This is the final post in a six-part series of blogs on Maritime Commons to provide updates and information about the Coast Guard’s ballast water regulations and implementation.
From the desk of Rear Adm. Paul Thomas, assistant commandant for prevention policy
Among the many tangible environmental benefits, the promulgators of ballast water regulations expect that setting a ballast water discharge standard, or BWDS, will ensure the timely development of innovative commercial ballast water management technologies. Thus far, treating ballast water to meet the BWDS has proven to be a significant challenge. The path to U.S. system type-approval will not be an easy one; however, the Coast Guard remains convinced that it is achievable. In this last blog, I’ll describe the process for obtaining a type-approval; here I will highlight some of the challenges associated with ballast water management system type-approval itself.
Challenge #1: System scaling
Test data for ballast water management system, or BWMS, cannot necessarily be “scaled” or extrapolated linearly. This means, for example, that a system tested and approved at a flow rate of 500 m3/hr cannot be assumed to be equally effective at a flow rate of 1000 m3/hr by simply scaling the components necessary to increase flow rate. Unfortunately, the performance of larger systems cannot be easily predicted based on the performance of smaller systems, and vice-versa.
This is a challenge for most BWMS manufacturers who want to offer a range of models that are constructed to handle different ballast water discharge flow rates. Some manufacturers plan to offer as many as 20 different-sized models covering several orders of magnitude in treatment capacity – for example, from 40 to 4,000 m3/h. Without a solid and scientific method to scale test results, manufacturers will be required to subject each model to the full suite of type-approval tests. This will greatly increase the time and cost required for approval of a “family of systems.”
There is a need to identify a practicable, but scientifically defensible, approach for determining the applicability of scaling methods in type-approval testing. Some administrations have approved numerous models of BWMSs on the basis of land-based tests of one-sized unit, and shipboard tests of a different sized unit. But to date, there has been inconsistent use and transparency of scaling methods. This represents a significant technical challenge to ensuring the availability of type-approved systems suitable for a range of ship sizes. I look forward to further work clarifying testing protocols and scaling in the revision of the International Maritime Organization G8 guidelines.
Challenge #2: Testing and type approval of alternate components
Similarly, a BWMS tested and approved with one set of components cannot be assumed to be equally effective with alternate components. Current type-approval procedures require that the entire BWMS be tested in a specific configuration with specific equipment. Land-based testing must be conducted in three different salinities: five test runs, each in fresh, brackish and marine water, with an additional five shipboard tests, for a total of 20 test runs. Additionally, 50 hours of operation and maintenance evaluation are required.
As a result, a BWMS that uses three different types of interchangeable filters would be required to undergo 60 test runs in order for all three filters to be type-approved. Costs and time required for the 60-test series could impede the progress of the type-approval program in this type of scenario.
Manufacturers of BWMS need to be able to change components within the treatment system in order to produce, install and easily maintain these systems onboard ships. This is particularly important in filtration systems because manufacturers offer options for several reasons, including greater flexibility in fitting BWMS into existing ships and greater supply chain availability. Different filter designs and details of construction may result in different efficacies in removing organisms. Additionally, the flow rates and hydraulic conditions of water exiting different filters may be different. These parameters are important because they affect the performance of subsequent treatment components. The issue of interchangeable parts and components may also be a concern for other BWMS features, including UV reaction chambers.
Challenge #3: Updates and new system configurations
BWMS are new and as yet largely unproven technologies. As such, we should expect that approved systems will be redesigned in both small and possibly large ways to improve treatment efficacy and to reduce treatment and system costs as operators and manufacturers gain more BWMS experience. Ultraviolet lamps may be replaced, power systems may be redesigned, digital logic controllers may be changed and machinery may be re-engineered to reduce the footprint of the system, minimize its energy requirements or optimize other system operating parameters. Under the Coast Guard’s procedures for approving BWMS, any changes to an approved system must be submitted to the Coast Guard in advance, and may require additional testing or evaluation.
Ballast water management systems are complicated engineering systems, so it is not always immediately obvious whether a proposed change will affect performance in treating ballast water. Manufacturers should contact the Coast Guard, per the directions in 46 CFR 162.060-16, well in advance of making a change to determine whether additional testing will be required. In some cases, it may be necessary for the Coast Guard and the manufacturer to enter into detailed discussions about a particular design change before a determination can be made. Failure to follow this requirement may result in suspension or loss of approval for a BWMS. Shipowners should also be aware of this requirement and question manufacturers about whether planned upgrades or replacements of components have been approved by the Coast Guard.
To help address these challenges, the Coast Guard Marine Safety Center is currently evaluating options and is seeking flexibility to allow for the acceptance of paper studies without additional testing. The Coast Guard will continue to work with manufacturers and independent laboratories to identify practical solutions to this challenge. We also look forward to further revisions of the G8 guidelines to address these challenges.
As noted in this series of posts, we have come far in the advancement of ballast water treatment systems to effectively reduce the impact of harmful aquatic invasive species. I believe the best way forward is for all stakeholders to collaborate and bring their collective resources and knowledge together to advance the development and testing of ballast water treatment systems. This is the only way to ensure we have systems which will be successfully installed and maintained onboard ships.
Read the six-part ballast water series:
Part 1: Ballast water series from the Assistant Commandant for Prevention Policy
Part 2: Shedding some light on 2012 ballast water regulations
Part 3: Ballast water – U.S. Regulations compared to International Convention
Part 4: Living vs. viable
Part 5: Ballast water type approval process
Part 6: Ballast water type approval challenges for industry
This blog is not a replacement or substitute for the formal posting of regulations and updates or existing processes for receiving formal feedback of the same. Links provided on this blog will direct the reader to official source documents, such as the Federal Register, Homeport and the Code of Federal Regulations. These documents remain the official source for regulatory information published by the Coast Guard.
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