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UV ballast water treatment close to US approval

UV ballast water treatment close to US approval

Shipowners have found it increasingly difficult to comply with ballast water treatment regulations in the US. But there’s good news on the horizon thanks to DESMI’s newest UV-based solution

Ultraviolet radiation (UV), which counters microorganisms by rendering them unable to reproduce, is the preferred method for today’s ballast water treatment systems. This robust and reliable technology has been widely adopted by shipowners required to comply with the IMO’s ballast water management regulations.

But receiving type approval for UV-based systems to comply with US rules has been far more difficult. Now, however, smoother waters lie ahead, as Danish manufacturer DESMI A/S expects its own UV solution to be one of the first such systems approved.

Fast-tracked US regulations
In April 2012, The United States Coast Guard (USCG) announced regulations aimed at reducing the importation of invasive species into US waters, a nuisance whose costs are estimated to run into billions of dollars each year. These new regulations arrived somewhat later than the corresponding IMO convention, but while the IMO rules have yet to be ratified, the US equivalent was published and adopted in the same year.

The USCG regulations apply to ships depending on their size and date of construction. Essentially, ballast water discharged must contain fewer than ten 50-micrometre or larger organisms per cubic meter, and fewer than ten per millilitre for organisms less than 50 micrometres and greater than or equal to 10 micrometres. At the same time, the regulations lay out specific demands for a range of particularly undesirable microorganisms.

To comply, shipowners could theoretically choose among a range of technologies, including but not limited to ultrasound, deoxygenation, chemical disinfection and last but not least, ultraviolet radiation. First, however, each treatment methodology and system must be approved by the USCG – and that’s where the difficulty starts.

A sense of urgency
From the outset, the high costs of invasive microorganisms have lent urgency to the USCG’s implementation process. But, like most regulatory measures, getting everything in place to enforce the new rules takes time. Meanwhile, many shipowners are today faced with demands to comply, yet are powerless to do so until a system has been type-approved.

To deal with this paradox, the USCG has announced a number of Alternate Management Systems (AMS), which provide for temporary acceptance of systems that have already been approved by non-US authorities, provided they live up to IMO standards, and can be shown by the USCG to be at least as effective as a ballast water exchange procedure. Such systems, however, are only a stop-gap measure.

Wanted: Dead or alive?
At the heart of the problem is the fact that, while the US regulations require organisms discharged to be “dead, rendered harmless or removed”, the ETV test protocol, which the US rules incorporate by reference, only specify a test method to detect if organisms are dead or alive. The protocol does not include any means to detect if organisms have otherwise been “rendered harmless”. And UV does exactly this by destroying their capability of reproducing. So currently approved tests for evaluating the effectiveness of ballast water treatment systems give a resounding thumbs down to UV results.

Of course, the USCG isn’t oblivious to the advantages of UV-based systems. So in 2013, it initiated a workgroup to address the problem. Key to the activities of the group has been the development of the Most Probable Number (MPN) testing methodology, which involves taking samples of discharged water and examining them for organism population growth over a period of days or weeks. Clearly, sterile organisms will eventually die out altogether. The MPN methodology itself is nothing new, having been used for testing drinking water over the past few decades.

DESMI’s strategy
Rasmus Folsø, CEO of DESMI Ocean Guard, a company within the DESMI group, explains his strategy for achieving type approval:

Since we started on the IMO path in 2009, we have developed systems with a valid IMO certification in all salinities. Knowing how important the US is to many of our customers, when we started the testing of our RayCleanTM system, we were fortunate we took the decision to achieve both IMO and Coast Guard approvals. We expected, in fact, that the USCG regulations may eventually become the gold standard for global certification – and we were keen to be at the forefront of any such development.”

Following its hunch, DESMI became a first-mover, developing test plans with DNV, the classification society appointed by the USCG to perform type testing. Earlier this year, all testing had been successfully concluded, and documentation was completed, allowing DESMI to file its application for type approval in the US.

Now it’s a just a matter of time,” says Rasmus Folsø, confident that USCG approval for his company’s UV solution – and a clear strategy for shipowners seeking compliancy – is just over the horizon.

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