Last week, the Finnish Parliament passed legislation banning cargo ships from discharging wastewater in the country's coastal waters.
The new law, set to take effect in July, will make Finland the world's first country to implement such comprehensive wastewater regulations.
Passenger ships have long been prohibited from such practices, but now cargo vessels will also be held to the same standard.
"This is a huge achievement. Major environmental victories are rare, but this decision is truly world-class. No other country has enacted such ambitious laws," said Ville Wahlberg, CEO of the Baltic Sea Action Group (BSAG), an NGO dedicated to preserving the sea's fragile ecosystem.
Mitigation measures
Currently, 20 percent of cargo ships operating in the Baltic offload their sewage at port facilities rather than discharging it at sea. Over the past five years, the volume of shipborne wastewater collected at ports has tripled. According to Vesa Marttinen, Head of Cargo Business at the Port of Helsinki, Finland's infrastructure is well-prepared for this shift.
"We've had facilities in place for years, handling wastewater from passenger ferries and some cargo vessels. Now, we'll work with the remaining ships to ensure they're equipped and their procedures refined," Marttinen explained.
Ship sewage discharged into the Baltic Sea contains large amounts of faecal bacteria and solid waste. Moreover, it is nutrient-rich, exacerbating eutrophication and causing toxic algal blooms in the summer months, such as cyanobacteria.
These discharges, though smaller in scale than pollution from agriculture and forestry, are particularly harmful in the Baltic due to the sea's shallow depth and limited water exchange.
The BSAG has long campaigned against shipborne discharges, initially promoting voluntary measures among shipping companies, ports and waste management providers before advocating for a legislative ban. Wahlberg emphasised the significance of the change.
"There are roughly 2,000 ships on the Baltic Sea daily, with 15 to 20 crew members on each cargo vessel. That's equivalent to a medium-sized town dumping its sewage into the sea. Now, in Finnish waters, this will no longer be possible."
Responsibility now on companies
While the law is a milestone, it does not eliminate all risks. Ships can still legally discharge wastewater in international waters, outside Finland's jurisdiction.
Wahlberg said he believes the responsibility now lies with shipping companies and freight clients to uphold higher standards.
"I trust shipping lines and cargo owners will insist on offloading waste at ports. This law provides a strong foundation, and I'm optimistic we'll see a significant increase in wastewater collected at Finnish ports," he said.
If other Baltic Sea countries were to adopt similar legislation, international waters in the region could also fall under stricter regulations. Collaboration among Baltic ports is already strong, and there is growing interest in Sweden and Denmark to introduce comparable rules for grey water, or water used for washing.
"This law sets a precedent for how such measures can be integrated into national legislation," Wahlberg noted.
"It's a great opportunity to expand this approach to other Baltic countries," he said. "We have a solid example to build on, but achieving widespread adoption will take years."
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