All agreed loans

Sweden. Municipality of Strängnäs

Date of agreement: 12 Nov 2020
Country: Sweden
Customer: Municipality of Strängnäs
Amount in SEK: SEK 280 million
Amount in EUR: EUR 27.16 million
Maturity: 25 years
NACE sector / loan type: Collection, purification and distribution of water


The uncommitted credit facility has been provided for the Municipality of Strängnäs’ investment programme for wastewater infrastructure projects between 2020 and 2024.

The projects include closing the old and inefficient Mariefred sewage treatment plant, the upgrading and expansion of the central Strängnäs sewage treatment plant, and a sewage pipeline to connect the two localities. There are also large investments into the expansion and improvement of the existing pipeline network.  The total investment cost for the projects is SEK 561.6 million.

With a population of 36,544 inhabitants at the end of 2019, Strängnäs is one of the oldest towns in the County of Södermanland, located on the shores of Lake Mälaren in eastern Sweden.

Fulfilment of NIB's mandate

The investments will ensure optimum economic use of existing infrastructure and sufficient flexibility for future needs by the expansion and upgrading of the waste water treatment and bio gas production in Strängnäs.

The treatment capacity at Strängnäs will increase from 34,000 to 50,000 population equivalents (PE).

Sludge treatment will include biogas production, generating approximately 800 MWh thermal energy and 600 MWh electricity. The energy will be used to operate the plant, covering approximately half of the annual energy need.

Apart from gradually accommodating higher waste loads from a growing population in the region (around 1.5% annually), these projects will enable a centralisation of wastewater treatment. A new 23 kilometre sewage pipe from Mariefred to Strängnäs will enable the closing down of the Mariefred wastewater treatment plant, which lacks a nitrogen removal step and has capacity constraints. The transfer of the wastewater from Mariefred to Strängnäs is estimated to reduce the discharged nitrogen load by approximately 10 tonnes annually.

Estimated impacts related to the investments:

  • Added wastewater treatment capacity 16,000 population equivalents
  • Added renewable energy generation (biogas) from sludge treatment: 800 MWh thermal energy and 600 MWh electricity
  • Reduction of nitrogen discharges 10 tonnes annually

Sustainability summary

The wastewater treatment plant is centrally located in Strängnäs and construction work in the plant area may cause temporary nuisance to nearby residents due to increased traffic, noise and dust emissions. The construction work connected to the new sewer pipeline from Mariefred and upgrading of the sewer system have limited environmental impacts.

Press release

NIB tecknar avtal om låneram för modernisering av vatteninfrastrukturen i Strängnäs