Land used for fire-fighting training can remain polluted for decades if aqueous film-forming foams were used. Many older foams contained PFAS, including PFOS and PFOA. These chemicals resist heat, water, and natural breakdown, so they can persist in soil and ground water long after the source has ceased. A site last used for training 30 years ago can still act as a source if PFAS remain bound in soil and then leach into ground water during rain or changes in water level. This means that “old” contamination does not mean “spent” contamination. (US EPA)
If local water tests show PFAS at 40,000 times a recognised safe level, the first aim should not be full land repair. It should be exposure control. That means stopping use of polluted water, supplying clean water, testing private wells and surface water, and fitting treatment where water enters buildings or at the tap. The most proven water treatments are granular activated carbon, ion exchange resin, and high-pressure membranes such as reverse osmosis. These can reduce PFAS in treated water within days or weeks once designed, installed, and run well. Yet they do not destroy PFAS. They move PFAS from water into carbon, resin, brine, or membrane waste, which then needs safe disposal or further treatment. (US EPA)
Repairing the land and aquifer is slower and more uncertain. For soil, the most realistic methods include excavation and disposal, soil washing, thermal treatment, or stabilisation with sorbents such as activated carbon. Excavation can remove a clear “hot spot”, but it can be costly and may only move the waste elsewhere. Stabilisation can bind PFAS in soil and reduce leaching, but it does not remove the chemicals. Thermal methods may destroy some PFAS, but they need high technical control and can raise concern about air emissions and incomplete destruction. ITRC notes that many standard clean-up methods, such as air stripping or bioremediation, work poorly for PFAS because the chemistry is so stable. (pfas-1.itrcweb.org)
For ground water, pump-and-treat can contain a plume and lower PFAS in extracted water, but it tends to require long-term running. This is due to “back diffusion” and slow release from soil, sediment, and less mobile zones. In plain terms, even when polluted water is pumped out and treated, more PFAS may seep back into the water from the surrounding ground. Barriers that contain or adsorb PFAS in the ground may help, but they also need long-term monitoring and may later need renewal. (gov.je)
The likely time scale therefore splits into two parts. Treated household water can improve quite fast if a sound system is installed and maintained. The wider site and aquifer may take many years, and in some cases decades, to reach lower levels. At very high readings, it would be rash to promise quick remediation. A credible plan would require independent site mapping, repeated sampling, clear plume models, immediate clean-water measures, source removal where feasible, long-term treatment, and public reporting. The honest claim is not that the land can soon be made normal. It is that exposure can be reduced while a long, costly, and uncertain clean-up proceeds.
References
Interstate Technology and Regulatory Council. (2025). PFAS technical and regulatory guidance document: Treatment technologies. Interstate Technology and Regulatory Council.
United States Environmental Protection Agency. (2018). Reducing PFAS in drinking water with treatment technologies. United States Environmental Protection Agency.
Tshangana, C. S., Nhlengethwa, S. T., Glass, S., Denison, S., Kuvarega, A. T., Nkambule, T. T. I., Mamba, B. B., & Alvarez, P. J. J. (2025). Technology status to treat PFAS-contaminated water and limiting factors for their effective full-scale application. npj Clean Water, 8, Article 41.
