Per- and polyfluoroalkyl substances (PFAS) are a family of thousands of synthetic chemicals used for decades in products ranging from firefighting foam to non-stick cookware. Their strong carbon-fluorine bonds make them highly persistent in the environment – even showing up in our drinking water – making handling these pollutants one of the biggest challenges amid the global water crisis.
An analysis by the Natural Resources Defense Council shows more than 73 million Americans are exposed to PFAS above EPA thresholds, pushing municipalities to address the challenge as regulations tighten. The EPA maintains maximum contaminant levels of 4 parts per trillion (ppt) for certain compounds, with compliance deadlines approaching for public water systems. In September 2025, the agency announced it would keep these standards while reconsidering regulations for four other PFAS compounds.
For water systems testing above these limits, three main treatment technologies emerge: granular activated carbon, ion exchange resins and reverse osmosis membranes. Each has advantages depending on water chemistry, but ion exchange offers a compelling option for the right applications. Let’s dig deeper into each method.
Choosing the right technology for your water
Granular activated carbon (GAC) offers a proven and versatile solution for PFAS removal through adsorption, where compounds bind to the carbon's extensive porous surface. One of GAC's greatest strengths is its adaptability—it performs reliably across diverse water qualities and provides the added benefit of simultaneously removing a broad spectrum of organic contaminants, making it an excellent multi-barrier treatment approach. While GAC does require more frequent media changeouts than ion exchange—typically three to five times more vessel volume for equivalent flow rates—and shows reduced effectiveness on short-chain PFAS compounds, its robust performance, operational simplicity, and ability to address multiple contaminants make it a valuable and widely trusted technology in water treatment applications.
Reverse osmosis separates PFAS through a physical barrier, with membranes removing more than 99% of most PFAS compounds, according to the National Institutes of Health. This technology handles the broadest variety of contaminants and tolerates difficult water chemistry that would foul ion exchange resins. The tradeoffs include roughly double the capital cost of adsorptive media systems, higher energy consumption for pumping and a concentrate stream containing 10-15% of the feed water volume at elevated PFAS concentrations.
Ion exchange systems employ resins that rely on both charged sites and van der Waals forces to attract and bind PFAS molecules. This dual mechanism combines electrostatic attraction with van der Waals forces, greatly increasing the attractive force. This greater attraction both adds capacity and accelerates kinetics, compared to carbon. For both sulfonates and carboxylates, ion exchange may provide three to five times more PFAS removal capacity per cubic foot of media as compared to activated carbon. The faster kinetics allow for contact times of two to three minutes per vessel compared to 10 minutes for carbon, which in turn allows for the use of smaller vessels and system footprint. Despite higher media costs than carbon, the combination of higher capacity and smaller systems can yield lower lifecycle costs in the right applications. Finally, ion exchange may also outperform carbon in removing certain short-chain PFAS, like perfluorobutanoic acid (PFBA).
When to implement ion exchange
Ion exchange works best for clean groundwater characterized by low levels of total organic carbon (TOC), total suspended solids (TSS) and competing anions like nitrate and sulfate. When TOC exceeds 2 parts per million (ppm), organic compounds foul the resin surface. Nitrate levels above 10 ppm compete aggressively with PFAS for binding sites, reducing capacity. Manganese above 20 parts per billion can foul and block the active sites, creating a crust that blocks PFAS removal while the media still has theoretical capacity remaining. Any amount of oxidizers, like chlorine, damages the resin structure, and oil or grease fouls the surface irreversibly. Consequently, PFAS treatment systems often include multiple pretreatment stages to address these contaminants just prior to using ion exchange resin for effective PFAS capture.
While carbon has near-universal approval for drinking water treatment, ion exchange for PFAS has gained approval in only a handful of states, primarily California, New Jersey and others on the coasts.
The decision often comes down to source water type and treatment goals. Clean groundwater from wells positions ion exchange as a strong candidate. Surface water with variable quality favors carbon’s tolerance for co-contaminants. Complex wastewater or requirements for short-chain PFAS removal may require reverse osmosis despite higher costs.
How ion exchange worked in Bellmawr, New Jersey
In 2018, the Borough of Bellmawr faced a pressing challenge when testing revealed perfluorooctanoic acid (PFOA) at 25 ppt, perfluorooctanesulfonate (PFOS) at 15 ppt and perfluorononanoic acid (PFNA) at 10 ppt in well water serving 900 gallons per minute. With total contamination of 50 ppt, the municipality needed treatment to meet New Jersey’s strict standards and reached out to Veolia for help evaluating options.
Bed-loading studies comparing granular activated carbon and ion exchange predicted the resin was able to achieve as much as 480,000 bed volumes prior to breakthrough of 2 ppt of PFNA as compared to granular activated carbon’s significantly lower capacity estimated around 50,000 bed volumes. The groundwater source free from co-contaminants, low organics, and minimal suspended solids created ideal conditions for ion exchange. The higher capacity translated to lower lifecycle costs despite the more expensive media, making it the clear economic choice.
Veolia installed a permanent 10-foot diameter lead-lag vessel system using PFAS-selective resin. Since March 2023, the system has treated water to non-detect levels with no media exchange required. The project demonstrates how matching technology to water chemistry creates efficient, long-term PFAS treatment solutions.
Unlike traditional ion exchange applications that require periodic regeneration with chemical solutions, PFAS-selective resins operate as single-use media to avoid recontamination risks. Once the resin reaches breakthrough capacity, the entire media bed is removed and replaced with fresh resin, eliminating the complexity of regenerant handling and the challenge of managing highly concentrated PFAS solutions. The spent resin undergoes high-temperature incineration at permitted hazardous waste facilities. This single-use approach simplifies operations for water utilities while ensuring the actual removal of captured contaminants rather than transferring them to secondary waste streams that require additional treatment or disposal.
Managing PFAS waste after treatment
Every PFAS removal technology generates concentrated waste requiring proper disposal. Spent ion exchange resins join activated carbon, reverse osmosis concentrates and other PFAS-laden materials in needing management pathways that protect public health.
The EPA’s April 2024 interim guidance recommends two main approaches: high-temperature incineration at permitted hazardous waste facilities and disposal at Subtitle C hazardous waste landfills. Incineration uses time, temperature and turbulence to destroy PFAS compounds, with destruction and removal efficiencies reaching up to 99.9999% for certain PFAS compounds. Landfill disposal sequesters PFAS in engineered facilities with protective liners and monitoring systems, though this approach stores rather than destroys the compounds.
Finding facilities willing to accept PFAS waste has grown more difficult as regulations evolve. Managed PFAS waste increased by 354,000 pounds from 2020 to 2022, according to EPA data, and disposal capacity has not kept pace. Working with service providers that maintain audited, approved disposal outlets helps minimize potential liability exposure under CERCLA.
Moving forward with PFAS treatment
Veolia provides comprehensive solutions that empower municipalities to effectively manage the PFAS challenge. Our LEAPfasTM technology delivers PFAS-selective treatment using single-use resins as part of our end-to-end BeyondPFAS program, which covers everything from detection through disposal. This innovative approach aligns with GreenUp, Veolia's strategic program designed to accelerate ecological transformation and advance sustainable water treatment solutions.
Moving forward with Veolia means gaining access to the right technology for your specific water conditions. Ion exchange offers municipalities an effective tool for PFAS removal when water chemistry aligns with the technology's requirements and applicable treatment regulations. Clean groundwater sources with minimal organics and competing ions can benefit from the higher capacity, smaller footprint, and potentially lower lifecycle costs compared to activated carbon.
Contact our experts to evaluate whether ion exchange makes sense for your water system and develop a customized PFAS management strategy that meets applicable regulatory requirements while minimizing costs. Learn more about testing at Veolia's Port Arthur, Texas, facility here.
For more information on our PFAS solutions and to read our full technical disclaimer, visit this page.
Author | John Peichel
Global PFAS Growth Initiative Leader, Veolia Water Tech
