New study finds ‘negligible’ environmental impact from scrubber wash water

A new independent study conducted by Netherlands-based CE Delft has found negligible environmental impact from accumulated scrubber wash water in ports, the Clean Shipping Alliance (CSA) 2020 has highlighted.

Research organisation CE Delft presented its preliminary results to the 74th session of IMO’s Marine Environment Protection Committee (MEPC) last month in London, regarding the impact of open-loop scrubbers on the marine environment and particularly on ports and harbours.

The study indicated that accumulated concentrations of scrubbers wash water components are at very low levels and well below applicable regulatory limits, CSA 2020 shared.

The research, carried out by CE Delft in collaboration with Deltares, an independent institute for applied research in the Netherlands, uses three versions of Deltares’ dynamic computer modelling system MAMPEC. Each version represents a common configuration of European ports, and the study assumes that multiple ships in each modelled port are using open-loop scrubbers around the clock throughout the year.

CSA 2020 executive committee member Poul Woodall, director, environment & sustainability, DFDS, said: “So far, for all parameters considered, the equilibrium concentrations are indicating annualised contributions on the parts per trillion scale, which we understand are actually too small to be detected by existing laboratory equipment. This is an encouraging start.”


CE Delft will continue to assess the accumulated concentration of scrubber discharge water compounds in two more port configurations and compare the resulting concentrations against other standards. It will also compare the compound concentrations being discharged from ships in port with the background concentrations provided to ports by other sources, such as rivers.

CSA 2020 executive committee member Arne Hubregtse, executive board member of Spliethoff Group, observed: “These initial findings are very promising and suggest that those ships operating open-loop EGCS will have near zero impact on the quality of harbour waters.”

Ian Adams, executive director of CSA 2020, added: “While there is no debate surrounding the technology’s air emissions-busting capability, we hope that the CE Delft study, along with other recently published scientific research, will help answer remaining questions surrounding the environmental impact of scrubber wash water.”

Read more: Carnival’s two-year wash-water study affirms scrubbers are positive for environment

Posted 17 June 2019

© Copyright 2019 Seatrade (UBM (UK) Ltd). Replication or redistribution in whole or in part is expressly prohibited without the prior written consent of Seatrade.

Lee Hong Liang

Asia Correspondent

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