It may be almost three years since the Ballast Water Management Convention (BWMC) entered into force, but from vessel owners to port inspectors, the industry is still getting to grips with its implementation. Testing of ballast water samples remains a major sticking point, and with plenty of ships installing or retrofitting ballast water management systems (BWMS) for the first time, confusion reigns over what performance characteristics should be tested during the initial commissioning.
A key agenda item at the 7th session of the Sub-Committee on Pollution, Prevention and Response (PPR 7) was to update the Guidance for the Commissioning Testing of BWMS (BWM.2/Circ.70). Let’s be clear: the aim of commissioning testing is not to test for compliance with the D2 performance standard on acceptable level of organisms that may be found within discharged ballast water, but rather to verify successful installation of the BWMS. In other words, to demonstrate that all its mechanical, physical, chemical and biological processes are working properly. The updated guidance will include the use of indicative analysis methods to undertake these checks.
Indicative analysis methods rely on proxy measurements, which can yield results more quickly by cutting out the complex sampling and analysis procedures of formal testing. They are based on indicators (such as chlorophyll fluorescence or adenosine triphosphate (ATP) among others), the presence of which correlates to organism concentrations. An indicative test is deemed successful if the discharge samples do not exceed the D2 standard for the size of organisms being checked for (i.e. ≥10 µm and < 50 µm, or ≥ 50 µm). This is, in theory, much more straightforward than compliance testing against the D2 standard which requires direct measurements of organism concentrations. This is generally a complicated and onerous process, which depends on samples collected at source being carefully transported to a laboratory for analysis in order to produce reliable results. Needless to say, all this takes time, effort and a considerable degree of scientific expertise.
The updated Guidance now clarifies that a system’s ability to eradicate microbes (bacteria such as E. Coli and cholera, which endanger human health) does not need to be included in commissioning testing. It also specifies the volume of sample water needed for commissioning tests, who should conduct the testing, and lays down under what circumstances an interim certificate may be issued.
Additionally, the Sub-Committee recommended that references to compliance with regulation D2 are removed from paragraphs relating to BWMS commissioning testing in the Harmonized System of Survey and Certification (HSSC), a system for alleviating the problems caused by survey dates and intervals between surveys which do not coincide.
PPR 7 also looked at a proposed protocol for verifying the performance of ballast water compliance monitoring devices needed to encourage the use of indicative analysis methods in place of more expensive and time-consuming tests based on direct measurement. Aimed primarily at Administrations that want to take a globally consistent approach to ballast water compliance, this protocol is needed since formal approval requirements for such devices are not covered in the BWM Convention. A paper (PPR7/21/7) from IMarEST offering technical comments on the proposed protocol was among five submission considered during the informal discussion. In the paper the IMarEST notes that there are other ballast water compliance monitoring devices such as Total Residual Oxidant (TRO) sensors that are not covered by the scope of the proposed protocol. It suggests the scope of verification testing be balanced to avoid the unintended consequence of delaying availability of verified devices, and agrees that laboratory testing resolves some challenges by providing a more controlled testing environment and verification testing protocols of compliance monitoring devices should consider more than one BWMS technology (i.e. UV, chemical disinfection). Time did not allow for any conclusions to be reached.
The IMarEST continues to undertake work on this topic through its Special Interest Group (SIG) on Ballast Water Management, which you can join here . The Group is planning to host a workshop on compliance monitoring this October, which will explore the ‘lifecycle of commissioning testing’ from installation and testing through to challenges for port State control (PSC). The discussion and key findings will be collated into a thought leadership report for the membership.
Read reports on other key issues from the IMarEST delegation in attendance at PPR7: