Sweden: EIB loan to help Stockholm cut wastewater pollution and protect the Baltic Sea

This article is published in association with European Investment Bank.

• The EIB is lending the City of Stockholm €470 million to secure the sewer system of the future
• New technology will reduce nitrogen discharge into the Baltic Sea by 40% and capture microplastics
• Henriksdal will become one of the most modern treatment plants in the world

The European Investment Bank (EIB) is lending the City of Stockholm 5 billion Swedish kronor (around €470 million euro) to finance the city’s largest environmental investment in decades. The project involves closing the Bromma treatment plant and routing all the city’s wastewater to a significantly expanded and modernised treatment plant at Henriksdal.

The key element of the investment is a new wastewater collection tunnel that will transport sewage from Bromma to Henriksdal. The plant there will be expanded using advanced membrane technology, making it possible to treat more water without increasing the floor area and with significantly better results.

Once the upgrade is complete, nitrogen discharge into the Baltic Sea is expected to fall by around 40% and phosphorus discharge by about 35%. The technology also removes microplastics and provides readiness for future treatment requirements, such as the removal of pharmaceutical residues. At the same time, the risk of overflows of untreated wastewater into Lake Mälaren, Stockholm’s source of drinking water, will be reduced.

“This is an investment in a cleaner sea and a more secure water supply”, said EIB Vice-President Karl Nehammer. “By supporting Stockholm’s new treatment solution, we are helping to reduce discharge into the Baltic Sea and strengthen the city’s climate change adaptation measures. The project is fully in line with the EIB’s climate and environmental priorities.”

The total cost of Stockholm’s future wastewater treatment system is SEK 19.5 billion. The EIB’s financing represents around 26% of the investment and is being provided with a long maturity to match the project’s implementation date of 2031.

“We appreciate the EIB’s continued support for the City of Stockholm’s loan financing”, said treasurer at the City of Stockholm Sofie Nilvall. “This time it concerns one of our largest projects, the expansion and modernisation of the Henriksdal wastewater treatment plant, which will strengthen the city in several areas, including the environment, public health and preparedness.”

The project will help Sweden meet its commitments under the Baltic Sea Action Plan and the EU Water Framework Directive and is classified as a climate and environmental investment.

Background information   

EIB Group  

The European Investment Bank (EIB) Group is the financing arm of the European Union, owned by the 27 Member States, and one of the largest multilateral development banks in the world. In 2025, the EIB Group signed €100 billion in new financing and advisory services for over 870 high-impact projects under eight core priorities that support EU policy objectives: climate action and the environment, digitalisation and technological innovation, security and defence, territorial cohesion, agriculture and the bioeconomy, social infrastructure, strong global partnerships and the savings and investments union. Beyond long-term loans for large infrastructure, the EIB Group crowds in private investment for high-risk innovative projects and businesses, with a growing role in Europe’s markets for venture debt, venture capital, guarantees and securitisations.

The EIB is the world’s largest multilateral financier of water projects. In 2025 alone, the Bank provided around €5 billion in financing for water investments, helping improve access to safe drinking water and sanitation for some 32 million people in Europe and beyond.

Through its Water Resilience Programme, the EIB is scaling up support further, with around €15 billion in planned investment between 2025 and 2027. This will help expand and modernise water infrastructure — from flood protection and irrigation to digital water management — while strengthening the competitiveness of Europe’s water sector.

The European Investment Fund (EIF) is the subsidiary of the EIB Group specialised in providing guarantees and equity to improve access to finance for small and medium-sized businesses and startups across Europe. Acting as an anchor investor, through its extensive network of partnering banks and investment funds, the EIF mobilises private investment and nurtures the ecosystem of venture capital funds to support innovative European entrepreneurs.

In 2023, the EIF together with six Member States (France, Germany, Italy, Spain, Belgium and the Netherlands) launched the European Tech Champions Initiative, a fund-of-funds to scale up innovative startups. As of February 2026, this initiative has already enabled the creation of 13 European venture capital mega-funds and scaled up 40 companies, including 11 unicorns (with more than €1 billion in capital).

Photos of the EIB Group’s representatives and headquarters, logo files and video B-roll for media use are available here.