Simmering main sewage treatment plant: 45 years of environmental protection and innovation!

Simmering main sewage treatment plant: 45 years of environmental protection and innovation!

The main sewage treatment plant in Simmering has reason to celebrate: its 45th anniversary was celebrated on June 30, 2025, and the city of Vienna can look back on 45 years of serving the environment and wastewater treatment. The important facility was opened by Leopold Gratz, the then mayor of Vienna, and it bears the title of the largest environmental protection project of the Second Republic of Austria. On average, more than 200 million cubic meters of wastewater are treated here every year - an impressive amount that underlines the city's commitment to sustainability.

Covering an area of ​​around 47 hectares, larger than the Vatican, the wastewater treatment plant has purified an incredible 8.7 trillion liters of wastewater since it began operation. This corresponds to more than twice the volume of Lake Attersee! Over the last 45 years, the City of Vienna has invested around 750 million euros in expanding and converting the facility, showing that it is not just a project, but an ongoing commitment to the future environment.

Eco power plant and modern technology

The main sewage treatment plant is not only dedicated to the purification of wastewater, but also scores points with innovative technologies. It produces more energy from sewage gas than it consumes and is therefore also known as an “eco-power plant”. The facility also provides health data through wastewater monitoring, which was introduced in 2020 during the Covid-19 pandemic. Such modern developments are essential for health and environmental protection in the city.

There have been several significant expansions in recent years: in 2023, a large heat pump system was put into operation, enabling the wastewater treatment plant to generate district heating for over 100,000 households. In addition, Mayor Michael Ludwig was present at the introduction of renewable energy generation in 2020, while his predecessor, Mayor Michael Häuptl, accompanied the commissioning of an expanded biological purification stage in 2005.

New order for greater efficiency

In order to further increase efficiency, the city of Vienna recently awarded a major contract to PROBIG. In cooperation with Ginzler/Amstetten, conveyor scrapers are provided for the system. The aim is to ensure that the wastewater treatment plant remains state-of-the-art. The order volume for PROBIG is around 1.8 million euros and aims to introduce modern chain scrapers made of high-quality plastics that are TÜV tested and certified. This is another step towards energy self-sufficiency, which was targeted for 2020 and is now focused on the implementation of high technology.

In summary, the milestone anniversary of the sewage treatment plant in Simmering not only shows the successes of the last 45 years, but also looks into a promising future. With continuous investment and a clear focus on sustainable technologies, the facility remains an example of ecological commitment and innovative solutions to serve the public.