Study focussed on port water quality. Image credit: Ship & Bunker.
Washwater from open loop scrubbers has a minimal effect of seawater quality in port, a new study has found.
The research, undertaken by C E Delft and commissioned by Cruise Lines International Association Europe, Interferry and European Community Shipowners' Associations, focussed on washwater accumulation in port waters in Europe.
Under the terms of the study, the preliminary conclusions were that "using open-loop exhaust gas cleaning systems (EGCS) increase the equilibrium concentration in the port by 0% - 0.01% of the annual average environmental quality standard in the European Union in 2021".
For four compounds, "naphthalene, nickel, benzo(a)pyrene, and fluoranthene, open-loop EGCSs increase the equilibrium concentration in the port by 0.02% - 0.2%" for the same standard.
The limit value is set by the annual average environmental quality standard in the EU in 2021.
The report will inform International Maritime Organisation thinking on scrubber pollution and will be presented to the next pollution prevent and response sub-committee (PPR7) meeting which is reviewing the 2015 guidelines for EGCS operation.
Scrubber equipment allows a ship to continue to use high sulfur fuel oil as the sulfur is removed by a washing process. The washwater can either be discharged into the sea or held onboard ship for discharge to port facilities.