Ballast Water Treatment Issues Remain Unresolved

mind the gap

Published Nov 21, 2016 3:01 AM by InBallast

Last month’s IMO Marine Environmental Protection Committee (MEPC) adopted resolution MEPC.253(67) on the review of the guidelines for approval of ballast water management systems (G8) to facilitate entry into force of the Ballast Water Management Convention.
The revised G8 is more prescriptive in some aspects and will require harmonization between administrations to ensure a level playing field for manufacturers and purchasing safety for shipowners. 

Validation of limitations 

The new G8 has called for validation of treatment systems’ operational performance over a wider specified range of temperatures and salinities. Additionally, the determination of potential regrowth and requirements related to holding time has also been included. 

However, the IMO has left it to the Administrations to define related test procedure details without providing too much guidance! This may represent a dangerous loophole if interpretations and procedures are not strictly harmonized between administrations. 

Validating performance during sea trials is very different to what is required for land-based tests. For example, challenge water condition requirements are 10-100 times more stringent at sea.

The revised G8 test scope supersedes that of the U.S. Coast Guard type approval test program by quite some margin. The rationale behind the determination of the new G8 in validating what may be seen as extreme limitations, at any cost, or in practice, the vendors cost – may be questioned. Type tests are very expensive, and regulators should consider the cost efficiency of additional test requirements – what is the real added value especially if the added scope is bridged differently by the various Administrations.  

Equipment Readiness

Equipment readiness evaluation requirements have been introduced to ensure that manufacturers test commercially ready treatment systems and don’t use the type approval program as a platform for research and development.

It is now emphasized that the manufacturer or the test facility must specify how to validate the equipment’s limitations before testing begins. A key aspect here is to validate disinfection doses required by testing the manufacturer’s stated dosage limits.

The readiness evaluation now also includes an assessment of the scaling potential of equipment to cater for larger (or less) ballast water flow rates. The manufactuer is required to identify the most “vulnerable” model from a scaling perspective. This model will then be the subject of testing.

Risk assessments are now required, and identified risk mitigating measures must be implemented.

The control and monitoring system has received more focus. Documentation requirements now include a detailed functional description and a software change handling log.


Operation of a treatment system during type testing is now required to be conducted independently of the manufacturer. In principle, this should be no different from a manufacturer running the system, given that the Administration is present to verify that the system is operated in accordance with provided instructions.

In relation to shipboard testing, all ballast operations during the test period should be undertaken using the system commissioned for the tests so it is not only run for the official tests only. 

Control tank sampling during shipboard testing is no longer a requirement. This is a welcome change for manufacturers who have struggled to keep the ballast piping system clean when running untreated water into and out of control tanks through the same piping as the treated water. 

The down side is that testing facilities will never be able to determine the impact of the tank and holding conditions of untreated water versus that of treated water. This will probably also make it impossible to validate hold time, temperature, regrowth and salinity during shipboard testing. 

Therefore, the IMO should look into the added value of sampling on shipboard tests and perhaps remove this from the protocol. Such a change would be welcomed by the manufacturers who are struggling with many aspects of shipboard testing including finding shipowners willing to accommodate onboard testing, finding valid challenge water, the logistics associated with the testing and the high financial burden.  

Requirements have been introduced to ensure that treatment systems are type tested with one configuration of hardware. Changing major components that could affect efficacy during the testing will result in a need for new testing. This is not new. However, it has probably been practiced differently by different Administrations. 

There are several issues here. Should the introduction of, for example, an alternative total residual oxidant sensor or Ultra-Violet sensor require new testing? This is another issue that needs to be harmonized by Administrations.

The use of standard test organisms is now specified to be supplementary to the organism density of the water, to make up for seasonal variations. The proportion that these standard test organisms contribute to the total density of organisms is to be reported and published for transparency. This is probably because the industry has seen tests being run with a very high fraction of standard test organisms, and the general view is that validation based on treatment of natural organisms is more representative.   

The source of dissolved organic carbon used during land-based testing has received more attention and must now be reported along with its effect on UV transmittance and oxidant demand.

Sampling and testing 

The requirement for three sampling replicates has been changed to one time integrated replicates in line the ETV protocol as applied by the U.S. Coast Guard. There is also a greater focus on assuring a low mortality in the test water independent of the treatment.

Requirements for hazardous gas management have been included. After working with a number of treatment systems that hazardous gas, it has become clear that this had not previously been covered adequately. 

The new G8 introduces design requirements for gas emission handling by requiring, for example, independent shutdown following the detection of failures, redundant detection and dilution equipment. This will result in more attention being paid to systems producing hazardous gas.

The environmental testing to be conducted on treatment systems’ electric and electronic components will now follow testing protocols defined by IACS UR E10, Rev.6, October 2014 instead of an IMO G8 unique test program. Off-the-shelf components can now be used without the need for new type approval testing, and this development should be welcomed by equipment manufacturers.

A greater focus has been placed on the output format of the control system monitoring. A typical log has previously consisted of an XLS file with thousands of monitoring values and without a standard output format. In the new G8 a PDF report that describes each ballasting operation is preferred, with specifications for alarms, failures, dose and other general ballasting details such as volume, time and position to make up a simplified electronic ballast water record book.  

The logs and treatment settings must be tamperproof. Both the standardized output format and the tamperproof requirement provides an easy and credible way of assessing if the ballast water was treated in accordance with the type approval certificate.

Reporting and type approval certificates 

Type approval reports must have greater transparency under the new G8 and should be similar to those written in 46CFR 162.060. In particular, methods of validation, testing and failed or invalid tests must be made clear. 

The Gaps

So what is missing? Overseeing a number of ballast water operations using ballast water treatment systems, we have often been astonished at the disproportional focus on the actual treatment system versus the interfaces to the vessels ballast water distribution system (piping) and the training of the crew in light of actually achieving compliance. 

Improper operation by crew, for example in achieving the correct sequence of valve alignments, and inadequate consideration of the interfacing piping arrangements in light of vessel draught, tank levels, etc. have jeopardized many of these operations and undoubtedly will do so when the Convention is enforced. It doesn’t take much to screw up; assuming the zooplankton concentration of the intake water is 100,000 individuals and that by-pass valves have a 0.1 percent misalignment, it could only take a few seconds of operations before the tank is contaminated.

One would think that this is covered by the Ballast Water Management Plan and would be discovered by the shipboard testing. Unfortunately – they are not. Our experience is that the Plan is insufficient and does not represent as a practicable tool. 

Turning a blind eye to these issues seems irrational given the massive investments made by both manufacturers and regulators in assuring that the actual ballast water treatment system unit functions properly through a very sturdy approval regime.     

InBallast is an independent Ballast Water Management consulting and engineering firm. www.inballast.com

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