PFAS guidance for Denmark

Danish guidelines for the investigation and remediation of PFAS contamination

In 2022, Ramboll, together with consultancy company Niras, prepared guidelines for the investigation and remediation of per- and polyfluoroalkyl substances (PFAS) contamination on behalf of the Danish regions. The aim of the guidelines is to share knowledge on the challenges when dealing with PFAS.

The guidelines contain chapters on the chemical and physical characteristics of PFAS, environmental fate, health impacts, existing threshold values, regulations and analytical methods to detect PFAS. They give recommendations for the investigation of soil, groundwater and surface water contamination as well as risk assessments. The guidelines also contain a chapter on PFAS remediation methods and describe the benefits and drawbacks of each.

Methods for analysis of PFAS

The project was initiated by the Danish environmental protection agency (EPA) to review and test the effectiveness of analytical methods. The aim was to get an overview of effective methods for PFAS analysis and how mature the each of the methods are. The review looks at methods used worldwide for different environmental media (soil, air, groundwater, surface water, biota (plants, fish etc)) and different groups of PFAS including precursors.

Different analytical methods will be tested on sites in Denmark with PFAS contamination and recommendations will be based on those that can successfully address the 22 PFAS compounds that are included in the EU Drinking Water Directive, and that are able to analyse for PFAS precursors.

The project was carried out in collaboration with Eurofins, The Danish Regions, The Department of Defence, Niras, The Geological Survey and the University of Copenhagen.

Background levels of PFAS in soil groundwater and surface water

For the Danish EPA, Ramboll has also conducted an international literature review and national collection of data to establish the background levels of PFAS in soil, groundwater and surface water. The background level is defined as the level of PFAS due to diffuse contamination sources such as air pollution.

The aim is also to describe background levels in different environmental settings, for example in urban areas versus on agricultural farmland.

The results of the project show that data is sparse. Levels of diffuse contamination were expected to be far below quality criteria, but the data shows that there are several instances of diffuse concentrations close to or even exceeding quality criteria for PFAS, which will require further reductions in laboratory the detection limits in order to meet recent decreases in quality criteria.