Ballast Water Treatment Systems: Check Your Charterparty


INTERCARGO has highlighted the risk of reduced ballasting transfer rates after fitting ballast water treatment systems. We consider the impact on charterparties.

The forthcoming entry into force of the IMO Ballast Water Convention, and the already in place US regulations, will require many vessels to have ballast water treatment systems installed. INTERCARGO has recently raised awareness on the impact these systems may have on a vessel’s performance. North considers how this affects charterparties and in particular, warranties given in the vessel description clause.

Ballast Water ImageIn their submission to IMO (MEPC 71/INF.20), INTERCARGO discusses a number of areas where the retrofitting of a ballast water treatment system can affect a vessel’s operation. These include ballast transfer performance and bringing increased power demands. With this is in mind, North encourages shipowners to check their charterparties to make sure they reflect any changes in performance.

Effect on Ballasting Transfer Rates

INTERCARGO highlights the probable reduction in a vessel’s ballasting capacity when retrofitting a ballast water treatment system. This drop in performance may be due to the unavailability of treatment systems that can match the throughput of the vessel’s ballast pumps as well as the filters introducing additional pressure drops in the system.  

If a vessel’s ballasting/deballasting performance is reduced following the retrofit of a ballast water treatment system, then we recommend the vessel’s description (and any associated warranties) is amended accordingly. If the charterparty remains unamended, a shipowner may be exposed to a charterer’s allegations of breach of warranty if delays are experienced as a result of the longer time needed for ballasting/deballasting.

Meeting New Power Demands

INTERCARGO also raises the possibility of a vessel being unable to meet the greater power demands of a treatment system. Electro-chlorination and UV systems require significant levels of power. For existing vessels, this demand would not have been factored in at the design stage. North reminds shipowners of the importance of assessing whether or not the vessel has the electrical capacity to power the cargo gear at the same time as the ballast water treatment plant. If the vessel’s power generation capacity prevents the operation of all of its cargo handling equipment (for example cranes or cargo transfer pumps) when the treatment plant is in-line, this can result in delays to the cargo operations and lead to disputes.  

Review the Vessel Description Clause

When installing a ballast water treatment system on an existing vessel, North stresses the importance of thinking about the potential impact on charterparty warranties. The vessel description/warranties may need to be amended to reflect any change in the vessel’s performance.