Supporting urban growth and reducing nutrient loads to the Baltic Sea

29 August 2019
Syvab has selected Ramboll as main consultant for a new wastewater treatment plant with MBR to meet increasing wastewater volumes and stricter demands for nutrient reduction in treated water released to the Baltic Sea, an investment exceeding a Billion SEK. Ramboll is also contributing to a pre-study together with Syvab on future treatment methods to reduce the discharge of micro pollutants such as pharmaceutical residuals and microplastics.



Annika Andersson Fräs

Annika Andersson Fräs

Head of Department
T: +46 (10) 6156533
M: +46 (72) 1468233

Anna Hamrin

Head of Department, Water and wastewater treatment, biogas
T: +46 (10) 6154980
M: +46 (70) 5944980
Johanna Grim

Johanna Grim

Project manager, consultant
T: +46 (10) 6156636
M: +46 (70) 4840156

By Martin Zoffmann

The countries surrounding the Baltic Sea have agreed that each country must reduce its discharges of nutrients into the sea. It mostly concerns nitrogen and phosphorus and the goal is to reduce eutrophication to the same level as the 1950s. To support this positive development, and to meet new requirements, Syvab (The Regional Wastewater Treatment Company of Southwest Stockholm) is investing more than a Billion Swedish Kronor in expanding and improving the wastewater treatment plant ‘Himmerfjärdsverket’.

The project, ‘Nya Krav Himmerfjärdsverket’ (New Demands Himmerfjärdsverket), is one of the biggest and most important current projects of its kind in Sweden and includes implementation of the ‘Membrane Biroreactor technology’ (MBR), which is a very efficient method for nutrient and solids removal. As the main consultant for Syvab, Ramboll has in collaboration with Syvab preparing this project since 2013 and is now designing the main biological treatment process.

“We are proud and happy to collaborate with Syvab on this important and technically attractive project. We look forward to improving Himmerfjärdsverket with state-of-art technology, and we fully share the ambition of creating a treatment icon that leads the way on an international scale,” says Annika Andersson Fräs from Ramboll’s water division.

Stockholm is one of the fastest growing cities in Europe and the ongoing urbanization directly drives water and wastewater capacity issues. Today, Himmerfjärdsverket treats the wastewater from 335,000 people in households, institutions and industries in southwest of Stockholm. This number is expected to increase to 433,000 by 2040. Also, more strict environmental regulations demand new top-of-the-line wastewater treatment.

Pre-study on medical residues

Ramboll has also been asked to participate in Syvabs pre-study on the removal of medical residues and other micro pollutant. The study, which is financed by the Swedish Environmental Protection Agency, will assess the efficiency of removing micro pollutants through granulated activated carbon filters. It will also investigate and compare the environmental effects of this technology with the technology used today.

The pre-study will be delivered to the Swedish EPA by the end of October 2019, and the new and improved Himmerfjärdsverket will be ready and operational in 2026.


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