Zero waste: Audi tests sustainable water cycle
With its Mission:Zero environmental programme, Audi has not only set its sights on the decarbonisation of its production sites, but also on a sustainable water supply for its plants by 2025. The pilot project is already underway.
Audi’s commitment to sustainability is also reflected in its responsible use of natural resources. That’s why the company’s Mission:Zero environmental programme aims not only to decarbonise its production sites, but also to establish a sustainable water supply.
The Neckarsulm plant will become wastewater-neutral by 2025 thanks to a closed water cycle, which will be implemented by using the “Unteres Sulmtal” association’s sewage treatment facility adjacent to the site. Before the cycle and the associated construction of a new water-supply system in the plant can start, Audi will test the closed water cycle process with a pilot facility.
Emissions and sustainability

“In addition to the avoidance of CO2 emissions, sustainable water use plays a key role within the context of our Mission:Zero programme. With this treatment facility in close proximity to our plant, we have a unique setup that we can draw great benefit from in the future,” explains Achim Diehlmann, Head of Operational Environmental Protection at the Neckarsulm location and the project leader for Mission:Zero.
Starting in 2025 at the latest, the water required for the entire plant will be run through a closed circulation system, and the production at the location will be wastewater-neutral.
Water quality

The new water-supply facility will be online by 2025. But, prior to its construction, the process will be tested extensively with a pilot facility in the northern area of the plant. To that end, test pipes have already been laid to run the water from the treatment plant’s final inspection area to the pilot containers and back again.
In the container, the water is treated for use in production by running it through special filter systems and membranes. During the process the facility continually measures the water quality, with a laboratory analysing the water’s properties every two weeks.
“If everything works out and the water consistently meets our target values, we can start on construction of the new water-supply facility at the end of 2022,” says Christian Forelle, who is heading up the project.
The Neckarsulm model
The Neckarsulm plant is supplied with around 600,000 cubic meters of water for production every year – equivalent to about three million bathtubs. The water currently comes from the Neckar Canal, with a facility built in 1964 processing it for use in production.
The plant has taken advantage of its proximity to the city’s treatment facility in the past as well. For instance, the factory has had a direct wastewater line from the paint shop to the treatment facility for years, allowing wastewater to be fed directly into the facility rather than first into the sewer system.
Mission:Zero
To reduce its ecological footprint in production and logistics, Audi is updating all its activities and processes through the Mission:Zero environmental program. It is focusing on the central challenges of decarbonisation, the efficient use of water and other natural resources and on biodiversity. A central goal is to achieve carbon neutrality at all its production sites by 2025.
Source: AUDI AG