Using water as ballast for empty or part-laden ships is not a new development having been in use for more than 200 years. Ballast is not just used to adjust draught but also to help trim to enable safe and efficient operation of ships under a variety of conditions including cargo shift and water ingress.
Few of those that were innovative enough to make use of water instead of solid ballast could have thought that their idea was later to be considered as ecologically unsound.
Background to the Convention
It was not until the 1982 UN Convention on the Law of the Sea (UNCLOS) that control of species transfer became a topic of international concern. Some ten years later, the 1992 United Nations Conference on Environment and Development (UNCED) requested the International Maritime Organization (IMO) to consider the adoption of appropriate rules on ballast water discharge.
The ballast water treatment convention was to be a further 12 years under discussion before its final Adoption in February 2004. Adoption did not mean that the convention automatically came into force; for that to happen there needed to be ratification by at least 30 states representing 35% of the world merchant shipping fleet by gross tonnage. The first trigger point was reached quite early but the 35% fleet figure was only achieved on 7 September 2017 when Finland ratified.
Several nations have not so far ratified the convention and neither has the US although it has introduced its own federal regulation very similar to that of the IMO Convention. The US regulation has meant that the potential for individual states in the union introducing their own local laws has been averted but all vessels intending to trade to the US will now have to fit a treatment system.
Although it is generally accepted that the requirements of the convention will become standard practice, parties to it are given the right to take, individually or jointly with others ‘more stringent measures with respect to the prevention, reduction or elimination of the transfer of harmful aquatic organisms and pathogens through the control and management of ships’ ballast water and sediments, consistent with international law’. However, this has been tempered by adding a clause saying that ‘Parties should ensure that ballast water management practices do not cause greater harm than they prevent to their environment, human health, property or resources, or those of other States’.
Structure of the Convention
The structure of the convention includes 22 Articles that govern the operation of the convention, a number of regulations spread over five categories and a set of 14 guidelines each covering a different topic.
The five areas of regulations are:
- Section A – General provisions
- Section B – Management and control requirements for ships
- Section C – Special requirements in certain areas
- Section D – Standards for ballast water management
- Section E – Survey and certification requirements for ballast water management
The list of guidelines and the topics covered are:
- G1. Guidelines for sediment reception facilities
- G2. Guidelines for ballast water sampling
- G3. Guidelines for ballast water management equivalent compliance
- G4. Guidelines for ballast water management and development of ballast water management plans.
- G5. Guidelines for ballast water reception facilities
- G6. Guidelines for ballast water exchange
- G7. Guidelines for risk assessment under regulation a-4 of the convention
- G8. Guidelines for approval of ballast water management systems
- G9. Procedure for approval of ballast water management systems that make use of active substances
- G10. Guidelines for approval and oversight of prototype ballast water treatment technology programmes
- G11. Guidelines for ballast water exchange design and construction standards
- G12. 2012 guidelines on design and construction to facilitate sediment control on ships
- G13. Guidelines for additional measures regarding ballast water management including emergency situations
- G14. Guidelines on designation of areas for ballast water exchange
Methods of compliance
The Convention — which applies to all vessels which carry ballast water — allows for two means of meeting the requirements and these are contained in Section D – Standards of Ballast Water Management. The methods are Ballast Water Exchange (Regulation D-1) or Ballast Water Management (Regulation D-2); with the latter requiring some form of treatment system. The convention has detailed requirements for both methods.
Regulation D-1 Ballast Water Exchange Standard
Ships performing Ballast Water exchange shall do so with an efficiency of 95% volumetric exchange of Ballast Water. For ships exchanging ballast water by the pumping-through method, pumping through three times the volume of each ballast water tank shall be considered to meet the standard described. Pumping through less than three times the volume may be accepted provided the ship can demonstrate that at least 95% volumetric exchange is met.
The D-1 Ballast Water Exchange method was conceived as an interim measure that would be allowed only to existing ships with ballast capacities up to and including 5,000m3 built before 2009 and for vessels with ballast capacities over 5,000m3 built before 2012. Those ships allowed to perform ballast exchange as a means of compliance would be permitted to do so only for a limited period depending upon construction date and ballast capacity.
By 2017 the permission was supposed to expire for all vessels and only ballast water management would be permitted. Delay in the ratification of the convention means these dates are no longer valid and some ships can now continue with ballast exchange until 2024.
Under Regulation B-4 (Ballast Water Exchange) of the convention, all ships using ballast water exchange should whenever possible, conduct ballast water exchange at least 200 nautical miles from the nearest land and in water at least 200 metres in depth, taking into account the Guidelines developed by IMO.
In cases where the ship is unable to conduct ballast water exchange as above, then it should be as far from the nearest land as possible, and in all cases at least 50 nautical miles from the nearest land and in water at least 200 metres in depth.
When these requirements cannot be met, areas may be designated where ships can conduct ballast water exchange.
All ships shall remove and dispose of sediments from spaces designated to carry ballast water in accordance with the provisions of the ships’ ballast water management plan (Regulation B-4).
As well as being contained in the convention, ballast water exchange has also been made mandatory under local regulations in many parts of the world as governments saw it as an interim way of tackling the issue of invasive species and disease control.
Reasons why ballast water exchange was considered only a temporary measure include doubts as to its effectiveness in removing all viable organisms from ships’ ballast tanks and also concerns over safety. The latter reason was starkly highlighted in July 2006 when the car carrier Cougar Ace almost capsized following a problem during ballast exchange. Salvage of the vessel was eventually achieved but only after the tragic death of one of the salvage surveyors. Several other less serious incidents have also been reported over time.Regulation D2 Ballast Water Performance Standard
Regulation D2 Ballast Water Performance Standard
This is the standard that all treatment systems have to meet to obtain type-approval under IMO rules. It is also the standard that the US regulations currently require although, the US rules also contain provision for an even stricter future standard.
Ships conducting ballast water management shall discharge less than 10 viable organisms per cubic metre greater than or equal to 50 micrometres in minimum dimension and less than 10 viable organisms per millilitre less than 50 micrometres in minimum dimension and greater than or equal to 10 micrometres in minimum dimension; and discharge of the indicator microbes shall not exceed the specified concentrations.
The indicator microbes, as a human health standard, include, but are not limited to:
- Toxicogenic Vibrio cholerae (O1 and O139) with less than 1 colony forming unit (cfu) per 100ml or less than 1cfu per 1g (wet weight) zooplankton samples;
- Escherichia coli less than 250cfu per 100ml;
- Intestinal Enterococci less than 100cfu per 100ml.
At first sight, the standard seems reasonably clear and concise. However, the use of the word viable with regard to organisms has led to much debate and controversy. This is particularly true with regard to UV treatment systems which operate by destroying cell walls of organisms. This may leave the organism alive but so damaged as to make reproduction impossible.
Some scientists and regulators, especially in the US, have not been convinced that a damaged organism will never be able to reproduce and they have insisted that only dead organisms are safe. In turn this has led to some of the testing methods employed during type-approval being questioned as to their appropriateness.Exemptions available under convention
Exemptions available under convention
Same risk areas
Because the aim of the convention is to prevent species transfer it is clear that for ships which operate only in restricted areas, the need for ballast management does not exist as the same species will be present throughout the area in any case. Regulation A-4 of the BWM Convention recognises this fact and permits any single port state or groupings of port states to permit exemptions.
There are restrictions to this contained within the regulation as detailed below:
- A Party or Parties, in waters under their jurisdiction, may grant exemptions to any requirements to apply regulations B-3 or C-1, in addition to those exemptions contained elsewhere in this Convention, but only when they are:
- granted to a ship or ships on a voyage or voyages between specified ports or locations or to a ship which operates exclusively between specified ports or locations;
- effective for a period of no more than five-years subject to intermediate review;
- granted to ships that do not mix Ballast Water or Sediments other than between the ports or locations specified in paragraph 1.1; and
- granted based on the Guidelines on risk assessment developed by the Organization.
- Exemptions granted pursuant to paragraph 1 shall not be effective until after communication to the Organization and circulation of relevant information to the Parties.
- Any exemptions granted under this regulation shall not impair or damage the environment, human health, property or resources of adjacent or other States. Any State that the Party determines may be adversely affected shall be consulted, with a view to resolving any identified concerns.
- Any exemptions granted under this regulation shall be recorded in the Ballast Water record book.
As at September 2020, no regional exemption arrangements are in place. There are however discussions between some states in the Baltic and also in South East Asia that could result in common risk zones or same risk areas as some call them being established in the very near future.
Discharge to shore facilities
A further possible exemption is available to ships if they discharge ballast water to reception facilities approved under the G5 guideline. This is an option that has been promoted by numerous parties and there are projects being developed in India and the Netherlands involving treatment systems installed in barges or ballast boats or even containerised systems placed on shore at terminals.
Two other options have been proposed as ways of avoiding installing ballast treatment systems on board. The first of these is one that has long fascinated naval architects and that is the no ballast onboard design. While theoretically possible, the uses to which ballast is put with regard to correcting lists or poor trim – sometimes in emergency situations – or altering draught for operational reasons make such a concept improbable for most ship types.
The second alternative is to use treated freshwater from municipal systems instead of water taken from the local environment. Again this is not impossible but there are objections on several grounds. Expense is high on the list as potable water is normally quite costly. Another objection is that in many countries clean fresh water is in short supply and use for ballasting could not be justified. Finally, water standards vary around the world and in some instances, water from municipal supplies would not meet the standards applicable in some ports where the water would be discharged.IMO Type-approval process (G8)
IMO Type-approval process (G8)
The long delay in implementing the convention was wholly a result of it not having been ratified by sufficient states to meet the tonnage target rather than insufficient treatment systems having become commercially available. However, the delay was useful in that certain problems have been identified with some approved systems and technologies and that led to calls for a tightening up of the whole approval process which has now been achieved.
To become type approved, systems have to undergo a series of shore-based tests followed by a further testing period onboard a ship under normal operational conditions. In addition, systems that use an ‘active substance’ as part of the treatment process must also have that substance approved by the IMO.
Full details of the procedures for testing and performance standards are laid out in IMO guidelines to the Convention. The process for systems not making use of an active substance is set out in G8 and for those that do, the relevant process is G9. These terms will frequently be met when looking through system literature from manufacturers.
It is fair to say that some systems that have been given type approval have experienced some difficulties when installed on ships operating in different regions or circumstances to those prevailing when the system underwent onboard testing.
Evolving to the BWMS Code
At MEPC 67 in September 2014, the IMO developed a plan of action to conduct a comprehensive review of G8 taking into consideration the associated guidance documents (MEPC.228(65), BWM.2/Circ.28, BWM.2/Circ.33, and BWM.2/Circ.43).
The review addressed differences in type approval protocols of member States, issues raised by, and additional data that became available from, the Study on Implementing D2, and industry concerns outlined in the annex to MEPC 67/2/6 (ICS et al.). Those concerns included testing using fresh, brackish and marine waters with a temperature range from cold to tropical warm; testing water with organisms that challenge the treatment process (eg. low natural mortality or high resistance to disturbance) and with suspended solids; including results of failed tests in the averaged result; and using realistic flow rates. MEPC67 also accepted the principle of grandfathering by agreeing that ships fitted with existing G8 approved systems should not be penalised.
A revised version of the G8 guidelines as MEPC.279(70), was presented in October 2016 at MEPC 70 and the same meeting also agreed to continue revision. Since changes have been introduced into the type approval process, the status of systems approved under earlier rules has been questioned. At MEPC 70, the IMO recommended application of the revised Guidelines as soon as possible and agreed that BWMS installed on ships on or after 28 October 2020 should be approved taking into account the revised guidelines. Systems installed prior to that date could be approved using the existing guidelines or the revised guidelines.
Under the 2016 version of the Guidelines, the type approval process contains detailed requirements for land-based, shipboard, and other tests set out in an annex. A ballast water management system which in every respect fulfils the requirements of the Guidelines may be approved by flag states for fitting on board ships. The approval should take the form of a Type Approval Certificate for BWMS, specifying the main particulars of the system and any limiting operating conditions.
It was also agreed that the approval process should be made mandatory and the MEPC instructed the IMO Secretariat to prepare the Code for approval of ballast water management systems as well as draft amendments to the BWM Convention making the Code mandatory, for circulation with a view to adoption following entry into force of the Convention.
MEPC 72, in April 2018 duly adopted the new Code as well as amendments to the BWM Convention which mandate that systems be approved under this new BWMS Code. There is nothing completely new in the code which is still technically consistent with the 2016 G8 guidelines adopted by resolution MEPC.279(70), but it sets a mandatory cut-off date after which ballast treatment systems approved under earlier G8 processes cannot be installed on ships.
The code defines that systems should be approved in accordance with:
- the revised G8 Guidelines (as per MEPC.279(70)) are deemed to be in accordance with the code; and
- the earlier versions of the G8 Guidelines (MEPC.125 (53) and MEPC.174(58)) as of 28 October 2018, may continue to be installed* on board ships only until 28 October 2020.
*Through a new Unified Interpretation, ‘installed’ means the contractual date of delivery of the system to the ship or, in the absence of such a date, the actual date of delivery of the system to the ship
The latest G8 is more prescriptive with respect to some details and requires harmonisation between administrations to assure that administrations are validating limitations the same way. Systems that can be scaled to suit different ship types must now be tested using the system size considered by the maker to be the most vulnerable to scaling. The control and monitoring system has received more focus.
Documentation requirements now include detailed functional description and a software change handling log. The changes also mean that systems presented for testing should be commercially ready systems and not prototypes. Testing must also be carried out over a wider range of environmental parameters and the potential for regrowth needs to be determined.
Some have said that the new rules will mean that IMO type approval testing is now more rigorous than the USCG process. In addition the shipboard testing requirements and tank holding times may be difficult to achieve during normal operation of the ship as regard both environmental parameters and voyage length.
A new requirement of the guideline that will apply to many systems is that management of hazardous gases produced by or used in treatment systems now needs to be included. This covers monitoring that ensures redundancy and independent shutdown following a failure. The environmental testing to be conducted on the treatment systems electric and electronic components shall now follow testing defined by IACS UR E10, Rev.6, October 2014 instead of an IMO G8 unique test programme.
Guideline changes adopted at MEPC 70 now in BWMS Code
- Testing Facilities – Testing is to be carried out by an independent facility accepted by the Administration. Facilities should implement a rigorous quality control/quality assurance program that addresses appropriate challenge water, sample collection, sample analysis and method detection limits.
- Salinity and Temperature – Testing is to be carried out across a full range of salinities (fresh, brackish and marine) and through a temperature range of 0°C to 40°C (2°C to 40°C for fresh waters).systems unable to demonstrate successful performance across these salinity and/or temperature ranges will be assigned Limiting Operating Conditions on the Type Approval Certificate.
- Consecutive Testing – Land-based testing is to consist of five consecutive valid test cycles that show D-2 compliance. Shipboard testing is to reflect actual ballast operations and consist of at least three consecutive valid tests, which show D-2 compliance spanning a period of not less than six months.
- System Design Limitations – An important development is the concept of documenting the critical parameters known as System Design Limitations (SDL). These parameters impact the operation of systems (e.g., minimum and maximum flow rates, time between ballast uptake and discharge) and design limits (e.g., water quality expressed by oxidant demand and ultraviolet transmittance).
- SDLs are to be identified by the manufacturer, validated during testing and indicated on the Type Approval Certificate.
- Bypass Arrangements – systems bypass or override arrangements, provided to protect the safety of the ship and personnel in the event of an emergency, should activate an alarm and be recorded by the control equipment.
- Self-monitoring – systems are to be provided with a system that monitors, records and stores sufficient data/parameters to verify correct operation for the past 24 months. Alerts are to indicate when the system is shutdown or when an operational parameter exceeds the approved specification.
- Scaling Effects – Mathematical modelling and/or calculations should demonstrate that any scaling of the systems will not affect the functioning and effectiveness on board the ship. Shipboard testing is intended to further validate the scaling and should, preferably, be carried out at the upper limit of the rated capacity of the systems.
- Report of Test Results – Reports for land-based and shipboard testing, submitted to the Administration, should include information regarding the test design, methods of analysis and the results of these analyses for each test cycle, including invalid test cycles, system maintenance logs and any observed effects of the system on the ballast system. Shipboard test reports should include information on the total and continuous operating time of the system.
- Installation Survey and Commissioning Procedures – Prior to issuance of the International Ballast Water Management Certificate, installation of the system is to be carried out in accordance with the technical installation specification, relevant Type Approval Certificate, and the manufacturer’s equipment specification. The workmanship of the installed system, including completion of all agreed commissioning procedures is to be satisfactorily demonstrated.
As with most regulation, the core elements are supplemented by further requirements and the Ballast water Convention is no different in this regard.
There are further requirements for shipowners, port states and flag states. For shipowners this entails drawing up a ship-specific ballast water management plan for vessels engaged in international trade and all ships subject to the convention will also have to carry a Ballast Water Record Book and an international ballast water management certificate.
Many of the systems developed to treat ballast water make use of electronic logging of ballast water operations and the data recorded will in many cases be used as either the basis for the entries in the record book or as a substitute for it. The exact requirements will be determined by flag states. Under Article 5 of the convention, signatory states undertake to ensure that ports and terminals where cleaning or repair of ballast tanks occurs, have adequate reception facilities for the reception of sediments.
There is no mention of who is responsible for the cost of such facilities but if similar arrangements apply as for oil waste and garbage then it is likely that the charges will fall upon the shipowner whenever they are used.
Under Article 13 Parties undertake, directly or through the IMO and other international bodies, as appropriate, to aid other Parties with technical assistance, co-operation and regional co-operation. This should not affect shipowners but may find resistance from system suppliers who have expended vast sums on research and development and obtaining patents for some aspects of their systems.Additional Type-approval processes for systems using active substances (G9)
Additional Type-approval processes for systems using active substances (G9)
The G8 type-approval process must be followed by any system seeking IMO type-approval regardless of treatment methodology. However, for systems that employ an ‘active substance’ an additional stage is also required.
An active substance is defined by the IMO as ‘a substance or organism, including a virus or a fungus, that has a general or specific action (chemical or biological) on or against harmful aquatic organisms and pathogens’.
In practice most of the systems employing active substances use a chemical containing chlorine which is added to the ballast stream on uptake or make use of electrochlorination where the active substance is generated from the ballast water itself by means of electrical treatment.
Approving an active substance is a two-step process with Basic Approval followed by Final Approval. The Basic Approval is based upon data supplied by the manufacturer to the IMO following laboratory testing. Final Approval requires the substance to be tested under full-scale operation on the system test bed. What constitutes an active substance has been the subject of much debate. In the early days of system development, some systems that made use of Ultra Violet (UV) irradiation of the ballast water were considered to be making use of an active substance as the UV process produces short-lived hydroxyl radicals in the ballast water. Later, following some challenges to individual governments, this was changed. As a result, some systems employing UV have active substance approval and others do not.