Topping out for modern sewage treatment plant: Heidenheim invests 54 million euros!

Topping out for modern sewage treatment plant: Heidenheim invests 54 million euros!

There is currently a lot of work going on in Mergelstetten: On Friday, July 11, 2025, the topping-out ceremony for the Heidenheim district's new sewage treatment plant was celebrated. This ambitious project is worth around 54 million euros and aims to modernize the existing infrastructure and meet increasing legal requirements. This means that the sewage treatment plant in the district will be able to work more efficiently and in a more environmentally friendly manner in the future, which also enabled access to important funding of over 192,000 euros for upgrading the plant, as the city of Heidenheim announced.

The old sewage treatment plant currently purifies around 60 percent of the district's wastewater. But times are changing: the technical infrastructure is outdated and comprehensive retrofitting is unavoidable. Particular challenges for the new construction work are nitrogen elimination and the removal of micropollutants, which are becoming increasingly important in modern wastewater management. Innovative process technology is used to clean wastewater more efficiently and even reduce energy costs.

The construction progress and planning

The groundbreaking ceremony for the new facility took place in autumn 2023, and since then almost 10,000 cubic meters of concrete have been processed. A total of around 18 million euros has already been invested. The construction project will be carried out in sections in order not to endanger the ongoing operation of the existing sewage treatment plant. Project manager Steffen Abele and construction manager Steve Lehnert emphasize the high complexity of the construction project and the excellent cooperation between planners, construction company and administration.

The planned measures include the construction of a new pumping station for the biological stage and the renewal of primary and surplus sludge pumps. These measures are not only part of accelerated implementation, but also crucial for saving energy costs and reducing greenhouse gas emissions. The processes should also enable optimized performance in nitrogen treatment.

Technical innovative strength

The new concept also envisages integrating a crane into the system to simplify maintenance measures. In addition, the heights of the structures were optimized in order to reduce the pumping capacity. All technical innovations are designed to adapt the sewage treatment plant to modern environmental standards and to make it energy efficient and automatable. By the planned completion of construction in 2029, the sewage treatment plant should meet all the requirements of the overarching environmental regulations and thus make an important contribution to the clean environment in the district.

The project is not only supported by the city of Heidenheim, but also includes the communities of Herbrechtingen, Steinheim am Albuch, Gerstetten and Nattheim. Mayor Salomo joined the symbolic topping-out ceremony with site manager Lehnert and looked optimistically into the future of the project and its impact on the regional environment.

Thanks to the national climate protection initiative and its funding priorities, it is ensured that innovative and climate-friendly solutions can be implemented in wastewater management, such as this klimaschutz.de reports. It remains to be seen how the new technologies and processes at the wastewater treatment plant in Mergelstetten will ultimately help reduce the region's ecological footprint.