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An installed ‘Alternate Management System’ (AMS) for treatment of ballast discharged in US waters may be used for five years from any extended compliance date rather than from its installed date.


In accordance with US regulations on ballast water discharge standards, and in light of the fact that there are currently no US Coast Guard type-approved ballast water treatment systems, a vessel discharging ballast into US waters after the vessel’s original compliance date[i] must either have obtained the water from a US public water supply; or treat the water onboard by the use of an ‘Alternate Management System’ (AMS).[ii] See also Gard Alert of 27 March 2012.


Vessel owners and operators can also apply to the Coast Guard for an extended compliance date if they can document that, despite all efforts, the vessel is not able to comply with the ballast water management requirements. In November 2015, the Coast Guard published CG-OES Policy Letter 13-01, which provides guidance to vessel owners and operators seeking to extend compliance dates for implementing ballast water management methods. See also Gard Alert of 3 November 2015.


However, since regulations permit the use of an AMS for no longer than five years from the date they would otherwise be required to comply, and Policy Letter 13-01 do not specify to which compliance date category the AMS provision apply, many vessel owners and operators have been left wondering if their installed AMS could be used for five years from their original compliance date, from the AMS installed date or from their extended compliance date. In their Marine Safety Information (MSIB) No. 010/16 dated 16 August 2016, the Coast Guard therefore makes clear that:

  • A vessel with an installed AMS may request an extension and operate under the terms of that extension rather than using the AMS, or it may employ other BWM methods available under the regulation.
  • A vessels operating under an extension to its compliance date may install an AMS and choose not to use it during the period of extension.
  • If an AMS is installed prior to the expiry of a vessel’s extended compliance date, the vessel may use the AMS for no longer than five years beyond the vessel’s extended compliance date.


The MSIB also shed light on other aspects concerning the use of AMS, e.g. what happens if the foreign type approval expires after installation; what are the reporting requirements if an AMS is not operating properly; etc.



Members and clients with vessels using, or planning to use, an AMS while operating in US waters, are advised to take note of the clarifications provided in MSIB No. 010/16. Such vessels should also carry onboard a copy of the AMS acceptance letter issued by the Coast Guard to the ballast water management system manufacturer and make this available for review when operating in US waters.

Information and documents relating to the US Coast Guard ballast water management program can be found HERE. Information on regulatory updates are also provided via the blog Coast Guard Maritime Commons. For those still in the process of planning the installation of a ballast water treatment, key elements of the preparatory work is highlighted in our Gard Alert “Prepare to manage ballast water” of 20 June 2016.

[i] Each vessel’s original compliance date is determined by its ballast water capacity and its next scheduled dry docking as per the implementation schedule provided in 33 CFR 151.2035.


[ii] An AMS is a ballast water treatment system approved by a foreign administration pursuant to the standard set out in the IMO Ballast Water Management Convention and in accordance with 33 CFR 151.2026.