Per- and Polyfluoroalkyl Substances (PFAS) are a diverse group of synthetic chemicals used for over 50 years in industrial applications, consumer products and firefighting foam.
‘Forever chemicals’ such as PFAS take many hundreds of years to break down in the natural environment and their potential effects on human health are not fully understood. European regulations and guidelines are now in place to protect the soil, groundwater and surface water from PFAS contamination. Reducing PFAS through remediation is therefore a high priority for the regulators and landowners.
Our team was appointed to evaluate PFAS contamination from the use of firefighting foam at a German military airfield, and then identify potential mitigation strategies to remove them. Our end objective was to present the findings to the German regulators to obtain permission to proceed with the next round of investigations, a feasibility study as well as the final remediation stages.
‘Forever chemicals’ such as PFAS take many hundreds of years to break down in the natural environment and their potential effects on human health are not fully understood.
Doing the research
Building up a detailed picture of current and historic activities at the airfield allows us to determine all PFAS migration pathways into the soil, groundwater, surface water, storm water and any storage locations.
We began with a desktop review of all available relevant documentation, including existing reports and records, local maps and all scientific data pertaining to the site and adjacent properties. Following the initial data collection stage, our team made a series of site visits to identify and map all possible discharge points.
Often, people have a lot of valuable information that can help us understand how a facility has been used in the past, so we also conducted interviews with key personnel.
Once we had all the information, we identified the data gaps and carried out additional, non-intrusive sampling where needed.
Clear recommendations for the next stage of targeted action
The information allowed us to create a site characterization plan (SCP) of the entire airfield that mapped identified and potential PFAS contamination both on the site and in adjacent areas. We built a conceptual site model that identified relevant potential release and exposure pathways. We used these models to create sampling and analysis strategies to understand in more detail the environmental impacts to soil, to storm water discharge, the water catchment and sewer system as well as groundwater. We also proposed mitigation strategies for all media at these specific sites.
In addition, as well as the identification of potential remediation technologies to consider in future remedial activities and designs, we prepared cost estimates for current and future site investigations.
Collaboration and communication key to a successful outcome
Given the complexity and scope of the project, it was vital to work closely with all parties from military personnel to local authorities and other stakeholders right from the start to ensure the project was well-coordinated and to develop the mitigation strategies. We also presented the findings – the draft SCP plan outline, sampling and analysis plan – to the regulator in a series of regular project meetings.
By providing a clear roadmap for identifying and managing the potential risks, local authorities concurred that the project could progress to the remedial investigation and feasibility study stages in accordance with legal requirements.