This page contains a Flash digital edition of a book.
Two steps forward… more confusion and a missed opportunity. The BWM saga continues


A Coldharbour BWTS installation in progress


into millions of dollars. Moreover, it is not hard to predict that ships which continue to fail tests, carrying systems which ports states have identified as unreliable in treating ballast water, are more likely to attract attention.


Despite claims to the contrary from some quarters, no BWM system can prevent regrowth, including the Coldharbour BWTS. However, as a result of designing a system that is optimised for larger ships with very high ballast capacities and typically longer ballast legs and providing a solution which is operated during the ballast voyage, treatment can be scheduled for a suitable point in the ballast leg to ensure that the vessel arrives within 24 hours of the completion of treatment.


In addition, although the IMO guideline covering regrowth is 5 days (USCG is only 1 day), the Coldharbour system showed no evidence of significant regrowth after 10 days or more during official land based testing for its IMO Type Approval (awarded Feb 2015 by UK MCA, supervised by Lloyds Register).


The implementation schedule


Limitations (SDL) revision implies that re‐growth should be taken into account, as all systems must treat to a discharge standard, there is nothing explicitly laid down in the new guidelines to be of real help to owners.


Peter Stehouwer of the Royal Netherlands Institute for the Sea has compared 6 different ballast water treatments and demonstrated that although microorganism populations are heavily depleted by BWMS, no system discharges sterile water. Since BWMS removes the organisms that prey on and control algae and bacteria, copepods and phytoplankton for example, once they are removed any small but living residual microbes regrow unhindered feeding on the organic remains of dead predators. Furthermore, regrowth usually results in far larger populations in the discharge ballast water than originally existed. These high concentrations permit the emergence of totally new strains as organisms exploit the genetic exchange mechanisms that result in antibiotic resistance. For ships on longer ballast voyages (10 days or greater), the risk of experiencing significant organism regrowth is high. Systems which treat at uptake (i.e. inline systems) must provide a solution for retreatment prior to discharge (if retreatment is technically possible at all) or risk fines from Port State Control when ballast fails to meet D‐2 discharge standards. Significant delays could follow if de‐ballasting is refused, unloading time‐slots are surrendered and the ship is forced to sail to international waters to conduct ballast exchange. It is important to keep in mind that the regulations create a discharge standard for organism numbers in ballast water, and not a treatment standard as some have claimed. It is simply not a defence for owners to have carried out a treatment by a certificated system at the beginning of a voyage if regrowth of organisms during the voyage means that the numbers in the discharge waters exceed the maximum permitted at the end of the voyage.


The problem of regrowth represents a significant economic risk to ship owners. Over time, loss of revenues and fines could run


36 Society of Maritime Industries Handbook & Members’ Directory 2017


An alternative D‐2 implementation schedule has been proposed whereby any ships with their IOPP survey taking place after 8th Sept 2017 but before 8th Sept 2019 will be required to fit a system at the following IOPP survey. This proposal may be considered at MEPC 71 in May 2017. Rumours are that several MEPC members are lukewarm about this proposal, given that it has already taken an embarrassing amount of time for IMO to secure Ratification of the Convention and would prefer that the current timetable whereby compliance to D‐2 is required at the first IOPP renewal survey after 8th September 2017 be retained.


As it stands, Coldharbour is advising its customer that, unless there is a change, the existing schedule definitely still applies. This is important because owners must make plans in good time if they are to effect a successful retrofit program for their vessels. Adopting a ‘wait and see’ approach could end up becoming a costly mistake!


Phil Hughes, Commercial Manager, Coldharbour Marine Ltd


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60