A new report on scrubber washwater, published by the International Council for Clean Transportation, indicates that shipping produces nearly as many tonnes of the effluent in a year as the cargo it carries.
This report is the first global assessment of the mass of washwater discharges expected from ships using scrubbers. The authors used 2019 ship traffic, as a pre-COVID-19 baseline, and considered approximately 3,600 ships that had scrubbers installed by the end of 2020.
Results show that absent additional regulations, ships with scrubbers will emit at least 10 gigatonnes (Gt) of scrubber washwater each year. For context, the entire shipping sector carries about 11 Gt of cargo each year.
Although several governments have taken preventative measures and banned the use of scrubbers in their ports, internal waters, and territorial seas, many have not. Policymakers concerned about the impacts of washwater discharges can consider several actions.
Furthermore, as shown in this report, away from shore, scrubber discharges occur along major shipping routes. Some of these routes pass through PSSAs, including the Great Barrier Reef, where about 32 million tonnes (Mt) of scrubber washwater will be discharged, mainly from ships serving coal terminals in northeast Australia; this represents 5% of the 665 Mt discharged in PSSAs globally.
Container ships, bulk carriers, and oil tankers together account for three-quarters of scrubber installations by number of ships and are responsible for about 70% of scrubber discharges worldwide. Another 15% of discharges are from cruise ships, even though they represent only 4% of the scrubber-equipped fleet by number of ships. Cruise ships are also the main contributor to scrubber discharges in port, and account for 96% or more of discharges in seven of the 10 ports with the highest total washwater discharges.
We expect the results reported in this paper to be representative for the cruise sector if and when the industry returns to normal operations after the pandemic
Credit: ICCT
What is more, ships flying the flags of Panama, Marshall Islands, and Liberia account for about 40% of global scrubber discharges. Several countries have imposed restrictions on scrubber discharges in their national waters but allow ships flying their flag to emit washwater. Panama has banned open-loop scrubber discharges in the Panama Canal and yet registers ships that account for nearly one-fifth of global scrubber washwater discharges.
Credit: ICCT
Considering the above, the report notes that tolicymakers concerned about the impacts of washwater discharges can consider some or all of the actions below.
IMO
The Marine Environment Protection Committee (MEPC) could pass a resolution calling on ships to immediately stop dumping scrubber discharge water in places that should be protected, including estuaries, near-shore areas, marine protected areas, and especially PSSAs. ICCT’s analysis shows that ships with scrubbers are expected to discharge at least 665 Mt per year in PSSAs. These include areas with threatened reef systems, like the Caribbean Sea and the Great Barrier Reef, and areas with endangered marine life, such as the Galapagos Archipelago.
The IMO could ban the use of scrubbers as an equivalent fuel sulfur compliance option for new ships under the International Convention for the Prevention of Pollution from Ships (MARPOL) and establish a timeline for phasing out scrubbers already installed on existing ships. MEPC could also pass a voluntary resolution calling on Administrations (flag states) to not approve the use of scrubbers for ships flying their flag. To be most effective, these provisions should cover both open-loop and closed-loop systems.
Regional/national level
Authorities could prohibit all scrubber discharges in waters under their jurisdiction. If closed-loop scrubbers are used, they should be operated in zero-discharge mode. Waters of the United States, the United Kingdom, and Italy all are expected to receive more than 300 Mt per year of washwater discharges and yet do not currently prohibit the use of scrubbers in their national waters.
Nearby countries could work together to harmonize scrubber discharge restrictions to avoid merely displacing scrubber discharges over political (but not ecological) borders.
Prominent flag states such as Panama, the Marshall Islands, and Liberia, which register ships expected to be responsible for 40% of global scrubber discharges, could agree to phase out the use of scrubbers on ships flying their flags. In the case of Panama, this would mean applying the same discharge bans to ships flying its flag as it does to ships transiting the Panama Canal.
Local level
Ports could proactively ban scrubber discharges in waters under their jurisdiction and require ships to use onshore power when it is available. When not, ports could require that ships use MGO to avoid the need for using heavy fuel oil with scrubbers. Ports with heavy cruise ship traffic could install new or additional shoreside charging facilities.
Ports could conduct ongoing water and sediment monitoring for acids, PAHs, heavy metals, nitrates, and nitrites. Pollutant monitoring could be supplemented with monitoring of photosynthetic activities using available satellite datasets and used as a bioindicator of eutrophication that may be exacerbated by nitrogen pollution from ships.
Credit: ICCT
On the other hand, Clean Shipping Alliance (CSA) says that scrubbers play major role in the smooth transition to IMO 2020.
In fact, the CSA strongly believes that EGCS make a positive difference to the ports and ocean environments in which ships operate and will promote global environmental progress, especially the goal of reducing the health impact from airborne sources, which is at the heart of the IMO 2020 regulation.
There should be broader awareness that EGCS-fitted vessels show a significantly better CO2 performance than similar vessels using refined fuels for compliance, such as MGO/VLSFO. This supports the current ambitions of significantly lowering CO2 emissions by 2030
Poul Woodall, Executive Director of the Clean Shipping Alliance 2020 (CSA), has stated.
Commenting on the findings of the report, CSA states that:
The ICCT report claims that wash water discharges from open-loop scrubbers are ‘hot, polluted and acidic sludge’, which is wrong, and cannot be made by anyone familiar with these systems. We are concerned that this is intentionally misleading
CSA also added that contrary to the report’s comments about washwater constituents, ”laboratory analysis of hundreds of scrubber washwater samples from ships operating all over the world shows that nitrates and nitrites are not normally detected at all, or are at negligible levels.”
As shown repeatedly by recent studies using large data sets of washwater samples laboratory results, the washwater consistently and reliably meets all major international and national water quality standards – including some major drinking water standards
We use technologies like cookies to store and/or access device information. We do this to improve browsing experience and to show (non-) personalized ads. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional
Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.