Singapore’s Maritime Port Authority (MPA) will ban the discharge of wash water associated with the wet, open-loop configuration of exhaust gas cleaning systems.
MPA chief executive Andrew Tan announced the ban, which reportedly will become effective from the onset of the IMO-mandated global cap on sulphur in fuel on 1 January 2020.
“To protect the marine environment and ensure the port waters are clean, the discharge of wash water from open-loop exhaust gas scrubbers in Singapore port waters will be prohibited,” Mr Tan said in a speech to the Singapore Registry of Ships forum.
Vessels fitted with open-loop scrubbers will be required to use compliant fuels in Singapore port waters. Ships fitted with hybrid scrubbers will be required to switch to the closed-loop mode of operation, he said.
Scrubber manufacturers have reported that a majority of shipowners have opted to install open-loop systems on their vessels.
Mr Tan also said “Singapore, as a party to Marpol Annex VI, will be providing reception facilities for the collection of residues generated from the operation of scrubbers”.
Studies, including from the European Union’s Joint Research Centre (JRC), have found the 'residues' in exhaust gas wash water lead to ocean acidification.
JRC researchers looked at the effect the wash water released by ships in the North Sea has on the acidification of sea water and compared it with the impact of CO2 emissions on ocean acidification.
The study found that “along major shipping lanes, sulphur dioxide (SO2) emissions from ships can further ocean acidification with a rate that is two-fold with respect to that caused by carbon dioxide (CO2) emissions”.
The study also found that increased SO2 levels decrease the ocean’s ability to absorb CO2 and “indicated potential problems with water quality in critical areas such as ports, estuaries and coastal waters”.
Citing different studies, scrubber advocacy organisation Exhaust Gas Cleaning Systems Association (EGCSA) has called the addition of SO2 from scrubber wash water “insignificant when compared with the quantity already in the oceans”.
Describing chemical reactions involved, EGCSA also said the sea water used to wash exhaust in open-loop scrubber configurations "buffers or neutralises acids created by scrubbing".
EGCSA Director Don Gregory was dismayed at the news from Singapore's MPA. He told this publication "It is disappointing that after nearly 25 years of debate and development of regulations at IMO, the Singapore MPA as a signatory to MARPOL Annex VI has not voiced or submitted its concerns to the IMO."
"We recognise a sovereign state is free to determine its own rules in its territorial waters, but industry could reasonably expect the MPA to seek dialogue with stakeholders before making such a unilateral decision and announcement. EGCSA will seek to have a dialogue with the MPA to understand the facts behind the concerns which have led to this dramatic announcement," he said. To read the EGCSA response in full, click here.
Singapore is one of the world’s busiest ports and is a major bunkering station for refuelling the shipping industry.
In his speech, Mr Tan also sought to allay fears that 2020 sulphur cap compliant fuels would not be readily available.
“As a major bunkering hub, we are working closely with our bunker suppliers to ensure that there will be an adequate supply of compliant fuel oil in Singapore well in advance of 2020. We will produce a list of suppliers that are able to supply compliant fuel by the middle of next year,” he said.