Coldharbour Marine’s In-Tank Ballast Water Treatment wins USCG AMS  approval



Coldharbour Marine’s Ballast Water Management System (BWMS) has secured Alternate Management System (AMS) approval under the scheme operated by the US Coast Guard.

Coldharbour has adopted an innovative ‘in tank-in voyage’ approach to ballast water treatment- particularly relevant to the needs of Large Tanker, LNG Carrier and Large Crude Carriers which move thousands of tons of ballast water.  


USCG regulations require all ships calling at US ports and planning to discharge ballast water to carry out ballast water exchange or treatment in addition to sediment management. Ballast water exchange will only be an option for a limited period, following which ships discharging into US waters will be required to install a treatment system.. The AMS avoids penalising ships that have already fitted a treatment system approved by another flag administration.

A ship with an AMS approved system installed can use it for a period of five years beyond the date when the ship would otherwise be required to comply with the USCG discharge standard.  For a list of AMS approved systems see US Department of Homeland Security’s website

Coldharbour’s BWMS has no filtration, requires no connection to ballast pumps or lines and is immune to pump flow rates, pressure losses or power shortages: guaranteeing zero disruption during cargo and ballast operations- including gravity ballasting and deballasting.

Water temperature and quality (suspended solids) have no impact on performance and, by operating during the voyage, crews are free for port duties/essential maintenance. With a small physical footprint and no requirement for modifications or connections in the pump room the BWMS equipment can be installed almost anywhere, while the Inert Gas Generator at the heart of the system can double up to provide inert gases for cargo blanketing. 

Based upon established marine technology with very low maintenance costs, the Coldharbour BWMS requires minimal crew training to operate and maintain.  A further advantage is that by treating ballast water during the voyage, the risk of regrowth is eliminated even on the longest ballast voyages.


Earlier this year Coldharbour secured UK MCA type approval under the watchful eye of Lloyds Register, who independently audited the land and sea tests.   Andrew Marshal, Chief Executive of Coldharbour Marine, said, “The MCA is recognized in the US as a tough accrediting body so it took Coldharbour only 4 months since gaining initial accreditation to win AMS approval.  We will now move to full USCG type approval and have signed up to that program already. “ 









our news