Ballast Water Treatment: Industry Needs Clarity

MEPC71

By MarEx 2017-07-04 19:48:30

The IMO's Marine Environment Protection Committee meeting (MEPC 71) is now under way at IMO Headquarters in London (July 3-7).

A key item on the agenda is the implementation of the Ballast Water Management Convention, which will enter into force on September 8, 2017. The Committee will consider draft amendments to the Convention which will determine the implementation schedule for installations of ballast water management systems.

Following ratification by Greece last week (on June 26), the Convention has been ratified by 60 countries, representing 68.46 percent of world merchant shipping tonnage. 

MarEx spoke to Susanna Wyllie, Global Proposals Manager for Balpure, De Nora's ballast water treatment system to analyze implementation issues from an equipment supplier perspective.

What needs to be decided at MEPC 71?

The essential thing that the industry needs from the next MEPC meeting is clarity. For both shipowners, operators and ballast water providers to be able to effectively plan for the next few years, there needs to be an absolute decision concerning timelines and clarity of what will be permitted. If both a two-year extension to the enforcement of the standards and the decoupling of the IOPP certificate are permitted at this MEPC, the IMO will essentially be pushing controls on damaging invasive species five-to-seven years down the road. This would mean over 20 years between the adoption of the IMO convention in 2004 and compliance for some vessels.

Over 50 ballast water treatment systems have IMO Type Approval. Several systems already have U.S. Coast Guard approval with many more, including Balpure, going through the approval process and certified under the U.S. Coast Guard Alternate Management System. It is evident that the industry is well prepared to meet the entry into force deadline with full compliance, if required to do so.

Industry body Intercargo has highlighted some of the technical and operational difficulties faced by bulk carrier owners in meeting the requirements of the IMO Ballast Water Management Convention and U.S. legislation. Is the availability of type approved systems sufficient for bulkers? e.g. varying ballast flow rates, available space and electrical power requirements.

In short, yes. There are several type-approved and proven systems that are applicable to bulkers and meet the needs of large vessels with high flow rates and limited or complex space requirements. There are currently a number of commissioned and operating De Nora Balpure systems meeting comparable needs. 

De Nora is the originator and patent holder of electrochlorination disinfection of ballast water through the slipstream method. This method means that only a 0.5 to one percent of the water entering the ballast line needs to be channelled into the treatment system. This is ideal for vessels with large ballast tanks and high pumping rates, as the hypochlorite used to treat the water is created in the slipstream and introduced to the full volume of ballast water. 

In addition, slip stream systems don’t require the intake volume of other ballast water treatment systems. They can be made up of small sub-assemblies allowing the system to be mounted away from the ballast lines, with major equipment installed in the engine room. These sub-assemblies also mean that Balpure has one of the most flexible footprints on the market, enabling owners to adapt the system to the space requirements of each vessel and designed to fit through most hatch doors, allowing quick and easy retrofit installations.

How can the industry address the issue of gravity discharged top side ballast tanks?

The question of gravity discharged top side tanks is unfortunately clear-cut; discharging this way will simply not be allowed under the IMO Ballast Water Management Convention. Simply put, owners and operators need to be able to demonstrate that their system meets the IMO’s discharge standards, and it is very difficult to prove that water has been treated and neutralized if a gravity discharged topside tank is used. 

The challenge is very real for bulker owners with this type of ballast layout, but there have been five to 10 years to find solutions and remedy this problem - that action hasn’t been taken is not the fault of the legislation. 

It is also worth noting with a Balpure system, gravity discharge is still possible if there is common piping to demonstrate compliance.

What is the effect of chemically treated water on tank and hull coatings?

This is a frequent concern of owners and operators and, happily, one that is totally unfounded. Owners and operators should feel assured that the receipt of IMO type approval means that the system has proven its ability to meet compliance without damaging the vessel, including the tank or hull coating. Further to that, De Nora has independently verified with two different manufacturers that there is no noticeable impact of its hypochlorite on tank coatings. We tested to a much higher concentration than that used to treat ballast water in practice, and there has been no evidence of any negative effect.

We would also suggest a little perspective on chemically treated ballast water. The strength of ballast tank sodium hypochlorite generated by a slip stream electrochlorination system like Balpure is 1.5 percent. Commercially available sterilizing fluid for baby bottles is two percent sodium hypochlorite and household bleach is five percent.

Thank-you Susanna.

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.