the biological make-up at those ILs relative to others.

One of the independent laboratories – Lloyd’s Register – confirmed that water conditions will vary between test centres and this could explain the difference between test results. Flans Kemp, the class society’s type-approval business development manager, told BWTT that there should not be a huge difference between the sub-laboratories “because they all have to meet the same regulation and the IL should ensure that all testing is within the limits of this.”

But he reflected Mr Stentiford’s view, saying “some manufactures are very keen to test their system in very harsh environments, to increase confidence and ensure it works in all conditions.”

Of the five ILs, Lloyd’s Register probably has the second largest market share, he estimated, but said that its share is expanding rapidly. “We are also working to acquire more sub-laboratories so we can offer more test slots to our clients,” he said.

All three of the systems that have obtained USCG type-approval at the time of writing have worked with DNV GL as their IL and its senior principal engineer in its Environmental Protection Unit, Martin Olofsson said in February that it was working with about 20 manufacturers on USCG type-approval.

Asked how the USCG ensures consistency, the Korean Register, which has been an IL since March 2015, explained that the USCG works closely with its ILs. “When actively applying type-approval test criteria, ILs can discuss their requests with the USCG and communicate with other ILs,” it told BWTT. USCG has held a number of conference calls among its ILs and has set up a test panel for ILs to share feedback “on what is possible or not, rational or irrational, seeking ways to improve,” the class society said.

Mr Olofsson also acknowledged the value of these links. The conference calls, for example, have helped to “establish a very good understanding of what USCG requires,” he said.  “Everything is not perfect but we have a fairly good understanding of most of the issues.”

USCG Independent Laboratories and sub-laboratories




NSF International


MERC, GSI, Retlif, ABS, Curtis Strauss



DHI-Denmark/Singapore, Golden Bear, NIVA, Applica, DELTA, Phoenix TestLab, Retlif, TUVSUD, SGS Gihe, Labtest

Korean Register of Shipping


KOMERI, KTL, SGS Giheung Lab, Dt&C.

Control Union Certifications

The Netherlands

IMARES, NIOZ, GoConsult, Dr Matej David Consult, TNO, ABS, GSI

Lloyd’s Register EMEA


DHI Denmark, DELTA, DHI Singapore, TUV SUD PSB Singapore, Phoenix Testlab, SGS Korea, NIVA

Source: USCG Maritime Information Exchange

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