Explaining the new federal regulation for PFAS in drinking water

The U.S. Environmental Protection Agency (EPA) recently announced the Final PFAS National Primary Drinking Water Regulation. 

Per- and polyfluoroalkyl substances, also known as PFAS, have been an issue of growing concern for decades because they can persist in the environment indefinitely. These “forever” chemicals have been in widespread use since the 1940’s, including at industrial sites, in firefighting foams and in certain types of nonstick cookware. 

Studies have linked PFAS exposure to a range of health problems, including some cancers, thyroid issues and immune system challenges. Health challenges are amplified for young children, during pregnancy and with long-term exposure. 

PFAS are mobile in surface or ground waters and can occur in sources used for drinking water. Therefore, addressing PFAS in drinking water is a critical public health issue. 

The importance of taking action is reflected in the fact that this is the first new federal drinking water limit change that has been made in over two decades. The EPA estimates this new regulation will prevent millions of serious illnesses and thousands of deaths over time by limiting PFAS exposure in drinking water. 

What are PFAS chemicals and where do they come from?

PFAS are known for their unique properties that make them valuable in a variety of products. For example, PFAS repel water, oil and stains, making them ideal for coatings on nonstick cookware, rain gear and carpets. Their ability to withstand high temperatures is useful in fire-resistant materials, fire fighting foams at airports and electrical insulation. Although several types of PFAS have been phased out, many are still widely used. 

PFAS contamination can come from a variety of sources, including manufacturing facilities that use PFAS in their products, municipal wastewater treatment plants, landfills and waste sites where improper disposal can lead to contamination of surrounding soil and water and sewage sludge treated with PFAS-containing materials.

The widespread use and persistence of PFAS have led to their presence in drinking water supplies across the country. PFAS can build up in the bodies of animals and humans, known as bioaccumulation, when ingested through contaminated water or food.

How prevalent are PFAS in Arizona’s drinking water systems?

The Arizona Department of Environmental Quality (ADEQ) has confirmed the presence of PFAS in public water systems across the state based on a screening program proactively developed in 2018. The agency is currently working to update their data in light of the new federal regulation, which will apply to approximately 950 water systems in the state.

It's important to note that most of Arizona's public water systems serve fewer than 3,300 people and the EPA's current testing requirements only apply to larger systems. However, in 2022, ADEQ and the Water Infrastructure Finance Authority of Arizona agreed to dedicate a portion of federal Safe Drinking Water Act funds to ensure every public water system in the state is tested for PFAS.

How is PFAS treated by municipal water providers?

Municipal water providers are currently addressing PFAS contamination in their water supplies. There isn't a one-size-fits-all solution, but several treatment technologies can be effective, depending on the type and level of PFAS present. 

For example, adsorption is a method that uses a special media, like granular activated carbon (GAC) or ion exchange resins, to capture PFAS molecules and remove PFAS from drinking water. GAC is a highly porous material that provides a large surface area for PFAS to cling to. Ion exchange resins work by attracting and exchanging charged ions, including some PFAS types.

The effectiveness of adsorption depends on several factors, including the specific PFAS, the capacity of the media and other co-occurring chemicals in water. PFAS accumulated on the GAC or ion exchange materials must be properly disposed of, or thermally regenerated.

Membrane filtration utilizes high-pressure membranes, like nanofiltration or reverse osmosis (RO), to physically separate PFAS from water. RO membranes are very tight and effectively remove most contaminants, including a wide range of PFAS. Membrane filtration is generally more expensive to implement and maintain compared to adsorption, and PFAS still occurs in concentrated brine waste streams that must be properly disposed of.

The selection of a treatment method for PFAS removal by a municipal water provider involves several considerations. For example, it’s important to balance the cost of implementing and maintaining a treatment system. In addition, some treatment methods, like RO, may remove beneficial minerals along with contaminants and might necessitate adding minerals back into the treated water.

Public water systems across the country have until 2027 to begin monitoring regulated PFAS compounds. This allows them time to plan and budget for potential treatment upgrades if needed. If a water system exceeds the standards, they will have an additional time to implement solutions to bring their PFAS levels down. 

There is currently more than $1 billion available through the federal Inflation Reduction Act to treat PFAS.  

What happens to the PFAS once removed from drinking water?

Regardless of the treatment method used, the process of PFAS removal generates a concentrated waste stream containing PFAS. Traditional wastewater treatment processes, like those focused on removing bacteria and organic matter, are largely ineffective at eliminating PFAS. 

Several technologies show promise for PFAS removal in wastewater, but they are still under development. For example, similar to municipal water treatment, advanced GAC or ion exchange resins specifically designed for PFAS capture are being explored. 

In addition, high-pressure membrane filtration systems like nanofiltration or RO can be effective, but they can be expensive and generate significant PFAS-laden solid or liquid brine wastes. High-temperature incineration can destroy PFAS compounds, but this method raises concerns about air pollution and significant energy inputs.

Treating PFAS in wastewater is an ongoing challenge that requires ongoing research and development of new technologies. 

Can you remove PFAS from drinking water at home?

In short, yes. Readily available water filtration systems can remove most PFAS from home drinking water that has not already been municipally treated. 

Carbon block filters, RO and some ion exchange resin systems that are certified to remove PFAS will carry a “NSF/ANSI 53” or “NSF/ANSI 58” label. RO systems are considered the most effective at removing a variety of contaminants, including PFAS. Some types of activated carbon filters, particularly those designed specifically for PFAS removal, can be effective. 

It is critical that once in use, these systems also be maintained with new, regularly scheduled filter changes. The EPA offers more information on what to look for in home systems.

The effectiveness of different methods for removing PFAS at home can vary depending on the specific type of PFAS and the level of contamination in your water. No single home filtration method is guaranteed to completely eliminate PFAS.

If you're concerned about PFAS in your drinking water, it's also recommended that you have your water tested by a certified laboratory. This can help you determine the level of PFAS contamination and choose the most appropriate treatment option.

What is the health benefit of this new regulation?

The new EPA regulation provides a critical step in addressing PFAS contamination in drinking water. Reducing PFAS in drinking water offers a range of potential health benefits, both for individuals and the population as a whole, including lower cancer risk, improved immune function, reduced risk of birth complications, lower cholesterol levels and developmental advantages in children.

While this rule only targets a specific set of PFAS compounds, it represents significant progress in protecting public health. The EPA estimates the new PFAS regulation will yield significant public health benefits over time, including the prevention of thousands of deaths and reduced instances of serious illness.

What are ASU researchers doing to address PFAS in drinking water?

ASU researchers, including Paul Westerhoff, a pillar lead for the Arizona Water Innovation Initiative (AWII), a multi-year partnership with the state led by Arizona State University’s Julie Ann Wrigley Global Futures Laboratory in collaboration with the Ira A. Fulton Schools of Engineering, have been working for many years on PFAS related issues. 

For example, several water treatment experts have demonstrated use of commercially available technologies to remove PFAS from groundwater that is used as drinking water in Arizona. Westerhoff and his team have been working with water managers in the southern Arizona area to address PFAS in local groundwater.

In addition, they have developed lab-scale testing protocols known as rapid small scale column tests. These tests allow for quicker evaluation of GAC treatments and represent a more than 100 times cost savings that can help municipal water providers evaluate efficacy of PFAS treatment technology.

Based on this work, Westerhoff, Pierre Herckes and Treavor Boyer have received three federal grants to understand and measure what happens to PFAS on GAC after it absorbs PFAS and before it goes to a landfill. This approach has the potential to enable reuse of GAC after thermal regeneration and represents a 2-4 times cost savings over purchasing new GAC.

Researchers are also working with private sector consultants to identify the best adsorbent to remove PFAS from impacted groundwater, estimate lifecycle costs and design the configuration of GAC treatment processes. 

Other fundamental research projects are underway at ASU, led by Bruce Rittman and Sergio Garcia Segura, to develop, patent and create start-up companies for new technologies to destroy PFAS. However, it will likely take several years before these technologies' efficacy and costs are well understood. Until then, processes like GAC or ion exchange are likely to be used.

This new drinking water regulation represents a significant step toward protecting public health. However, it only addresses six specific PFAS compounds, and continued research and monitoring are needed.

Although this new rule may be challenging to contend with, it has important implications for improving human health and well-being and leading to medical system cost-savings.

Related reading

• Removing 'forever' chemicals from drinking water | ASU News
• Overcoming the downside of 'forever chemicals' | ASU News
• PFAS Resources | Arizona Department of Environmental Quality

• Final PFAS National Primary Drinking Water Regulation | US EPA