Perfluoroalkyl and polyfluoroalkyl substances, more commonly known as PFAS, are chemicals found in a variety of consumer, commercial and industrial products for the last 70+ years. There are thousands of varieties of these chemicals. They are found in everyday occurrences like in clothing to resist stains and in cookware to prevent sticking. Bound with non-degradable carbon-fluorine bonds, PFAS is deemed a “forever chemical.” This makes it not only bad for exposure for humans but also for the environment. Exposure can occur through many paths: contaminated water, through touch of PFAS-laden products and even inhalation. Like the more well-known dangers of lead, PFAS build up in the body over time

The majority of people have been exposed (~98%), whether at a large or small scale. Decreased fertility, developmental delays in children, heightened cancer risk, reduced immune system function and higher cholesterol levels are some of many adverse health effects. Due to there being 14,735 individual PFAS chemicals, it is difficult to know information about all types and their long-term effects specifically. In fact, PFAS is such a concern that the 2021 Bipartisan Infrastructure Law allocated $5 billion to PFAS monitoring and remediation.

Time is of the essence, as public water systems are currently undergoing initial PFAS monitoring between 2024 and 2027. Between the conclusion of this monitoring in 2027 and 2029, water systems will release information to the public via consumer confidence reports or annual water quality reports. By 2029, systems that violate any of the above maximum contaminant levels (MCLs) will be required to take action immediately and notify the public. It is projected that some 4,100 to 6,700 water systems will need to be upgraded or moved to accommodate PFAS limits.

PFAS in drinking water

One of the largest sources of PFAS contamination is in drinking water. Industrial processes release it into air, Earth and water, sewage discharges, landfill leaches and in firefighting foam. There is no shortage of methods of exposure — and they are unavoidable. PFAS do not break down in boiling water, either. Any contaminated water drunk or used for cooking is game for contamination. The U.S. Geological Survey (USGS) conducted a test directly from people’s kitchen sinks across the nation and concluded that nearly half (45%) of them had PFAS present in their water. This was a recent study across 716 sampling locations of both public and private water supply. This proves a serious and ongoing concern.

Source: USGS

In 2024, the U.S. Environmental Protection Agency (EPA) issued the first National Primary Drinking Water Regulation (NPDWR) for six PFAS chemicals. Two of the most commonly used and produced ones on this list are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) which allow zero, but four parts per trillion is the enforceable limit. The remaining three single chemicals allow only 10 parts per million and one combination mixture is one.

The solutions

The EPA recognizes three treatment options available for PFAS removal. This includes granular activated carbon, ion exchange resins and high-pressure membrane systems. There are also innovative approaches such as cavitation via a hydrodynamic reactor as found by Oxford Brookes University researchers and ball milling as reported in the American Chemical Society (ACS) Environmental Science and Technology Letters.

Granular activated carbon is the most researched and used method. It uses a process labeled adsorption. The carbon is made of organic materials like wood, lignite and coal. Since carbon is very porous, it can remove 100% of PFAS based on many factors: carbon type and amount, PFAS type, water flow rate, temperature and other organic compounds present. Oftentimes the water is run through a sand filtration first as well. This method works the best on PFOA and PFOS since they have longer chains. One great aspect of this approach is that the carbon can be reactivated. A downside is that the PFAS will also need to be disposed of after this process.

Ion exchange resins utilize another porous material — hydrocarbons — that are also insoluble. Cationic processes remove contaminants of a positive charge while anionic processes remove the negatively charged PFAS. The removal of PFAS is like magnets, but it is an expensive procedure. Single-use PFAS-selective classes are the most effective. Disposal of the resin is needed in this method, but there is no liquid contamination that occurs. Based on type of PFAS and resin, resin depth, flow rate, degree and other contaminants, ion exchange also removes 100% of PFAS.

Finally, nanofiltration and reverse osmosis fall under the high-pressure membrane systems method. Reverse osmosis is a bit more effective of the two. This approach works well with shorter chain PFAS and removes up to 90%. Meanwhile, 80% of the water passes through the membrane and 20% becomes a concentrated waste. This waste stream poses a challenge for large-scale water systems, so this approach is more suited for at-home treatment. The treated water can be highly corrosive, and care needs to be taken to ensure lead and copper in existing water systems are not damaged.

Oxford Brookes University researchers utilized cavitation — which just creates air bubbles to remove the PFAS in an eco-friendly and energy-efficient manner. No additional chemicals were needed and 36% of the pollutants degraded in just 30 minutes. They are working to boost the volume of treatable water to 20 liters and then 200 liters to use at a wastewater treatment plant in Sweden. Ball milling actually uses metal balls and physically collides with the strong carbon-fluorine bonds to break them. Potassium hydroxide was typically used but is corrosive and causes clumping. Boron nitride is now being used and was able to remove all the fluorine atoms in four hours at ambient temperature and pressure. The boron nitride even worked more effectively than the potassium hydroxide. There is much continuous research to locate better, cheaper and more effective ways to remove PFAS.

Typical at-home water filtration systems like Brita and Pur are not designed to remove PFAS. They are strictly focused on taste and smell. It is recommended to choose a filter with an independently tested certification for PFAS removal. This ensures that a lab has thoroughly tested it. Certifications from National Sanitation Foundation (NSF), Water Quality Association (WQA), International Association of Plumbing & Mechanical Officials (IAPMO), UL Solutions, CSA Group and Intertek (ETL) are recommended options.

In fact, NSF announced the first company to designate a pipe as NSF and PFAS Tested, the PPI Pipe Co. Ltd. It passed testing for all six regulated PFAS compounds that are regulated by EPA and one additional. It is their hope that this will help the general public to learn about and care about the dangers of PFAS. This designation applies to their PVC pipe as well as pipe fittings.

The unknowns

One of the most alarming aspects of PFAS is the sheer amount of information still not known about them. The EPA states that there is still ongoing work to learn detection measures, exposure levels, true dangers, removal and disposal methods. Currently, the following organizations are conducting research on these dangerous chemicals: The National Institute of Environmental Health (NIEHS), the Centers for Disease Control and Prevention (CDC), the U.S. Food and Drug Administration (FDA), and the U.S. Department of Defense’s Strategic Environmental Research and Development Program. Initial monitoring efforts between 2024 and 2027 will give more insight into the status of PFAS in the water supply by 2029. It is critical that water systems ramp up their monitoring and prepare for PFAS removal systems, new supply locations, and allocate appropriate funds to meet all new EPA MCL standards. Research is of utmost importance and avoidance of PFAS chemicals is pertinent to maintaining health and integrity of the planet.