New treatmeant plant producing renewable energy

Wastewater treatment Solutions
The new treatment plant at Refne in the municipality of Halden is described by the municipality itself as its biggest and most important investment ever.

The old treatment plant needed to be upgraded to meet new requirements for treating emissions from the population of Halden. It was also necessary to expand the original plant to cater for expected population growth in Halden.

COWI looked after all the engineering disciplines for the project.
Now Halden has an ultra-modern municipal water treatment plant that meets environmental requirements and can also handle emissions from 42,000 inhabitants – so the town can grow substantially.

Alongside the upgrade to the treatment plant, a biogas plant has been built next door.
This means that energy generated by the treatment processes can be used to heat the building, and also to produce electricity.The long-term aim is to connect the biogas plant to the district heating network, and to supply future residential areas in the area with electricity. This also provides an economic benefit to the customer, who saves on costs previously incurred to remove and treat the sediment elsewhere.



Halden, Norway




Halden Municipality


  • Process/mechanical engineering
  • Civil engineering
  • Electrical, automation and HVAC systems
  • Fire safety
  • Acoustics
  • Environment
  • Energy
  • Building physics
  • Management, operation and maintenance
  • Landscape architecture
  • Geotechnics
  • Outdoor roads, water and drainage facilities

Get in contact

Erik Johannessen

Erik Johannessen
Market director
Industry and process, Norway

Tel: +47 488 96 684