The transition to fluorine-free foam comes with challenges
Commercial service airports in the U.S. are moving through a major operational shift as fluorine-free foam (F3) options appear on the Qualified Products List (QPL) and approved for use in meeting ARFF requirements. For fire chiefs and airport executives, the work has to land cleanly in the station: keep trucks ready, keep change-outs controlled and reduce the chance that legacy aqueous film forming foam (AFFF) residue continues to show up after the switch.
A key challenge in this transition is managing residual PFAS. Conventional triple rinse methods can leave PFAS behind in piping and tanks that later leach back into contained liquids, commonly called rebound. By addressing rebound early, airports can simplify the transition and reduce the volume of wastewater requiring management and disposal.
Converting complex chemistry into a defensible field plan
Naples Airport Authority engaged Onterris to support the transition of its ARFF vehicles in preparation for fluorine-free foam. The delivery model centered on clarity and control: start with testing, then execute on-site with a process designed to reduce uncertainty, reduce waste and protect the discharge pathway from avoidable PFAS carryover.
A structured testing matrix evaluated more than 30 blends of cleaning chemistry and methodology to identify a rinsate that outperforms water-only rinsing and supports a cost-focused transition. That lab-to-field connection is what emerging contaminant programs require. It ties measurable performance to operational decisions a chief or executive can defend under inspection, public scrutiny and evolving regulation.
On-site cleanout with waste minimization built in
In June 2024, the team mobilized to the airport and completed cleanout and transition work on two ARFF vehicles. The process removed PFAS from the trucks, concentrated the waste volume and containerized it for off-site disposal to prevent any release into the environment.
This approach is designed for the realities of airport operations. It brings the work to the fleet, reduces downtime driven by transport and keeps coordination tight with the people responsible for readiness. It also avoids turning a transition into a long series of rinse cycles that create unnecessary volumes of wastewater.
These are the types of projects we excel at. To date, we’ve treated 17 billion gallons of PFAS impacted water, and in doing so, have acquired a lot of experience with what works and what doesn’t. For the Naples Airport Authority AFFF effort, we started in the lab, identified a cleaning solution with better performance characteristics than conventional tap water, and then optimized the process dialing in the right temperatures and times. From ‘a concept’ to project completion, finding solutions to today’s environmental challenges, that’s what makes this work satisfying.
A model for commercial airports
At Naples Airport, testing shows that the proprietary cleaning solution is more effective than a conventional triple rinse with water alone, with better rebound minimization and significantly smaller wastewater volumes. In practice, that means airport teams can complete a foam transition with less residual risk to manage afterward and less waste to move through disposal channels.
The project closed with the vehicles prepared for fluorine-free foam and a repeatable model for other airports facing the same transition pressure: use science-led testing to choose the right approach, mobilize on-site to protect readiness and design the cleanout to control rebound and minimize waste from the start.