- Study says open-loop scrubber discharge does not breach guidelines.
- Increase in traceable pollutants from open-loop scrubbers in port water and sediments shown but levels are far below the established guidelines.
- CE Delft presented the paper to IMO during PPR 7 in February 2020 and also to delegates at the 2020 Clean Shipping Alliance in London.
A study by CE Delft shows that the level of traceable pollutants from open-loop scrubbers in port water and sediments are far below the established guidelines, writes Craig Jallal for an article published in Riviera Maritime Media.
Discharge does not breach guidelines
CE Delft is an independent research and consultancy organisation specialising in developing innovative solutions to environmental problems.
A recent study by CE Delft shows there are increases in traceable pollutants from open-loop scrubbers in port water and sediments. But also shows that the levels are far below the established guidelines.
Study – Impact of discharge
The study carried out by CE Delft was “The impacts of EGCS washwater discharges on port water and sediment”.
CE Delft and another research establishment, Deltares, worked together to model the impact of exhaust gas cleaning systems (EGCS or scrubbers) on port water and sediment.
Study calculation
- The study calculated the predicted equilibrium concentrations for 11 metals and 16 polycyclic aromatic hydrocarbons (PAHs) and
- compared this with the EU Water Framework Directive.
Study findings
- The study found the increase in concentrations caused by continuous discharge of a relatively high amount of EGCS washwater is less than 0.1% of the limit value in the EU WFD for 2021 for these priority substances.
- In ports located in zones with small tidal ranges, such as the Baltic Sea, the increase in concentration can amount to 0.6% of the limit value for a few PAHs.
EU WFD guidelines
To put this into context, the findings would have needed results of 100% or higher to breach the EU WFD guidelines.
The study was commissioned by the Cruise Lines International Association Europe (CLIA Europe) following concerns raised about the environmental impact of open-loop scrubber wash wastewater in ports, and the banning by some authorities of their operation in some ports.
Paper presented to IMO
CE Delft presented the paper to IMO during PPR 7 in February 2020. CE Delft senior researcher and consultant Dagmar Nelissen presented the paper to delegates at the 2020 Clean Shipping Alliance in London.
Ports too quick in ban decision
The results of the paper seem to indicate that ports were too quick to ban open-loop scrubbers without scientific evidence but mainly based on pressure from the general public.
This points to the ongoing conflict as shipping strives to meet IMO greenhouse gas emissions goals.
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Source: Riviera Maritime Media
