Modernised wastewater treatment plant enhances water protection and energy efficiency
The ARA Basel was officially opened on 17 April 2026. Following the refurbishment and expansion work that began in 2019 and has now been completed, it is one of the most modern wastewater treatment plants in Europe. It will open its doors to the public on 18 and 19 April.
The refurbishment and expansion of the Basel Wastewater Treatment Plant have been completed. The wastewater treatment plant was officially inaugurated on 17 April. One of the region’s most important infrastructure facilities had been thoroughly modernised and expanded whilst remaining in operation since 2019. It is now one of the most modern facilities of its kind in Europe. Over the weekend of 18 and 19 April, the public can see it for themselves during the open days.
According to a statement from the Canton of Basel-Stadt, the aim of the project was to significantly improve treatment performance, adapt the plant to future requirements and make a long-term contribution to water protection. It is now state-of-the-art and ensures legally compliant operation for several decades. It is designed to have a capacity sufficient for 520,000 residents until 2050. It can also receive pre-treated industrial wastewater from the ARA Chemie.
Following the modernisation, the Basel WWTP is now also equipped for nitrogen removal and features a treatment stage for reducing micropollutants. This is complemented by sludge digestion and photovoltaic systems. Furthermore, biogas is produced from sewage sludge digestion and more waste heat is fed into the district heating network.
The operator of the Basel wastewater treatment plant is Prorheno AG. The parliaments of the two Basel cantons approved CHF 325.1 million for the plant’s refurbishment. The final accounts are not yet available.