PFAS in Drinking Water: What You Need to Know
PFAS & Forever Chemicals
PFAS in Drinking Water: What You Need to Know
PFAS contamination has been found in at least 45% of U.S. tap water. The EPA now enforces limits on the two most common types, and your utility may not be in compliance for years. This guide covers what PFAS are, how they get into your water, what the health risks look like, how to test for them, and what actually removes them. Written from 30+ years of water treatment experience.
The Short Answer
PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals that do not break down in the environment or in your body. Often called "forever chemicals," they have been linked to cancer, thyroid disease, immune suppression, and reproductive harm. The EPA set enforceable limits for PFOA and PFOS at 4 parts per trillion (ppt) in 2024, but public water systems have until 2031 to comply. Private wells have no monitoring requirement at all.
Three proven residential technologies remove PFAS from drinking water:
- Activated carbon filtration (GAC): Effective for long-chain PFAS like PFOA and PFOS. Whole-house systems with large carbon beds provide the contact time needed for meaningful reduction. Browse whole-house carbon filters.
- Ion exchange (dedicated PFAS media): ResinTech SIR-110-HP resin targets PFAS specifically, including short-chain compounds that carbon may miss. See the PFAS Removal System ($1,695).
- Reverse osmosis (RO): Removes 90% to 99%+ of all PFAS types at the kitchen sink. Best as a point-of-use drinking water system ($595).
For a detailed comparison of filters, product recommendations, and sizing guidance, read: PFAS Water Filter: How to Remove Forever Chemicals from Your Water. If you have test results and want a personalized recommendation, call Aidan at 800-460-5810.
What PFAS Protection Do You Need?
Answer 4 quick questions for a personalized recommendation.
What Are PFAS ("Forever Chemicals")?
PFAS stands for per- and polyfluoroalkyl substances. This is a family of over 15,000 synthetic chemicals that have been manufactured and used worldwide since the 1940s. The defining characteristic of PFAS is a carbon-fluorine bond, one of the strongest chemical bonds in nature. That bond is what makes them useful in manufacturing (resistance to water, grease, and heat) and what makes them dangerous in the environment: they do not break down.
In practical terms, PFAS are chemicals you have encountered in nonstick cookware (Teflon), stain-resistant fabrics (Scotchgard), food packaging, waterproof clothing, and firefighting foam (AFFF). For decades, manufacturers discharged PFAS into waterways and landfills. Those chemicals migrated into groundwater, surface water, and eventually into drinking water supplies. Because they do not degrade, every molecule of PFAS ever released into the environment is still there.
The term "forever chemicals" is not a marketing label. It is a factual description: PFAS persist in the environment indefinitely and accumulate in the human body over time. A 2023 USGS study estimated that at least 45% of U.S. tap water has one or more detectable PFAS compounds (USGS, 2023).
Why "Parts Per Trillion" Matters
The EPA's PFAS limit of 4 parts per trillion is extraordinarily small. To put it in perspective: 4 parts per trillion is equivalent to about 4 drops of water in 20 Olympic-sized swimming pools. The fact that the EPA set limits this low reflects how toxic these compounds are at very small concentrations. Standard water filters designed for chlorine or sediment do not operate at this level of precision.
The Most Common Types of PFAS
While there are thousands of PFAS compounds, only a handful are commonly detected in drinking water and regulated by the EPA. Understanding the differences matters because each type responds differently to filtration technologies.
| PFAS Type | Full Name | Chain Length | Primary Sources | EPA MCL (2024) |
|---|---|---|---|---|
| PFOA | Perfluorooctanoic acid | Long-chain (C8) | Teflon manufacturing, industrial discharge | 4 ppt |
| PFOS | Perfluorooctane sulfonic acid | Long-chain (C8) | Firefighting foam (AFFF), Scotchgard | 4 ppt |
| PFHxS | Perfluorohexane sulfonic acid | Short-chain (C6) | Firefighting foam, industrial processes | 10 ppt* |
| PFNA | Perfluorononanoic acid | Long-chain (C9) | Chemical manufacturing | 10 ppt* |
| GenX (HFPO-DA) | Hexafluoropropylene oxide dimer acid | Short-chain | Replacement for PFOA in manufacturing | 10 ppt* |
| PFBS | Perfluorobutane sulfonic acid | Short-chain (C4) | Industrial processes, replacement for PFOS | 2,000 ppt* |
*MCLs for PFHxS, PFNA, GenX, and PFBS were part of the EPA's April 2024 rule. In May 2025, the EPA announced plans to reconsider these limits while keeping the PFOA and PFOS limits at 4 ppt. Source: EPA PFAS Drinking Water Regulation
Long-Chain vs Short-Chain: Why It Matters for Filtration
Long-chain PFAS (PFOA, PFOS, PFNA) have longer carbon chains and are more readily adsorbed by activated carbon. This makes them easier to remove with carbon filtration systems. Short-chain PFAS (PFHxS, PFBS, GenX) are smaller molecules that pass through carbon beds more quickly. For comprehensive removal of all PFAS types, including short-chain compounds, reverse osmosis or specialized ion exchange resin is more reliable.
How PFAS Get Into Your Drinking Water
PFAS contamination is not random. These chemicals follow specific pathways from their source into drinking water supplies. Understanding these pathways helps you assess your own risk.
Conventional Water Treatment Does Not Remove PFAS
Standard municipal water treatment (coagulation, sedimentation, chlorination) was not designed for PFAS and does not remove them. Your city may be treating your water for bacteria, chlorine, and turbidity while PFAS pass straight through to your tap. This is why the EPA's new regulations are requiring water systems to add specialized PFAS treatment, a process that may take years to complete.
EPA PFAS Regulations: The Federal Limits
In April 2024, the EPA finalized the first-ever National Primary Drinking Water Regulation for PFAS. This was a landmark rule: it made PFAS legally enforceable contaminants for the first time in U.S. history.
PFOA
Maximum Contaminant Level
4 ppt
The strictest drinking water standard the EPA has ever set for any contaminant. Enforceable and legally binding for public water systems.
PFOS
Maximum Contaminant Level
4 ppt
The most commonly detected PFAS in U.S. drinking water, primarily from decades of firefighting foam use at military and civilian facilities.
Source: EPA PFAS Drinking Water Regulation
Regulatory Timeline
The Gap Between Detection and Compliance
Public water systems have until 2031 to comply with the 4 ppt limit. That means even if your utility detects PFAS above the legal limit today, they are not required to fix it for years. During this window, a home filtration system is the only way to reduce your exposure now.
State-Level Standards
Several states have set their own PFAS limits that are stricter than or predate the federal rule:
- New Jersey: 14 ppt for PFOA, 13 ppt for PFOS (set in 2020, among the first state-level limits)
- Massachusetts: 20 ppt total for six PFAS compounds combined
- Michigan: 8 ppt for PFOA, 16 ppt for PFOS (Michigan has identified more contamination sites than most states)
- New Hampshire: 12 ppt for PFOA, 15 ppt for PFOS
- Vermont: 20 ppt total for five PFAS compounds
If your state has stricter limits, your utility must meet whichever standard is more protective. But remember: these limits apply only to public water systems. Private wells remain unregulated.
PFAS Health Effects: What the Science Shows
PFAS health effects have been studied extensively over the past two decades. The EPA, CDC/ATSDR, and National Academies of Sciences have all reviewed the evidence. The EPA set its limits at 4 parts per trillion specifically because research shows harm at very low concentrations with chronic exposure. For a detailed breakdown of each body system affected, see our PFAS Health Effects guide.
Known and Probable Health Effects
The following effects have been associated with PFAS exposure in peer-reviewed human and animal studies:
- Cancer: Kidney cancer, testicular cancer, and elevated risk of bladder, thyroid, and prostate cancers. PFOA is classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC). A 2026 USC Keck School of Medicine study linked PFAS in drinking water to elevated rates of rare cancers (USC Keck, 2026).
- Thyroid disease: PFAS disrupt thyroid hormone production. Studies show increased rates of hypothyroidism in exposed populations.
- Immune system suppression: Reduced vaccine antibody response in both children and adults. The National Academies identified decreased antibody response as a health effect with sufficient evidence (National Academies, 2022).
- Reproductive harm: Reduced fertility, pregnancy-induced hypertension/preeclampsia, and lower birth weight.
- Elevated cholesterol: PFAS exposure increases total cholesterol and LDL cholesterol levels.
- Liver damage: Elevated liver enzymes and increased risk of liver disease with chronic exposure.
Sources: EPA PFAS Health Risks, CDC/ATSDR PFAS
PFAS Risk by Concentration
PFAS Concentration Risk Spectrum (PFOA/PFOS)
| PFAS Level (ppt) | Classification | Health Concern | Recommended Action |
|---|---|---|---|
| Non-detect (<2 ppt) | Below detection limit | No known concern at current scientific understanding | No PFAS-specific treatment needed |
| 2 to 4 ppt | Detectable, below MCL | Below the federal limit, but some health organizations advocate for lower thresholds | Consider treatment for pregnant women, infants, or immunocompromised individuals |
| 4 to 20 ppt | Above EPA MCL | Exceeds the federal limit. Chronic exposure at these levels is linked to the health effects above | Treatment recommended. Carbon filtration and/or reverse osmosis |
| Above 20 ppt | Significantly elevated | Well above the federal limit. Higher concentrations increase risk, especially for vulnerable populations | Treatment essential. Dedicated PFAS system or carbon + RO combination. Call Aidan at 800-460-5810 |
Who Is Most Vulnerable
- Pregnant women and developing fetuses: PFAS cross the placenta. Exposure during pregnancy is linked to preeclampsia, low birth weight, and developmental effects.
- Infants and young children: Higher PFAS concentrations relative to body weight. Studies show reduced vaccine effectiveness in PFAS-exposed children.
- People with chronic health conditions: Those with thyroid disease, high cholesterol, liver disease, or compromised immune systems may be more sensitive to additional PFAS exposure.
- Military families: AFFF firefighting foam use at military installations is one of the largest sources of PFAS groundwater contamination in the U.S.
How to Test Your Water for PFAS
PFAS testing is not included in standard well water panels or routine municipal water quality reports. It requires a specialized laboratory test using EPA-approved methods. Here is how to find out if PFAS are in your water. For a complete walkthrough of testing options, costs, and how to read your results, see our PFAS Testing Guide.
If You Are on City Water
Start with free resources before paying for your own test:
- Consumer Confidence Report (CCR): Your utility publishes an annual water quality report, usually available online. Search "[your utility name] water quality report." Starting in 2027, PFAS monitoring results will be included.
- EPA's UCMR 5 data: The EPA's Fifth Unregulated Contaminant Monitoring Rule required large water systems to test for PFAS. Results are publicly searchable by location.
- EWG PFAS contamination map: The Environmental Working Group maintains an interactive map of known PFAS contamination sites.
If You Are on Well Water
No government agency tests private wells for PFAS. You are responsible for your own testing. For general well water testing guidance, see our guide to testing well water.
- Find a certified lab: Look for a laboratory certified for EPA Method 533 or 537.1. National mail-in options include SimpleLab (Tap Score), Eurofins, and ALS Environmental.
- Order a test kit: The lab sends collection bottles and instructions. A comprehensive PFAS panel typically costs $200 to $400.
- Collect correctly: PFAS testing is sensitive to contamination. Do not use Teflon-coated containers. Run the tap for 2 to 3 minutes before collecting.
- Wait for results: Turnaround is typically 2 to 4 weeks.
- Read your results: Compare PFOA and PFOS levels to the EPA MCL of 4 ppt each. If either exceeds 4 ppt, treatment is recommended.
Send Your Results to Aidan
Once you have test results, email them to support@midatlanticwater.net or call Aidan at 800-460-5810. He will review your specific levels and recommend the right system. No charge for the consultation.
How to Remove PFAS from Water
Not every water filter removes PFAS. The chemicals are invisible, odorless, and present at parts-per-trillion concentrations. Standard sediment filters, water softeners, and basic pitcher filters were not designed for this. Three technologies have strong evidence for residential PFAS removal. For a detailed comparison with specific product recommendations, read our PFAS Water Filter guide, or compare every certified system side by side in our PFAS water filters collection.
Activated Carbon (GAC)
Best for: Long-chain PFAS (PFOA, PFOS). Treats every tap.
Also removes: Chlorine, VOCs, taste/odor
Limitation: Short-chain PFAS break through faster
Ion Exchange (PFAS Resin)
Best for: All PFAS types, including short-chain
How it works: ResinTech SIR-110-HP targets PFAS molecules specifically
Advantage: Engineered for PFAS, not general filtration
Reverse Osmosis (RO)
Best for: Drinking/cooking water. Removes 90-99%+ of all PFAS types
Model: Pure-75 RO ($595), 75 gallons/day
Limitation: Under-sink only, not whole house
What Does NOT Remove PFAS
- Boiling: Does not remove PFAS. Actually concentrates them by evaporating water while the chemicals remain.
- Water softeners: Ion exchange resin in softeners targets calcium and magnesium, not PFAS molecules.
- Sediment filters: Remove particles. PFAS are dissolved chemicals, not particles.
- UV disinfection: Kills bacteria and viruses. Has no effect on dissolved chemicals.
- Standard municipal treatment: Chlorination, coagulation, and sedimentation do not remove PFAS.
The Recommended Combination for Maximum Protection
For the most comprehensive residential PFAS protection:
- Whole-house treatment (point of entry): Either a dedicated PFAS removal system ($1,695) or a 2.5 CF carbon filter ($1,695) to reduce PFAS at every tap.
- Under-sink RO (point of use): A Pure-75 reverse osmosis system ($595) as the final barrier for drinking and cooking water.
Both systems are DIY-installable with standard plumbing connections. Call Aidan at 800-460-5810 with your water test results for help choosing the right combination and sizes for your home.
Where PFAS Contamination Is Worst
PFAS contamination is a nationwide problem. The Environmental Working Group has documented over 9,700 contamination sites across all 50 states. EPA monitoring data shows that over 1,050 public water systems serving at least 52 million Americans have reported PFAS levels above the new federal limits (EWG, 2026). For a state-by-state breakdown with contamination data, regulations, and risk levels, see our PFAS Contamination by State guide.
Northeast
High contamination density near military bases and industrial sites. New Jersey, Massachusetts, and New Hampshire set some of the earliest and strictest state PFAS limits.
Southeast
Major contamination near military bases and chemical plants. North Carolina's Cape Fear River basin is a high-profile GenX case. Coal ash sites have also contributed PFAS to groundwater.
Great Lakes Region
Michigan has identified more PFAS contamination sites than nearly any other state. Major sources include manufacturing facilities and military installations.
West Coast
California has extensive monitoring and comprehensive state regulations. Contamination concentrates around military bases, airports, and industrial zones.
Common Contamination Sources Near You
- Military bases (active and closed): AFFF firefighting foam training has contaminated groundwater at hundreds of installations.
- Commercial airports: Fire training activities using AFFF contaminate surrounding soil and groundwater.
- Industrial manufacturing: Facilities that manufactured or used fluoropolymers, electronics, or textiles.
- Landfills: PFAS from consumer products leach into groundwater.
- Wastewater treatment plants: Treated wastewater carries PFAS downstream into rivers and reservoirs.
Use the EWG PFAS Contamination Map to check for known sites near your home.
Well Water vs City Water: Different PFAS Risks
Whether you are on municipal water or a private well changes your PFAS situation significantly. Neither source is inherently safer than the other, but the regulatory landscape is very different. For a broader comparison of these water sources, see our Well Water vs City Water guide.
| Factor | City / Municipal Water | Private Well Water |
|---|---|---|
| PFAS monitoring | Required under federal law by 2027 | No requirement. You must test yourself. |
| Treatment requirement | Must meet 4 ppt MCL by 2031 | No requirement. Your responsibility entirely. |
| Contamination source | Surface water intakes, industrial discharge upstream, wastewater effluent | Groundwater migration from military bases, industrial sites, landfills, biosolids |
| Transparency | Results will be publicly reported starting 2027 | No one knows your PFAS level until you pay for a test |
| Other contaminants | Chlorine/chloramines (disinfection byproducts). See chlorine health effects | Potentially iron, sulfur, bacteria, low pH. See well water filtration guide |
| Best PFAS protection | Carbon filter or PFAS system + RO for drinking water | Same, plus regular testing since no one monitors for you |
Well Water Owners: No One Is Testing for You
The EPA's PFAS rules apply only to public water systems. If you have a private well, no federal, state, or local agency is required to test your water for PFAS. The responsibility falls entirely on you. This is especially important if you live within 5 miles of a military base, airport, industrial park, or landfill.
A homeowner in North Carolina contacted us about PFAS concerns near a coal ash site. Local companies were quoting thousands of dollars for treatment systems. We recommended getting a proper water test first to determine what was actually in the water before buying anything. That is always the right first step.
Frequently Asked Questions
Does boiling water remove PFAS?
No. Boiling water does not remove PFAS. In fact, boiling concentrates PFAS because the water evaporates while the chemicals remain behind. You need a physical removal process: activated carbon adsorption, ion exchange, or reverse osmosis membrane filtration.
Does a Brita filter remove PFAS?
Some Brita filters provide partial reduction of PFOA and PFOS, but performance varies by model. Standard pitcher filters have very limited carbon and contact time compared to whole-house systems. Aidan's advice to a caller asking this exact question: a Brita is better than nothing, but for serious PFAS protection, a reverse osmosis system or whole-house carbon filter is what you need. If PFAS is your primary concern, look for filters certified to NSF/ANSI Standard 53 with specific PFAS claims.
Can PFAS be absorbed through the skin?
Research on dermal PFAS absorption is still developing, but early studies suggest that some PFAS compounds can be absorbed through the skin and that inhalation of PFAS-containing steam during hot showers is a potential exposure route. This is one reason a whole-house filtration system provides more comprehensive protection than a drinking water filter alone. A whole-house carbon filter or PFAS removal system treats the water going to every tap, shower, and appliance.
How much does PFAS water testing cost?
A comprehensive PFAS water test typically costs $200 to $400 through a certified laboratory. This covers analysis for multiple PFAS compounds using EPA Method 533 or 537.1. Some states offer free or subsidized PFAS testing for private well owners. Check with your state Department of Health or Environmental Quality. National mail-in labs like SimpleLab (Tap Score) offer PFAS-specific test kits you can order online.
Is well water safer than city water for PFAS?
Not necessarily. Well water may or may not contain PFAS depending on your geology, proximity to contamination sources, and aquifer characteristics. The difference is that city water will be tested and eventually treated under federal law. Well water has no such requirement. A USGS study found detectable PFAS in a significant percentage of both public supply and private well water samples. For more on this comparison, see our well water vs city water guide.
What is the best water filter for PFAS?
It depends on your situation. For drinking water only, a reverse osmosis system ($595) is the most effective single solution, removing 90% to 99%+ of all PFAS types. For whole-house protection, a dedicated PFAS removal system ($1,695) using ion exchange resin targets all PFAS types, or a whole-house carbon filter ($1,195 to $1,695) handles long-chain PFAS plus chlorine and VOCs. For comprehensive protection, combine whole-house treatment with under-sink RO. Read our full guide: PFAS Water Filter: How to Remove Forever Chemicals.
Will my water utility fix PFAS contamination?
Eventually, yes, if they exceed the legal limit. Public water systems must comply with the EPA's PFAS MCLs by 2031. But that deadline is years away, and many systems have not begun treatment installation. Until your utility achieves compliance, a home filtration system is the only way to reduce your PFAS exposure. Check your utility's latest water quality report or contact them directly about their PFAS levels and treatment timeline.
Can I install a PFAS water filter myself?
Yes. Whole-house carbon filters, PFAS removal systems, and under-sink RO systems are all designed for homeowner installation. Whole-house systems connect to your main water line with standard plumbing fittings (typically 1 inch). Under-sink RO connects to the cold water line under your kitchen sink. All systems come with installation instructions, and Aidan provides free phone support at 800-460-5810 if you need help during the install.
Are PFAS in my water if I live in a rural area?
PFAS do not respect property lines or rural boundaries. Contamination has been found in agricultural areas (from biosolids spread on fields), near small airports, near old landfills, and in areas with no obvious industrial activity. The only way to know is to test. After helping homeowners with water quality for over 30 years, the most common mistake Aidan sees is assuming rural water is clean because it looks clear and tastes fine.
How do activated carbon filters compare to the dedicated PFAS removal system?
Activated carbon (GAC) is most effective for long-chain PFAS like PFOA and PFOS, the two compounds with enforceable EPA limits. For a deep dive on how carbon works, see What Is Activated Carbon? The dedicated PFAS removal system ($1,695) uses ResinTech SIR-110-HP ion exchange resin specifically engineered for PFAS. It targets a broader range of PFAS types, including short-chain compounds that may break through carbon beds faster. If your water test shows primarily PFOA/PFOS, carbon is effective and also removes chlorine and VOCs. If short-chain PFAS are present, the dedicated system is the better choice.
About the Author: This guide was written by Aidan Walsh, owner of Mid Atlantic Water and a water treatment specialist with over 30 years of field experience. Aidan has helped thousands of homeowners diagnose and solve water quality problems across the United States. All health and safety claims in this guide are cited to EPA, CDC/ATSDR, and peer-reviewed research. For a personalized recommendation based on your water test results, call Aidan directly at 800-460-5810 or email support@midatlanticwater.net.