In December 2024, the Finnish Parliament banned the discharge of wastewaters from cargo ships into the Baltic Sea in Finnish territorial waters. The bans on ship discharges will come into force gradually from 1 July 2025. First, a ban on discharges of sewage and open-circuit scrubber wastewater will come into force, a non-profit organization Baltic Sea Action Group (BSAG) said.
The Baltic Sea is one of the busiest sea areas in the world. However, the Baltic Sea’s specific characteristics, such as shallowness, low water turnover and enclosed nature, make it vulnerable to eutrophication and pollution. A study published by BSAG in June shows that sewage discharges are polluting the Baltic Sea, underlining the importance of limiting discharges in this fragile ecosystem. Most wastewaters from cargo ships still end up in the sea, although voluntary measures have been promoted, including through international cooperation within Baltic Marine Environment Protection Commission HELCOM.
Until now, cargo ships have been allowed to discharge their wastewater into the Baltic Sea with relatively few restrictions. Cargo ships have been allowed to discharge untreated sewage 22 kilometres from the nearest shore and treated sewage up to 5 kilometres from the nearest shore. Treatment on cargo ships removes bacteria from the wastewater but is inefficient in removing nutrients that cause eutrophication of the Baltic Sea. There have been no restrictions on discharges of grey water, such as shower and washing water.
From 1 July 2025, no more sewage or wastewater from open-circuit scrubbers may be discharged into the sea in Finnish territorial waters. Sulphur scrubbers are devices used by ships to reduce sulphur emissions from exhaust gases by injecting water into the exhaust gases. The scrubbing water produced by exhaust gas cleaning contains substances harmful to marine life, such as metals and organic compounds. Closed-loop sulphur scrubbers collect the harmful substances separately and purify the water. The discharge of these wastewaters into the sea will be banned from 1 January 2029. The discharge of grey water into the sea will be banned from the beginning of 2030.
BSAG calls for a Baltic Sea-wide ban on wastewater discharge. Sweden will ban discharges from scrubbers on 1 July 2025. A similar ban is also planned in Denmark. Finland becomes leader in reducing wastewater discharges from ships by introducing a more comprehensive ban.