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Clean living

An old concern makes a return; but help is at hand

Before scrubbers, ballast water treatment systems and methane slip, there was the oily water separator - an oft-overlooked but vital aspect of MARPOL compliance. Now, Port State Control authorities are reopening a case long thought of as a settled issue – to shipowners’ cost.

Much of the recent MARPOL discussion has surrounded discharge from ballast water and scrubbers; indeed, the diverse landscape now emerging in new types of fuels, too – each with their own unforeseen side-effects – serves to make regulatory compliance a challenge. But some problems have always affected even the most modern and most meticulously well-maintained ships.

One of these is water residue and runoff from oil-based lubricants, used in the engine room, collecting in the bilge – a fact of life on every ship. These consist of engine lubricating oils, hydraulic fluid, antifreeze and other substances which would be damaging to the environment if merely tossed overboard.

Those who have been in the maritime industry for some time will recall, 15 years ago, a furor surrounding oily water separators (OWS), the device for filtering the oil and sludge residues from ships’ bilge water.  This is one of the most vital components on a ship for preventing oil pollution; but is less often considered, because it is thought to be a settled issue.

However, shipowners are discovering this is not always the case.

Reopening old wounds

In 1994, IMO resolution MEPC.60 (33) entered effect. It specified that each ship would have to carry equipment capable of discharging a water effluent with a maximum permissible oil content of 15 parts per million (ppm).

Then, in 2005, IMO resolution MEPC.107(49) entered force, specifying that a new type of alarm system be used. The IMO did not demand shipowners with older tonnage fit an entirely new system; only, to test their older model for accuracy every five years, as part of the renewal survey for their ship’s international oil pollution prevention (IOPP) certificate.

Currently, SKF has some 2,000 of these older-model systems on board vessels, more than capable of fulfilling the IMO’s mandate of 15ppm or less. There are many more systems from other manufacturers as well.

Modern systems, like the Turbulo-MPB (“Mechanical Phase Breaker”), have a two-phase treatment regime, more than capable of 15ppm. Oily bilge water is passed through the separator via a helical rotor pump and the separated oil is drained by means of automatic level control. The next phase includes filtration, where a filter element, such as the HycaSep element, is used for screening the finest oil particles. Older systems, however, only comprise the first phase, with older and less accurate monitoring systems.

Take nothing for granted

However, there are concerns surrounding port state control. In recent years, regimes have become stricter, with many more vessels being inspected and detained. Special attention is often reserved for older vessels. Whether this is warranted is a matter of debate; but nonetheless, there are markers of an older ship which stand out on its IOPP renewal form. In recent years, one of these has been a pre-2005 OWS system.

This is a concern; no shipowner wishes to become a target for inspections, however confident they may be that no deficiencies will be found. Today’s regulations involve an onslaught of operational changes to be made in order to keep up with requirements, and additional scrutiny is rarely welcomed even when a ship’s OWS is perfectly adequate for the task at hand.

But retrofitting new equipment to bring a pre-2005 OWS up to a modern standard is relatively straightforward, consisting of fitting a filter stage, and an improved suite of sensors. Requiring only a small additional engine-room footprint, this task can be performed in drydock in a matter of days, or even underway with a riding squad; any manufacturer’s system can be modified in this way, as well.

Worth the risk?

Some realms of regulatory compliance are tougher to keep pace with than others. Increasingly robust inspection and survey regimes make this a more challenging business environment for shipowners than ever, and the repercussions of a detention – off-hire time, blacklisting, and reputational damage – are not to be taken lightly.

In light of this, then, comparing the price of an affordable and fast retrofit, against the potentially much higher cost of being singled out for inspections, makes for rather less challenging arithmetic than it might have been back in 2005.

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