Despite the IMO’s approval for scrubbers as a safe bet for the new sulphur regulations, some local authorities of coastal countries are concerned about the wash water discharged from these scrubbers, reports the Gard.

To counter this they have come up with further local regulations. This is an insight on how to manoeuvre through these local restrictions. We already reported on this in January and February. The table below has the latest update.

What does IMO say?

IMO considers exhaust gas scrubbers to be an acceptable means of reducing vessels’ sulphur emissions and ensuring compliance with MARPOL Annex VI.  A separate guideline, Resolution MEPC.259(68), specifies the requirements for verification, testing, survey, and certification of scrubber systems and sets out the criteria for discharging scrubber wash water into the sea.

Local restrictions requiring continuous updates

However, some coastal states and ports have implemented local regulations with more stringent requirements that restrict or completely prohibit the discharge of wash water from open loop scrubbers or prohibit the use of scrubbers. We are currently aware of the following regions/states/ports with local regulations that have an effect on the discharge of exhaust gas scrubber wash water, although the list should not be considered as complete.  Read even more here.






Belgian federal law: discharge only allowed in coastal and open seawaters when at least 3nm off coast. Discharges must not imperil EU Water Framework Directive objectives 2016.
Flemish regional law 26/3/1976: discharge not allowed in ports or inland waters.


Inland emission control areas, ), port water areas of coastal domestic ECAs and Bohai Bay waters

China’s Ministry of Transport (MOT) issued its ‘Notice on Regulating the Implementation of Supervision and Management of Ship Air Pollutant Emission Control Areas’ which states that from 1 January 2019 discharge of wash water from scrubbers is prohibited in China’s inland emission control areas (ECAs), port water areas of coastal domestic ECAs and Bohai Bay waters.

The document also states that a ban in the entire coastal domestic ECA will be announced in due course. Our local correspondent, Huatai, has published a useful circular on China’s ban on scrubber wash water discharge, which can be accessed here.


Inland Waterways, the Rhine, canals and ports within inland waterways

Discharge not allowed pursuant to Articles 1 and 3 of the CDNI Convention.

See: Convention on the Collection, Deposit and Reception of Waste Produced during Navigation on the Rhine and Inland Waterways (CDNI)


Dublin port

See: Port of Dublin’s Notice to Mariners No. 37 of 2018 Prohibition on the Discharge of Exhaust Gas Scrubber Wash Water stipulates that discharge of wash water is prohibited in waters under Dublin port jurisdiction. Dublin port jurisdiction includes waters from the Matt Talbot Memorial Bridge eastwards to a line from the Baily Lighthouse through the North and South Burford buoys and through Sorrento Point.
See: http://www.dublinport.ie/wp-content/uploads/2018/06/37-2018-Prohibition-on-the-Discharge-of-Exhaust-Gas-Scrubber-Wash-Water.pdf

As per Port of Waterford’s marine notice ‘Prohibition on the Discharge of Exhaust Gas Scrubber Wash Water’, discharge of scrubber wash water is prohibited in port as from January 2019.


Unclear, some ports

In DG Engineering Circular 05 of 2018, India seems to indicate that scrubber wash water discharges are allowed if the criteria set out in MEPC.259(68) are met. However, this is qualified with a requirement that local regulations should also be followed. As of now, it is not clear if local restrictions will be imposed in some areas.


All ports

General position, as mentioned in European Commission Report (2016): discharge is not allowed in territorial and port waters. Discussions are currently ongoing within the European Commission, on improving the regulations and to provide more clarity.


All ports

Current position, as mentioned in European Commission Report (2016): discharge is not allowed in port waters, according to port rules and conditions of use approved by the Ministry of Transport.

Lithuanian authorities are studying the impact of scrubber  wash water discharges on the marine environment. When results will be clear, conclusions will be provided.


Heritage fjords

The Norwegian Maritime Directorate (NMD)  proposed a ban on use of scrubbers in Norway’s heritage fjords. The proposed ban extends to all types of scrubbers including closed loop and hybrid systems.

Norway is also proposing a prohibition of incineration of waste on board vessels in the world heritage fjords. Implementation is expected during first half of 2019.


Singapore port

Ban on the use of open loop scrubbers expected to take effect on 1/1/2020, according to the Maritime and Port Authority of Singapore (MPA),  

MPA has published useful guidance on IMO’s 2020 Sulphur limits. The document advises ships fitted with open loop scrubbers to ‘carry out the switch to either closed-loop mode or to compliant fuel well in advance of the vessel’s arrival at the port waters’.

United Arab Emirates

Abu Dhabi and Fujairah ports

Abu Dhabi Ports Company Policy: In 2013 Abu Dhabi authorities issued ‘Vessel Discharge and Maintenance Guidelines For Owners, Masters And Agents’. It states that scrubber wash water can be discharged in port waters if free from pollutants while scrubber sludge should be discharged from the vessel to an Abu Dhabi Ports Company (ADPC) licensed waste disposal contractor.

Fujairah: As per notice to mariners no. 252, Harbour Master of Fujairah has announced that use of open loop scrubbers will be banned in port waters.

United States

Californian ports and waters

The CARB OGV (California Air Resource Board for Ocean Going Vessels) regulations do not permit the use of abatement technologies such as scrubbers, hence their use as well as any discharge of wash water is prohibited. However, pursuant to CARB’s Marine Notice 2017-1 discharge is permitted if the vessel has an experimental or temporary research permit.

United States

Connecticut ports and waters

Connecticut has laid down specific conditions as part of the 2013 Vessel General Permit (VGP) requirements.

In accordance with section 6.5.9[UK1]  of the 2013 VGP, discharge of exhaust gas scrubber washwater into Connecticut waters from any vessel covered under the VGP is prohibited. Please see CGS section 22a-427, and Connecticut Water Quality Standards (CT WQS).

United States


Conditional section 401 WQC (Water Quality Certification) as mentioned in section 6.7 of 2013 VGP allows for discharge of wash water subject to certain requirements being fulfilled. These requirements can be found in the same section.

Various other coastal states and ports are discussing enforcing similar bans citing the adverse effects of scrubber wash water on the marine environment. It is therefore likely that the above list of states/ports which currently regulate open loop scrubber discharges in their waters will grow over time.

How to plan the change?

As things are continuously changing, monitoring the situation closely is imperative.

Ensure that crews onboard vessels fitted with open loop scrubbers are made aware of any relevant local discharge requirements in force. As a precautionary measure, it is advised that vessels with open loop scrubbers installed, approach the local agents for detailed up to date requirements on the discharge of scrubber wash water as part of a vessel’s voyage planning.

In areas where the discharge of wash water is not permitted, vessel operators have two options to choose from to ensure compliance with the sulphur limits:

  1. use compliant fuel instead of open loop scrubbers;
  2. switch to closed loop mode of operation, in which case it will be necessary to convert currently installed open loop systems to closed loop or hybrid systems, if not already done.

Any changeover should be carried out well in advance of the vessel entering the areas with prohibition or restrictions in place. This will help in identifying operational issues, if any, after the changeover, and will allow for sufficient time to rectify such before the vessel enters the area.

Source: Gard

Potential impact of scrubber wash water on the marine environment

The table below shows the potential impact of scrubber wash water on the marine environment. Next to the low pH that will contribute to further acidification of the oceans and algae growth, heavy metals and arsenic are, among other pollutants, discharged into the sea.
A recent study from M. Koski, Stedman and Trapp from 2017 “Ecological effects of scrubber water discharge on coastal plankton: potential synergistic effects of contaminants reduce survival and feeding of the copepod Acartia tonsa” comes to the same conclusion.

Contents of sulphur, metals and organic hazardous substances in sea water (open loop) and centrifuged fresh water (closed loop) wash water from scrubbers (effluent of ficaria seaways) compared to current EU or Danish Environmental Quality Standards (EU EQS/ Danish EQS) for the marine environment.

Source: Assessment of possible impacts of scrubber water discharges on the marine environment. Danish Ministry of Environment (EPA), 2012 p 65 - By Mfame editor, February 6, 2019.


Euroshore comments

Analysis of effluent of open loop scrubbers not equipped with after treatment (before the discharge into the sea,) shows that the effluent has a low pH.  It also contains amounts of heavy metals and arsenic exceeding the environmental quality standards in the EU and Denmark. This means that the impact on shallow waters may not be underestimated, especially when the technology will be picked up by more seagoing vessels.

A ban for open loop scrubbers in these waters is recommended.

More comments in Euroshore's position paper on exhaust gas cleaning systems.