Sweden. City of Stockholm

Date of agreement:31 Aug 2017
Customer:City of Stockholm
Amount in SEK:SEK 1,500 million
Amount in EUR:EUR 158.17 million
Maturity:10 years
NACE sector / loan type:Sewage and refuse disposal, sanitation and similar activities

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

Financing from NIB Environmental Bond proceeds

NEB-eligible share: 100%

NEB category: Water management and protection

Amount disbursed: EUR 157.2 million

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


The loan has been provided for an expansion of the Henriksdal underground wastewater treatment plant and to construct a 15-kilometre sewer tunnel under the southern-central part of Stockholm, Sweden. Due to an increase in scope and investment size, this loan is the second to be provided by NIB to the same project. The first, a SEK 3 billion loan, was approved in 2016.

The City of Stockholm has decided to double the capacity at Henriksdal to more than 500,000 cubic metres per day and close its wastewater treatment facility at Bromma. The wastewater currently collected at Bromma will be transported by gravity to Henriksdal through the new tunnel at depths of between 23 and 55 metres.

Stockholm is the capital of Sweden and the most populous city in the Nordic–Baltic region, with 923,516 residents at year-end 2015. The city is one of the fastest-growing regions in Europe and benefits from a strong economy and a rapidly growing population.

Fulfilment of NIB's mandate


The extension of wastewater services will increase the flexibility to gradually accommodate higher wastewater loads from a growing region. While the quality of wastewater treatment is generally high in Stockholm, investments are needed to accommodate population growth and the increasing frequency of heavy rain. The increased quality of the wastewater treatment is expected to have a positive impact on the productivity of public sector services.


The increased transport capacity of the sewer network is expected to reduce the overflow of untreated wastewater into Lake Mälaren from an estimated 185,000 cubic metres annually to less than 10,000.

The new MBR technology will result in 40% lower discharges of phosphorus and 33% lower discharges of nitrogen into the Baltic Sea. It will also remove all particles larger than 0.04 micrometres, i.e. all microplastics, from the wastewater.

Sustainability summary

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

The major potential for negative environmental impact relates to noise during the construction phase of the tunnel. No risk of any negative impact on groundwater quality is foreseen. Leftover materials from the tunnel construction will be used at building sites in the Stockholm area.

The city will change its sludge treatment technology, and the production of biogas will almost double to 35 million normal cubic metres a year from the current 18.2 million. The increase is largely due to the treatment of external organic waste in the form of food waste and fats from fat separators.

Press release

NIB signs loan agreement for Stockholm wastewater treatment

Press release

NIB tecknar avtal om lån för avloppsrening i Stockholm