Sweden. City of Stockholm

Date of agreement:14 May 2024
Customer:City of Stockholm
Amount in SEK:SEK 2 million
Amount in EUR:EUR 172 million
Maturity:10 years
NACE sector / loan type:Sewage and refuse disposal, sanitation and similar activities

This loan contributes to climate change mitigation: 100%

This loan has a positive effect on maritime environments: 100%

Financing from NIB Environmental Bond proceeds

NEB-eligible share: 100%

NEB category: Blue Bond project

Note: For loans in other currencies than EUR, the equivalent in EUR is based on the exchange rate effective for the disbursement. Read more about the NIB Environmental Bonds


NIB is providing the loan to finance part of the City of Stockholm’s investment in the city’s future wastewater project.

The project involves expanding the Henriksdal plant to double its capacity for 1.6 million residents and constructing a 14 kilometre sewer tunnel to redirect wastewater from Bromma, and then close it. The project includes using advanced membrane technology, which may later accommodate pharmaceutical waste treatment. The treated water is released into the Saltsjön bay, significantly reducing phosphorous and nitrogen emissions into the Baltic Sea. The sewer tunnel route allows several emergency sewer overflow points to be connected to the tunnel, significantly reducing the pollution load to Lake Mälaren in periods of extreme rainfall.

Total project cost is estimated to SEK 22.5 billion and project completion is expected in 2031.

Previously, NIB has approved two loans totalling SEK 4.5 billion for the project in 2016 and 2017.

Stockholm is the capital of Sweden and the most populous city in the Nordic–Baltic region, with 988,943 residents at year-end 2023. The city is one of the fastest-growing regions in Europe and benefits from a strong economy and a growing population.

Fulfilment of NIB's mandate

The expected impacts of the investments are unchanged. Stockholm is one of the fastest growing regions in Europe and benefits from a strong economy and rapidly growing population supported by its economic and environmental assets, which are important features of the region’s attractiveness.

The increased sewer capacity will reduce the risk of overflows.

The installation of membrane technology at Henriksdal is expected to significantly reduce environmental impact to the Baltic Sea, achieving a 40% reduction in phosphorus discharges, a 33% reduction in nitrogen discharges. The membrane will also remove all particles larger than 0.04 micrometers, including all microplastics, from the wastewater.

The production of biogas, a renewable fuel, will also increase at Henriksdal.

Sustainability summary

This is a project with a potentially extensive environmental impact (category A, read more)

The major potential for negative environmental impact occurs during the construction phase and relates mostly to noise. There is no foreseen risk of negative impact on ground water quality. Leftover materials from the tunnel construction will be used at building sites in the Stockholm area.

Press release

NIB finances Stockholm’s Future Wastewater Treatment project

Press release

NIB finansierar Stockholms framtida avloppsvattenprojekt