PFAS in Drinking Water: Health Risks and How to Reduce Exposure

Most families think about drinking water in simple terms: Does it look clear? Does it smell normal? Does it taste fine?

But some of the most concerning drinking water contaminants do not change the way water looks, smells, or tastes. PFAS are one of them.

PFAS in drinking water have become a major public health concern in the United States because these chemicals can persist in the environment, accumulate in the body over time, and have been linked in scientific studies to several health effects. PFAS are often called “forever chemicals” because many of them do not break down easily in the environment. The U.S. Environmental Protection Agency says PFAS are widely used, long-lasting chemicals, and that exposure to certain PFAS may be linked to harmful health effects. (US EPA)

For families, the difficult part is that PFAS exposure is not obvious. You cannot see PFAS in a glass of water. You cannot smell them. You may not know whether your water has them unless your water utility reports results or you test your water directly.

This guide explains what PFAS are, how they enter drinking water, which health risks researchers are most concerned about, and how to reduce exposure at home.

What Are PFAS?

PFAS stands for per- and polyfluoroalkyl substances. This is a large class of synthetic chemicals used for decades in industrial processes and consumer products because they resist heat, oil, grease, stains, and water.

PFAS have been used in products such as:

• Nonstick cookware
• Stain-resistant carpets and upholstery
• Water-resistant clothing
• Grease-resistant food packaging
• Firefighting foam
• Industrial coatings
• Some cosmetics and personal care products
• Certain cleaning and protective products

Not all PFAS are the same. Some of the most discussed compounds include:

• PFOA
• PFOS
• PFHxS
• PFNA
• PFBS
• HFPO-DA, also known as GenX chemicals

PFOA and PFOS are among the best-studied PFAS. Although some older PFAS have been phased out of many U.S. manufacturing uses, they remain in the environment and can still be found in water, soil, wildlife, and people.

The National Institute of Environmental Health Sciences notes that PFAS are a concern because they are widespread, persistent, and have been found in the blood and urine of people. (NIEHS)

How Do PFAS Get Into Drinking Water?

PFAS can enter drinking water when they contaminate groundwater, rivers, lakes, reservoirs, or private wells. Once released, many PFAS can travel through soil and water and remain there for long periods.

Common sources include:

• Industrial sites
• Chemical manufacturing facilities
• Airports and military bases where firefighting foam was used
• Landfills
• Wastewater treatment discharge
• Biosolids applied to land
• Contaminated soil or groundwater near historic PFAS use
• Consumer product waste entering the environment

Drinking water contamination can affect both public water systems and private wells. Public utilities are subject to testing and reporting requirements, while private well owners are typically responsible for testing their own water.

This distinction matters. If you are on municipal water, your utility may provide annual water quality reports and PFAS updates. If you use a private well, you may need to arrange PFAS testing yourself.

Why PFAS in Drinking Water Matters

PFAS exposure can happen through multiple routes, including food, dust, consumer products, and drinking water. But drinking water can be a major exposure source in contaminated communities because it is used every day for drinking, cooking, infant formula, coffee, tea, and ice.

Children may be especially vulnerable because they drink more water, eat more food, and breathe more air per pound of body weight than adults. The EPA also notes that young children may have additional PFAS exposure from carpets, household dust, toys, and cleaning products because they crawl on floors and put things in their mouths. (US EPA)

The concern is not usually a single glass of water. The concern is repeated exposure over months or years.

PFAS can remain in the body for a long time. Some PFAS have biological half-lives measured in years, meaning it can take a long time for blood levels to decrease after exposure is reduced. That is why prevention and reduction matter.

Health Risks Linked to PFAS Exposure

PFAS science is still evolving. Researchers are studying different PFAS compounds, exposure levels, and health outcomes. Not every PFAS has the same evidence base, and not every person exposed will develop health problems.

Still, major public health agencies have identified several areas of concern.

The EPA states that current scientific research suggests exposure to certain PFAS may lead to reproductive effects, developmental effects, or delays in children, increased risk of some cancers, reduced immune response, hormone interference, increased cholesterol levels, and liver effects. (US EPA)

1. Immune System Effects

One of the most important concerns is immune function. Some studies have found associations between PFAS exposure and reduced antibody response to vaccines, especially in children.

This matters because the immune system is how the body responds to infections and vaccines. Reduced immune response does not mean a child has no protection, but it can indicate that PFAS may interfere with normal immune signaling.

For families, this is one reason PFAS exposure is not just an abstract chemical issue. It may affect systems that are especially important during childhood.

2. Developmental and Pregnancy-Related Concerns

PFAS exposure has been studied in relation to pregnancy outcomes and child development. Some research has linked certain PFAS with lower birth weight, developmental effects, and possible changes in growth or behavior.

The CDC/ATSDR has noted that some studies in humans suggest certain PFAS may affect the developing fetus and child, including possible changes in growth, learning, and behavior. (New York State Department of Health)

Pregnant people, infants, and young children are often considered priority groups for reducing exposure because early development can be more sensitive to environmental chemicals.

3. Cholesterol Changes

PFAS exposure has been associated with increased cholesterol levels in several studies. Cholesterol is not something a person can feel day to day, which makes this risk easy to overlook.

Elevated cholesterol can influence long-term cardiovascular risk, especially when combined with other factors such as family history, diet, inactivity, smoking, diabetes, or high blood pressure.

4. Liver Effects

The liver helps process chemicals, regulate metabolism, and manage detoxification pathways. Some PFAS have been associated with changes in liver enzymes or liver-related markers.

This does not mean PFAS exposure automatically causes liver disease. It means PFAS may add to the body’s chemical burden and should be reduced when practical, especially when drinking water levels are elevated.

5. Hormonal and Thyroid Concerns

Some PFAS may interfere with hormone systems. Thyroid hormones are especially important for metabolism, energy, growth, pregnancy, and child development.

Evidence varies by PFAS compound and study design, but thyroid-related effects remain an area of active concern and research.

6. Cancer Risk

Some PFAS have been associated with increased risk of certain cancers, including kidney and testicular cancer. The EPA includes an increased risk of some cancers among potential health effects from certain PFAS exposure. (US EPA)

Cancer risk is influenced by many factors, including genetics, age, smoking, occupational exposures, diet, and total environmental exposure. PFAS should be viewed as one potential contributor among many, but one that families can often take steps to reduce.

Current EPA Drinking Water Standards for PFAS

In April 2024, the EPA finalized the first national drinking water regulation for several PFAS. The rule sets legally enforceable Maximum Contaminant Levels, or MCLs, for specific PFAS in public drinking water systems. The EPA’s technical overview lists final MCLs of 4.0 parts per trillion for PFOA, 4.0 parts per trillion for PFOS, and 10 parts per trillion for PFHxS, PFNA, and HFPO-DA/GenX chemicals, along with a Hazard Index limit for mixtures of certain PFAS. (US EPA)

A few important points:

• These limits apply to regulated public water systems, not directly to private wells.
• “Parts per trillion” is an extremely small concentration, reflecting concern about low-level long-term exposure.
• Utilities need time, infrastructure, and funding to monitor and reduce PFAS.
• Federal PFAS policy has been in flux, with recent reporting indicating the EPA may revisit or delay parts of the rule while maintaining limits for PFOA and PFOS. (AP News)

For homeowners, the practical takeaway is simple: PFAS are now treated as serious drinking water contaminants at the national level, and families should know whether their water has been tested.

How to Know If Your Drinking Water Has PFAS

You cannot identify PFAS by taste, smell, or appearance. Testing or official reporting is needed.

If You Use Public Water

Start with your water utility.

Look for:

• Annual Consumer Confidence Reports
• PFAS-specific testing updates
• Notices about treatment changes
• State environmental agency PFAS maps or reports
• Local health department guidance

Some utilities already test for PFAS and publish results. Others may be in the process of monitoring or planning treatment upgrades.

If You Use a Private Well

Private well owners should be more proactive. Public water rules generally do not cover private wells, and PFAS contamination can vary from one property to another.

Consider PFAS testing if:

• You live near an airport, military base, landfill, industrial site, or firefighting training area
• Nearby public water systems have detected PFAS
• Your state or county has identified PFAS contamination in the area
• You rely on well water for infant formula or pregnancy
• You want a clearer picture of the home drinking water risk

Use a lab that follows appropriate PFAS testing methods. PFAS sampling can be sensitive to contamination, so follow the lab’s instructions carefully.

How to Reduce PFAS Exposure From Drinking Water

The best PFAS reduction strategy depends on your water source, PFAS levels, budget, household needs, and whether you rent or own.

The EPA identifies activated carbon, ion exchange resins, and high-pressure membranes such as reverse osmosis as technologies that can reduce PFAS in drinking water. (US EPA)

1. Use a Certified PFAS-Reducing Water Filter

Not every water filter removes PFAS. A basic pitcher filter may improve taste or reduce chlorine, but may not meaningfully reduce PFAS unless it is specifically certified for that purpose.

The EPA says point-of-use filters can be a relatively inexpensive treatment for reducing PFAS at a single faucet or fixture and recommends checking for certified filters. (US EPA)

Look for filters certified by reputable third-party organizations, such as NSF, WQA, IAPMO, CSA, or UL, for PFAS reduction claims.

Common options include:

• Activated carbon filters
• Reverse osmosis systems
• Ion exchange systems

NSF notes that current NSF/ANSI Standards 53 and 58 were updated to address PFAS reduction, including standards for activated carbon and reverse osmosis systems. (NSF)

2. Consider Reverse Osmosis for Drinking and Cooking Water

Reverse osmosis, often called RO, can be one of the strongest home options for reducing PFAS, especially at a kitchen sink. RO systems use pressure to push water through a membrane that removes many dissolved contaminants.

Pros:

• Strong reduction potential for many PFAS
• Useful for drinking and cooking water
• Often installed under the sink
• Can also reduce other contaminants, depending on the system

Cons:

• Higher upfront cost than basic filters
• Requires maintenance and filter changes
• Produces wastewater
• May reduce beneficial minerals along with contaminants
• Performance depends on system quality and installation

For families with known PFAS contamination, RO is often worth considering for the main drinking water tap.

3. Use Activated Carbon Filters Correctly

Granular activated carbon can reduce certain PFAS by adsorbing chemicals as water passes through the filter. Performance depends on the PFAS type, filter design, contact time, water quality, and how often the filter is replaced.

Activated carbon may be available as:

• Pitcher filters
• Faucet-mounted filters
• Countertop systems
• Under-sink filters
• Whole-house systems

For PFAS, certification matters. So does maintenance. A filter that is not replaced on schedule may stop performing well.

4. Do Not Boil Water to Remove PFAS

Boiling water does not remove PFAS. In fact, because boiling reduces water volume, it may concentrate some contaminants that remain behind.

Boiling is useful for certain microbes during boil-water advisories, but it is not a PFAS solution.

5. Use Filtered Water for Infant Formula If PFAS Is a Concern

If PFAS levels are elevated in your water and you prepare infant formula, filtered or alternative water may reduce exposure. Infants drink more water relative to body weight than adults, and early development is a sensitive period.

Parents should follow pediatric guidance for infant feeding and speak with a healthcare professional or local health department when contamination is known or suspected.

6. Maintain Filters Exactly as Directed

PFAS-reducing filters are not “set it and forget it” devices.

Follow the manufacturer’s instructions for:

• Filter replacement timing
• Flow rate
• Installation
• Flushing
• Water volume capacity
• Maintenance
• Certification claims

A filter should be matched to the contaminants found in your water. If your concern is PFAS, do not assume a general “clean water” claim is enough.

Should You Use Bottled Water for PFAS?

Bottled water may be useful as a temporary option in some high-contamination situations, but it is not always the best long-term solution.

Considerations include:

• Bottled water can be expensive
• Plastic waste adds up
• Bottled water quality varies
• Some bottled water may still contain PFAS unless tested or treated
• Home filtration may be more practical over time

If your local health department recommends bottled water because of contamination, follow that guidance. Otherwise, certified home filtration may be a more sustainable long-term approach.

Other Ways to Reduce PFAS Exposure at Home

Drinking water may be a major exposure source, but PFAS can also come from food, dust, and consumer products.

You can reduce overall exposure by:

• Checking whether your water has been tested
• Using certified filtration when needed
• Reducing the use of stain-resistant sprays and treatments
• Limiting grease-resistant takeout packaging when practical
• Vacuuming with a HEPA filter to reduce household dust
• Wet-mopping floors
• Washing hands before eating, especially for young children
• Avoiding products marketed as stain-proof, water-proof, or grease-proof unless needed
• Replacing worn nonstick cookware when coatings are damaged
• Reviewing cosmetics or personal care products for PFAS-related ingredients when possible

You do not need to eliminate every possible source overnight. Start with the biggest, most repeatable exposure routes: water, food contact, dust, and products used daily.

PFAS and Families: Who Should Be Most Careful?

Everyone benefits from reducing unnecessary PFAS exposure, but some groups may have more reason to prioritize testing and filtration.

These include:

• Pregnant people
• People planning a pregnancy
• Infants
• Young children
• People with immune concerns
• People with kidney disease or liver concerns
• Households using private wells
• Families near known contamination sites
• Communities with detected PFAS in public water

The goal is not fear. The goal is informed action.

What to Do If Your Water Tests Positive for PFAS

A positive PFAS test does not automatically mean your water is unsafe in the same way a bacterial contamination event might be urgent. PFAS risk is usually about the long-term exposure level and duration.

Still, you should take it seriously.

Step 1: Compare Results to Current Guidance

Review the detected PFAS compounds and concentrations. Compare them with EPA limits, state guidance, and local health department recommendations.

Step 2: Identify Your Main Uses

Ask:

• Do you drink this water daily?
• Do you cook with it?
• Do you use it for infant formula?
• Are pregnant people or young children in the home?
• Is the source public water or a private well?

Step 3: Choose a Reduction Strategy

Depending on the results, you may consider:

• Certified point-of-use filtration
• Reverse osmosis at the kitchen sink
• Alternative water for infants or pregnancy
• Whole-house treatment in some cases
• Retesting after treatment installation

Step 4: Keep Records

Save:

• Lab reports
• Filter certifications
• Maintenance dates
• Utility notices
• Local health advisories
• Retesting results

These records help you make better decisions over time.

How Nestwell Can Help Families Think About PFAS

PFAS in drinking water is part of a broader home health question: What invisible environmental risks might be affecting your household, and what should you do next?

Most families do not need more vague worry. They need a clearer plan.

Nestwell helps families move from uncertainty to action by connecting home health concerns—such as drinking water quality, indoor air quality, mold risk, and environmental exposures—to practical next steps. For PFAS concerns, that may include understanding whether your water should be tested, what the results mean, and which exposure-reduction options make sense for your household.

Clean water is not just a utility issue. It is a family health issue.

FAQ: PFAS in Drinking Water

What are PFAS in drinking water?

PFAS in drinking water are synthetic chemicals that can contaminate groundwater, rivers, reservoirs, private wells, and public water systems. They are often called “forever chemicals” because many do not break down easily in the environment.

Is PFAS in drinking water dangerous?

PFAS in drinking water may increase health risks when exposure is repeated over time. Certain PFAS have been linked to immune effects, increased cholesterol, liver effects, developmental concerns, reproductive effects, thyroid disruption, and some cancers.

Can you taste or smell PFAS in water?

No. PFAS generally cannot be seen, smelled, or tasted in drinking water. The only reliable way to know whether water contains PFAS is through water utility testing, state reporting, or laboratory testing.

Does boiling water remove PFAS?

No. Boiling water does not remove PFAS. Boiling may reduce the amount of water while leaving PFAS behind, which can concentrate contaminants. PFAS reduction usually requires certified filtration such as activated carbon, ion exchange, or reverse osmosis.

What water filter removes PFAS?

Filters certified for PFAS reduction may include activated carbon systems, reverse osmosis systems, and ion exchange systems. Look for third-party certification from organizations such as NSF, WQA, IAPMO, CSA, or UL, and confirm the filter is certified for PFAS reduction specifically.

Should private well owners test for PFAS?

Private well owners should consider PFAS testing if they live near an airport, military base, landfill, industrial site, firefighting training area, or known PFAS contamination zone. Private wells are not usually covered by public water testing rules.

Are children more vulnerable to PFAS exposure?

Children may be more vulnerable because they are still developing and often drink more water per pound of body weight than adults. Young children may also have additional exposure through dust, carpets, toys, and hand-to-mouth behavior.

How can I reduce PFAS exposure at home?

You can reduce PFAS exposure by testing drinking water when appropriate, using a certified PFAS-reducing filter, maintaining filters properly, reducing dust, limiting stain-resistant or grease-resistant products, and following local health department guidance if contamination is known.

Conclusion: PFAS Risk Is Invisible, But Not Unmanageable

PFAS in drinking water can feel overwhelming because the chemicals are invisible, persistent, and surrounded by evolving science. But families do not have to treat PFAS as an unsolvable problem.

The most practical path is clear: find out whether your water has been tested, understand your risk, use certified treatment when needed, and reduce repeated exposure where you can.

For many households, the biggest step is simply moving from assumption to evidence.

Nestwell helps families better understand home environmental health, including water quality concerns like PFAS, so they can make informed decisions with less guesswork and more confidence.