PFAS Mitigation

Preventing “forever chemicals” in our air

The Problem: Forever Chemicals are Pouring from Landfills 

PFAS chemicals, the toxic “forever” compounds that make food boxes grease-proof, carpets stain-resistant, and jackets shed rain, don’t magically disappear once we toss them in the trash. They end up in landfills where, instead of breaking down, they slowly work their way back into our environment…and into the water we drink and the air we breathe.  And here’s the key thing a growing body of research tells us: PFAS doesn’t stay put. It leaves landfills in two major ways — through water and through air — and both pathways need real solutions in order to keep people safe.  

PFAS are harmful to people. Once they enter our bodies, they stick around for years and can interfere with the immune system, thyroid function, and healthy development. PFAS exposure has been linked to higher cholesterol, pregnancy complications, and certain cancers. These chemicals even cross the placenta and show up in breast milk, meaning exposure can begin before birth. And to understand why these two pathways exist, we have to understand what PFAS actually is.

One reason PFAS moves through landfills in different ways is because PFAS isn’t a single chemical — it’s a massive family of thousands of compounds. Some PFAS dissolve in water. Others evaporate into air. Some cling to plastics and clothing. Others break off coatings and enter soil.

The Problem: Forever Chemicals are Pouring from Landfills 

As waste decomposes, volatile PFAS, especially fluorotelomer alcohols (FTOHs), evaporate, attach to landfill gas, and drift off-site unless they’re captured early and burned at high temperatures. 

Incomplete destruction of PFAS may result in Products of Incomplete Combustion (PICs), which further contribute to atmospheric warming. In the environment, FTOHs travel easily through the air and degrade into persistent PFAS that contaminate soil and water far from their source. In other words, FTOHs act like a mobile delivery system for PFAS pollution, spreading it quickly and making it harder to clean up.

FTOHs also transform inside the human body into other toxic PFAS that stay in the blood for years. FTOHs are a problem because they don’t just evaporate, they transform. Once inhaled, these volatile PFAS break down inside the body into other harmful PFAS that linger for years and are linked to immune suppression, thyroid disruption, developmental impacts, and certain cancers.

A nationwide study recently sampled landfill gas at 30 landfills across 17 states, finding PFAS levels in the tens of thousands of nanograms per cubic meter, with some sites far higher. Researchers estimated U.S. landfills release roughly 836 kilograms of PFAS into the air each year, and potentially much more depending on site conditions. Even spread over a year, that makes landfills one of the larger known sources of PFAS to the atmosphere, at concentrations in landfill gas that are hundreds to thousands of times higher than normal outdoor air. 

This aligns with earlier work by Lin et al., who found that many neutral PFAS (that can be found in both liquid and gas form) actually prefer the gas phase, meaning they escape through landfill gas far more readily than they dissolve into leachate. In several cases, these volatile PFAS were released almost entirely through gas.

And here’s the uncomfortable part: we’re flying nearly blind. Only a handful of studies have ever measured PFAS in landfill gas. Almost no landfills test the air at their boundaries. Monitoring of PFAS in waterways downstream of landfills is spotty at best. For chemicals that bioaccumulate and can negatively affect the immune system, thyroid function, and long-term health — whether inhaled or ingested — that lack of basic information is a problem. It doesn’t have to stay this way.

Solutions are Practical and Ready to Go

The fixes are remarkably practical, and several states are already pointing the way.

  • PFAS starts off-gassing long before many landfills install gas systems. States like California and Michigan are ensuring earlier gas collection for methane — a policy that would dramatically reduce PFAS emissions too.

  • Better gas collection system design and operation, as detailed in this brief, can significantly increase gas recovery and associated PFAs airborne emissions. 

  • PFAS breaks down best under high heat with good mixing and enough time in the flame. Enclosed flares are better than open or poorly run flares at maintaining these conditions, making them more likely to reduce PFAS, especially in landfill gas. States like Washington already rely on enclosed flares to improve air quality, and PFAS adds another reason to use them.

    Direct measurements of PFAS destruction in flares are still limited, and more field testing is needed to quantify performance. But based on what we know about combustion, well-operated enclosed flares are a practical step to reduce PFAS, alongside their proven benefits for methane and VOC control.

  • No landfill should be allowed to discharge PFAS into the air or water without measuring it. Right now, almost none do. EPA can change that by requiring PFAS monitoring for both landfill gas and leachate — and by setting standards based on what the science shows.

    Some landfills, like Smiths Creek in Michigan, are already piecing together what a whole-system solution looks like: pairing PFAS treatment for leachate with strong gas controls and continuous, high-temperature operation. It’s proof that the approach works.