OUTPUT: PFAS risk assessment tool for cities

12 November 2025

EMPEREST output 2.2, developed by the City of Riga.

Due to their high mobility and persistence in the environment, PFAS compounds accumulate in water bodies, soil, plants, and air, posing a growing threat to public health and the environment. Despite widespread contamination cases across the EU and globally, PFAS are not yet actively monitored in drinking water and wastewater in many cities.

It is crucial for cities to proactively map PFAS sources and assess related risks.

In accordance with the Urban Wastewater Treatment Directive updated in November 2024, it is mandatory to conduct a risk assessment and monitor PFAS levels in both the inlet and outlet of wastewater treatment plants serving agglomerations of 10 000 population equivalents (PE) and above. In response to that, the expert group from Riga (City of Riga, Riga Technical University, and Riga Water Ltd.) developed a PFAS local risk assessment framework (download PDF) and a tool (download Excel file) to support local authorities in identifying contamination hotspots and implementing effective mitigation strategies.

The EMPEREST Excel-based tool offers an easy 8-step guidance for local authorities to perform PFAS risk assessment for aquatic environments in a municipality. It looks over the whole municipal water cycle starting from water abstraction, water treatment, water supply system, sewage collection, and sewage treatment to treated wastewater discharge.

The EMPEREST PFAS risk-assessment tool is available in English, Estonian, Finnish, German, Latvian, Lithuanian, Polish and Swedish languages.

During the development of the initial framework, the project identified possible PFAS sources in the nearby environment and narrowed down possible polluters within wastewater collection network. The framework was tested and enhanced with support from five municipal waterwork utilities who made their own PFAS risk assessment plans. Based on their feedback, a lighter version was launched, to support municipalities that do not yet perform a source tracking, but instead as a starting point want to understand the potential sources of PFAS contamination and start mitigating the risks.

The EMPEREST risk assessment tool contributes to the overall water utility risk management and thus strengthens the safe and sustainable management of drinking water resources and wastewater treatment in municipalities.

Read the PFAS risk assessment plan for local authorities (PDF), developed in the EMPEREST project by the City of Riga.