environment As the amount of water being loaded and unloaded can be massive, achieving the latter is no easy task, given that the space available onboard for retrofitting an existing vessel is often very limited. There are several systems on the market today, promoting a variety of treatment methods. Most of these combine a mechanical filtering stage with a disinfecting stage of some sort. Both sets of regulations are clear on one issue: all organisms must not in fact be removed from the water – it is enough to render them incapable of reproduction. This is complicated enough, since the organisms that pass through the filter are miniscule and just few of them can render the resulting water ‘out of specification’. The treatment needs can be compared to that for potable water, one of the most strictly regulated water treatment processes in existence. Therefore it comes as no surprise that the world’s largest and most experienced provider of ultraviolet (UV) irradiation treatment of water, Trojan Technologies, joined forces with leading marine solutions provider Wärtsilä to develop IMO and market one of the most interesting ballast water treatment solutions of today. A novel and innovative solution As in most of the systems of the market today, the Wärtsilä solution’s treatment method consists of two stages: a filter stage and a UV disinfection stage. Both stages are in operation during ballasting, that is, when water is pumped into the ballast tanks. First, all larger particles and organisms are filtered out. Then, any remaining organisms are either killed or rendered incapable of reproduction in the second stage. During deballasting, when the water is discharged, only the second, UV stage, is in operation. The actual UV treatment is stateof-the-art, based on one of the best drinking water treatment technologies in the world and optimised for low US Coast Guard phase 1 phase 2 < 10 < 10 < 0,01 / m³ Organisms 10 - 50 μm < 10 < 10 < 0,01 / ml Escherichia coli < 250 < 250 < 126 cfu* / 100 ml Intestinal enterococci < 100 < 100 < 33 cfu* / 100 ml <1 <1 <1 cfu* / 100 ml 2012 2012 2016 *) cfu = colonyforming units Implementation year technical support into the foreseeable future, with all the possible changes and updates to the regulations that seem inevitable? The selection of supplier and/or treatment process is only one of the thorny questions facing ship owners in the coming years. Another, Invasions of new organisms sometimes upset the balance in the receiving ecosystem, with disastrous results Organisms > 50 μm Toxicogenic vibro cholera energy consumption while retaining a secure and high treatment efficiency. Where the novelty of this system is most visible is in the enclosure. Whereas most systems on the market are simply combinations of two or more separate treatment components interconnected Table 1. Regulations in brief. It seems likely that the US Coast Guard regulations will come into force earlier than the IMO regulations, meaning vessels travelling in US waters need to comply earlier than vessels in other areas of the world. with pipes, the Wärtsilä system is fully integrated in a single unit. This allows for an extremely small footprint – only 1.40 square metres for a system capable of treating 500 cubic metres an hour – which is a vital parameter to consider when it comes to retrofitting. Several large shipowners, for example Wallenius and BW Group, have developed or acquired technology to design their own systems, and can then tailor the installation to their specific needs. But for the bulk of the market one key feature will be installation size. The clock is ticking – but it is best to wait For Caribbean ship owners, both USCG and IMO regulations will most probably apply, with the USCG regulations coming into force already in 2012 followed closely by the IMO. The time to select a suitable system is getting shorter, bearing in mind that the USCG regulations are to become even stricter in a few years. So which supplier to select? The question rests on one simple reality. Which one will be able to sustain (possibly even larger) issue will be the delivery and installation capacity available. A huge number of vessels will have to install ballast water treatment systems in the near future and there is a risk that there will be a shortage both of available systems and yard time. So should we choose a system today and get it installed right away in order to be ready in good time? Well, in reality, no. Especially not for vessels in or close to US waters, like most Caribbean ships as well as European and Asian vessels destined for the USA. In Puerto Rico and US Virgin Islands, the US Coast Guard will also be the lead enforcement agency, suggesting that USCG certification is extremely important. But as the US Coast Guard has not yet released final certification guidelines for their regulations, there are at this time no USCG-certified ballast water treatment systems on the market. The clock is ticking. But it is still best to wait. *Martin Thorsson is associated with Wärtsilä Sweden AB CARIBBEAN MARITIME I MAY - SEPTEMBER 2011 39