USCG flags ballast water management breaches

06 Jul 2017

The US Coast Guard (USCG) has reacted to ‘a number of reports’ of vessels discharging untreated ballast water, reminding operators that sequential exchange affords compliance only under IMO rules.

An investigation into the incidents, which occurred on vessels beyond their compliance date for USCG rules and without a valid extension, found that the sequential exchange method allowed under regulation D-1 of the IMO’s Ballast Water Management (BWM) Convention had been misinterpreted as applying to the US regulations.

In a post on the US Maritime Commons blog today, the USCG noted: “These Statements of Compliance [allowing sequential exchange] are issued under the provisions of the BWM Convention, which the US is not signatory to. Under the US ballast water regulations, meeting the BWM Convention requirements for sequential exchange is not an acceptable method for vessels beyond the compliance date without a valid extension.”

Vessels beyond their compliance date can use several BWM methods when operating in US water, including a US type approved BWM system or alternate management system; ballast water taken only from the US public water system ; discharge to an external treatment facility; or refraining from discharging within 12 nautical miles of the US coast.

Sequential exchange is a process whereby ballast tanks are emptied until the ballast pumps lose suction. Tanks are then further stripped by eductors before fresh ballast is taken in.