1.2 million euros for PFAS research

The Ministry for the Environment, Climate, and Energy Sector is providing 1.2 million euros for the SPIRIT research project – “Strategies for in-situ PFAS remediation using innovative technologies.” The study is examining approaches that could potentially be applied to soil contaminated with PFAS (per- and polyfluoroalkyl substances) in the Rastatt/Baden-Baden and Mannheim regions.

“PFAS pose a threat to both people and the environment. We must prevent them from entering the soil and water any further. Where this has already happened, we must seek out effective methods of removing or neutralizing these persistent chemicals. We support the SPIRIT research project because it has the potential to move us a significant step forward,” says Thekla Walker, Minister of the Environment for Baden-Württemberg.

In Central Baden and Mannheim, approximately 1,700 hectares of farmland are contaminated with PFAS. The contamination caused by compost mixed with paper sludge has already seeped into the groundwater. Drinking water sources in the Rastatt/Baden-Baden area have also been affected. Law enforcement agencies have been investigating the incident since 2013. By mid-2025, public spending on this reached approximately 26 million euros. To ensure consumer safety, long-term measures must be taken in the areas of water supply and agriculture.

The contaminated soil contains a substantial reservoir of immobile PFAS precursors. Without remediation measures, mobile PFAS will continue to seep from this reservoir into groundwater for decades to come. For this reason, further contamination has often been prevented through local soil replacement or soil sealing. There is an urgent need for a method to remove PFAS from soil without excavating it (in-situ remediation).

To this end, a research project conducted by the Research Facility for Groundwater and Contaminated Site Remediation (VEGAS) at the University of Stuttgart, in collaboration with the DVGW Technology Center for Water (TZW), is investigating three promising approaches to in-situ remediation technologies for soils in the Upper Rhine Plain. In the first phase of the project, these technologies will initially be tested in the laboratory. The aim is to use heat to release PFAS precursor substances bound in the soil (thermal desorption) or to mobilize, capture, and remove them through accelerated microbial transformation. The study is also examining whether the groundwater beneath the soil can be protected by strategically placed drainage systems. In the second phase, the approaches that have been successfully applied in the laboratory will be tested in field trials in the Rastatt district and the city of Baden-Baden. Results from Phase 1 of the project are expected in February 2027.

Per- and polyfluoroalkyl substances (PFAS, “forever chemicals”) are currently one of the biggest environmental problems we face. They were first identified in the 1950s, are now ubiquitous worldwide, pose serious risks to human health, and in some cases are even carcinogenic. The group of substances is large; there are thousands of individual substances, only a few of which can be analyzed quantitatively. Some PFAS are mobile and are therefore easily transported through the soil and leach into the groundwater. Others bind strongly to the soil, which prevents leaching. Despite the differences in the properties of these substances –and thus their transport characteristics in the subsurface – they all have one thing in common: each substance contains fluorine-carbon bonds. These bonds are very stable, contribute to the persistent nature of PFAS, and, together with their distinct transport properties, are the reasons why there are currently very few in-situ remediation technologies in use. To date, PFAS have been removed from contaminated water using various treatment techniques – for example, at water treatment plants – but not at the source of the contamination in the soil. 

Further information
PFAS in Baden-Württemberg
Status report on PFAS contamination in the Rastatt/Baden-Baden and Mannheim Regions [de]
Project page VEGAS