Sweden. Käppalaförbundet

Date of agreement:05 Feb 2016
Amount in SEK:SEK 151 million
Amount in EUR:EUR 16 million
Maturity:25 years
NACE sector / loan type:Sewage and refuse disposal, sanitation and similar activities

This loan contributes to climate change mitigation: 60%

Financing from NIB Environmental Bond proceeds

NEB-eligible share: 60%

NEB category: Water management and protection

Amount disbursed: EUR 9.5 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 to finance the construction of a new wastewater treatment plant with a high-rate clarification process for overflow running next to the existing Käppala wastewater processing facility in northern Stockholm, as well as for the construction of a new digester in the plant’s biogas production unit.

The Käppala plant is Sweden’s third largest wastewater treatment facility, processing 55 million m3 of sewage per year. The construction of the new high-rate clarification process plant will allow Käppalaförbundet to treat rising volumes of effluent water from a growing population and avoid overflow problems.

Apart from treating wastewater, Käppalaförbundet also produces biogas and high-quality sludge used as fertiliser. Currently, Käppalaförbundet operates two digesters for processing organic matter from wastewater with the capacity to generate 6.6 million m3 of biogas per year.

Due to the expected population increase in the region and Käppalaförbundet’s agreement with Stockholm’s regional bus transportation authority for the delivery of biofuel until 2026, a third digester is now required, which will be installed next to the existing digesters underneath the Käppala plant.

Both the high-rate clarification process plant and the new digester will be operational as of 2017.

Käppalaförbundet is a federation of eleven municipalities located north and east of Stockholm, first established in 1957. Today, the company treats wastewater from over 600,000 inhabitants. The Käppala plant is located in Lidingö.

Fulfilment of NIB's mandate

The project will support Käppalaförbundet’s efforts to ensure the efficient use of the existing infrastructure for sustainable water treatment in face of the anticipated population growth in the region. It is estimated that the high-rate clarification process plant will increase the treatment capacity of the facility and allow Käppalaförbundet to serve up to 900,000 inhabitants.

The high-rate clarification process of overflow technology has the purpose of avoiding discharge of untreated brown water directly into the environment in cases of exceptionally high precipitation. The construction of the new plant is not expected to negatively impact the environmental performance of the existing facility.

At the same time, the Käppala plant’s currently operating digesters for biogas production are running at almost full capacity, and a further increase in organic matter for processing could result in less biogas being generated or even jeopardise the whole process due to overloading. Installing a third digester will increase the biogas production capacity by 50% and secure the production process.

The extra biogas production capacity generated by the third digester will be used to treat external organic waste, household waste and industrial waste, resulting in additional vehicle gas production corresponding to 20,800 MWh a year.

Sustainability summary


The implementation of the project is assessed to have low potential for negative environmental impact.


Press release

NIB finances wastewater treatment for Stockholm

Press release

NIB finansierar avloppsrening i Stockholm