PFAS—per- and polyfluoroalkyl substances—are a group of synthetic chemicals that have become annoyingly pervasive in day-to-day life. First developed in the 1930s, these chemicals found their way into nonstick pans, waterproof clothing, stain-resistant carpets, and grease-resistant food packaging. to.

While PFAS made life more convenient, they’ve also introduced serious health concerns. Recent studies have connected PFAS exposure to various health issues, including thyroid disease, elevated cholesterol, liver damage, and even cancer.

These “forever chemicals” are nearly ubiquitous in the environment, showing up in the blood of most Americans and contaminating many drinking water systems. This widespread contamination prompted the Environmental Protection Agency (EPA) to establish the first federal limits on six types of PFAS in drinking water in April 2024. Despite these regulations, removing PFAS from water is no simple task.

Why you should care about PFAS in drinking water

PFAS are incredibly resilient. Ironically, this property makes them valuable in manufacturing but also means they don’t break down easily in the environment. This persistence has allowed them to accumulate over time, leading to widespread contamination. The United States Geological Survey (USGS) estimates that nearly half of all tap water in the U.S. is contaminated with PFAS.

The health risks associated with PFAS are alarming. In response to growing concerns, the EPA finalized regulations that set enforceable limits for six types of PFAS in drinking water systems. These limits, which range from 4 to 10 parts per trillion, highlight the extreme toxicity of PFAS—even tiny amounts can pose significant risks.

Before you can take steps to remove PFAS from your water, you should first know whether these chemicals are present. Public water systems in the U.S. are required to monitor for PFAS, and by 2027, they must all complete their testing. If your water comes from a public system, you can usually access water quality reports to check for PFAS. However, if you rely on a private well, you may need to conduct your own tests.

If you’re based elsewhere, your national or local water authority may have relevant information — or it may not. Testing for PFAS on your own isn’t cheap—sending a sample to a certified lab can cost between $300 and $600 in the U.S. —but it’s a crucial step in protecting your health.

How to filter PFAS

While the challenges of removing PFAS are significant, several filtration methods can effectively reduce these chemicals in drinking water. Each method has its strengths and limitations, so understanding your options can help you choose the best approach for your home.

1. Activated Carbon Filters

Activated carbon filters are one of the most common methods for filtering out PFAS from water. These filters use a form of carbon that has been treated to create a large surface area filled with tiny pores. As water passes through, the carbon adsorbs contaminants, trapping them in the filter.

Activated carbon filters can effectively remove many types of PFAS, particularly longer-chain compounds like PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate). This is the same technology used in many refrigerator and pitcher filters, such as Brita and PUR. However, not all filters are certified to remove PFAS, so it’s important to check the product specifications.

While activated carbon filters are relatively affordable and easy to install, they do have limitations. They may not remove all types of PFAS, especially the shorter-chain varieties, and they require regular replacement to maintain their effectiveness. Still, for many households, activated carbon filters offer a practical and effective way to reduce PFAS levels in drinking water.

2. Reverse Osmosis (RO) Systems

Reverse osmosis (RO) systems are another highly effective method for removing PFAS from water. This technology works by forcing water through a semi-permeable membrane that blocks particles larger than water molecules. As a result, PFAS and other contaminants are left behind, while clean water passes through.

RO systems are particularly effective at removing both long-chain and short-chain PFAS compounds, making them one of the most comprehensive filtration methods available. These systems are commonly installed at the kitchen sink for point-of-use filtration, providing purified water for drinking and cooking.

However, RO systems come with some drawbacks. They tend to be more expensive than other filtration options, both in terms of initial cost and ongoing maintenance. Additionally, RO systems can waste a significant amount of water—typically, they waste three to four gallons for every gallon of purified water produced. Despite these limitations, RO systems are an excellent choice for households seeking robust protection against PFAS and other contaminants.

3. Ion Exchange Filters

Ion exchange filters use a resin to remove undesirable ions from water, replacing them with more benign ones. This technology is commonly used in water softeners but is also effective at removing certain PFAS compounds. The resin in these filters is designed to attract and hold onto PFAS ions, effectively removing them from the water supply.

Ion exchange filters are particularly useful in areas with hard water, which can interfere with other filtration methods. These systems can be installed as part of a whole-house treatment solution, providing comprehensive filtration for all the water entering your home. However, ion exchange systems are more expensive and may require professional installation and regular maintenance to ensure optimal performance.

The Challenge of Disposing of PFAS Waste

While filtering PFAS from drinking water is important, it raises another significant challenge: how to dispose of the captured PFAS. These “forever chemicals” are notoriously difficult to destroy. Traditional disposal methods, such as landfilling, simply move the problem to another location without truly eliminating the contaminants.

High-temperature incineration, which requires temperatures above 1,800 degrees Fahrenheit (1,000 Celsius), is one method for destroying PFAS. However, this process is energy-intensive and costly, and there is still much to learn about the potential byproducts that could be created during incineration. Other emerging technologies, such as supercritical water oxidation and plasma reactors, show promise but face similar challenges in terms of cost and scalability.

Given these difficulties, the responsibility for managing PFAS waste will likely fall on public drinking water systems. The EPA has designated PFOA and PFOS as eligible contaminants for Superfund status, meaning companies responsible for contamination can be required to pay for cleanup. However, the EPA has also stated that it does not intend to target wastewater treatment plants or public landfills, leaving local governments and utilities to manage much of the burden.

Practical Steps to Reduce PFAS Exposure at Home

While public water systems work to meet the new EPA standards, there are steps you can take at home to reduce your PFAS exposure. Bottled water might seem like an easy alternative, but recent studies have found that even bottled water can contain PFAS. Moreover, bottled water is regulated by the Food and Drug Administration (FDA), which currently has no PFAS standards in place.

Instead, the best option is to use the same filtration technologies that public water systems will be employing:

• Activated Carbon: Available in many refrigerators and pitcher filters, activated carbon can capture PFAS from water, although its effectiveness varies. Ensure that any filter you choose is certified for PFAS removal.
• Ion Exchange Resin: Often used in home water softeners, ion exchange resin can effectively remove PFAS. This technology is available in some pitcher filters and whole-house systems, although it tends to be more expensive.
• Reverse Osmosis: Highly effective at removing a broad range of contaminants, RO systems are a good choice for kitchen-based filtration. They’re less practical for whole-house treatment but provide excellent protection for drinking and cooking water.

If you have a private well, the risks from PFAS are still present. In states like Wisconsin, as many as 71% of shallow private wells have some level of PFAS contamination.

For any filtration system, make sure the device is certified for PFAS removal by a reputable testing agency, and follow the manufacturer’s guidelines for maintenance and filter replacement. Unfortunately, there is no safe way to dispose of used filters that have captured PFAS—they must be discarded in the trash, potentially perpetuating the environmental cycle.

Looking Forward: The Future of PFAS Filtration

The battle against PFAS contamination is far from over, and as awareness grows, so too will the options for addressing this issue. Researchers are exploring new technologies, such as advanced oxidation processes and nanofiltration, that could offer more efficient ways to remove PFAS from water. However, these methods are still in the early stages of development and may not be widely available for some time.

At the same time, regulatory efforts are intensifying, with more stringent controls being placed on PFAS use in consumer and industrial products. These efforts, combined with improved waste management practices, will be essential in reducing overall PFAS contamination in the environment.

Conclusion: Taking Action for Safer Water

PFAS contamination is a complex and pervasive issue, but there are effective ways to protect your home and family. By understanding the available filtration methods—activated carbon, reverse osmosis, ion exchange—and staying informed about emerging technologies, you can make informed decisions about how to reduce your exposure to these harmful chemicals.

As the fight against PFAS continues, both at the regulatory level and within individual households, every step taken brings us closer to cleaner, safer water. Clean water is a fundamental right, and by taking action now, you can help ensure that right for future generations.