From Anaerobic Wastewater Treatment to Resource Factory – VEAS
The sewage company VEAS operates Norway’s largest wastewater treatment plant, serving around 650-700 thousand people and protecting the Oslofjord through advanced nutrient removal. The facility receives wastewater from the cities of Oslo, Asker and Bærum via a 42-kilometre gravity tunnel system that also recovers heat, supplying roughly 118 GWh annually to Oslo’s district heating network. After mechanical and chemical treatment of the wastewater, sludge is digested anaerobically, producing more than ten million Nm³ of biogas (2024 figures), largely upgraded and sold as bio-LNG. The remaining digestate becomes VEAS’ jord, a soil improver used in southeastern Norway, and ammonium sulphate fertiliser recovered through ammonia stripping. In 2024 the plant removed 79 percent of nitrogen and 92 percent of phosphorus.
At the time of drafting the Case story report VEAS was pioneering biogenic carbon capture and storage through HOOP, aiming to capture 7 thousand tonnes of CO₂ in 2025 and store it via the Northern Lights system. Key future developments include a new sludge treatment facility and ongoing efforts to reduce chemical use and support research on lowering nitrous oxide emissions.
This case study report has been drafted by IEA Bioenergy Task 37 (Energy from biogas).
Recent news on the project
End of March 2026 Norwegian company Inherit Carbon Solutions AS reported that it enter operation with the world first carbon removal project, based on the CO2 captured at the VEAS plant near Oslo. Read the press release.
