PFAS didn't appear in your water spontaneously. Every molecule of contamination in your drinking water traces back to a specific source: a factory, a military base, an airport, a product you used, or a decision someone made decades ago. Understanding where PFAS comes from is the first step toward understanding your personal exposure – and whether you might have legal recourse.
This guide maps the major PFAS contamination pathways, from industrial manufacturing to your kitchen pantry.
Aqueous Film-Forming Foam (AFFF) is a specialized firefighting foam designed to suppress jet fuel and petroleum fires. Developed in the 1960s by 3M for the U.S. Navy, AFFF uses PFAS as its active ingredient – the fluorinated compounds create a film that smothers flames and prevents re-ignition.
AFFF contains extraordinarily high PFAS concentrations – often measured in parts per million, not parts per trillion. When AFFF is sprayed during a fire or training exercise, it soaks into the ground and migrates into aquifers. A single training exercise can release hundreds of gallons of foam.
Now multiply that by:
The Department of Defense alone has identified over 700 installations with known or suspected AFFF contamination. Some sites show groundwater PFAS levels exceeding 100,000 parts per trillion – 25,000 times the EPA's 4 ppt limit.
Military bases: Every branch of the U.S. military used AFFF extensively. Air Force bases, naval air stations, and Army installations conducted regular firefighting training exercises that released massive quantities of foam directly onto soil and into waterways.
Civilian airports: Commercial airports with firefighting capabilities used AFFF for training and emergency response. Major hub airports may have contaminated groundwater supplies serving nearby communities.
Fire training facilities: Local fire departments and fire academies used AFFF in burn pits and training exercises. Many of these facilities were located near residential areas.
Industrial fire suppression: Oil refineries, chemical plants, and other industrial facilities with fire suppression systems used AFFF-based sprinkler and suppression systems.
The Department of Defense has begun transitioning to fluorine-free firefighting foams, but the transition is slow and incomplete. Meanwhile, the PFAS already released into the environment will persist for centuries.
A small number of companies manufactured the vast majority of PFAS used worldwide:
3M (Minnesota Mining and Manufacturing) - Produced PFOS, PFOA, and related compounds from the 1950s to 2002 - Primary manufacturer of Scotchgard and AFFF - Internal documents show 3M knew about PFAS toxicity as early as the 1970s - Agreed to $10.3 billion settlement for water contamination
DuPont / Chemours - Used PFOA in Teflon manufacturing from the 1950s onward - Washington Works plant in Parkersburg, WV is one of the most contaminated sites in the country - Spun off PFAS liabilities to Chemours in 2015 - Combined $1.19 billion settlement
Chemours (DuPont spinoff) - Manufactures GenX as a PFOA "replacement" - Fayetteville Works plant in North Carolina has contaminated the Cape Fear River - Air emissions have contaminated rainwater and wells miles from the facility
Solvay - Produces specialty PFAS for industrial applications - Facilities in New Jersey and West Virginia linked to contamination
Manufacturing facilities contaminate water through multiple pathways:
Products containing PFAS – carpets, clothing, food packaging, electronics – eventually end up in landfills. As these products decompose, PFAS leaches into the liquid that percolates through the waste (called "leachate"). This leachate carries PFAS into groundwater if the landfill liner is inadequate or damaged.
Studies have found PFAS in leachate from virtually every landfill tested. Older landfills – built before modern liner requirements – pose the greatest risk because they lack barriers between waste and groundwater.
Wastewater treatment plants receive PFAS from household drains, industrial discharge, and stormwater. The treatment process doesn't destroy PFAS – it concentrates it in the solid waste (biosolids or sewage sludge) that remains after treatment.
For decades, these biosolids have been spread on farmland as fertilizer. The PFAS in the biosolids then contaminates:
This pathway was discovered relatively recently and is now considered one of the most significant routes of PFAS exposure through food.
PFAS is used in an astonishing variety of consumer products. Here are the major categories:
Kitchen: - Non-stick cookware (Teflon, ceramic coatings marketed as "green") - Microwave popcorn bags - Fast food wrappers and containers - Pizza boxes - Some baking papers
Clothing and Textiles: - Waterproof jackets (Gore-Tex, similar technologies) - Stain-resistant fabrics (Scotchgard-treated) - Outdoor gear (tents, sleeping bags, backpacks) - Some school uniforms and workwear - Carpets and rugs
Personal Care: - Foundation and concealer (especially "long-wear" formulas) - Mascara - Lipstick and lip gloss - Sunscreen - Dental floss (some brands use PTFE/Teflon) - Shaving cream
Household: - Stain-resistant upholstery - Carpet treatments (Stainmaster) - Some cleaning products - Non-stick bakeware - Waterproof sprays for shoes and clothing
Individual consumer products release small amounts of PFAS, but the cumulative effect is enormous. PFAS from consumer products enters the waste stream through:
Beyond military airports, civilian transportation infrastructure contributes to PFAS contamination:
PFAS are entirely synthetic – they do not occur naturally. Any PFAS found in the environment was put there by human activity. This is an important distinction because it means every case of PFAS contamination has a responsible party.
The biggest predictor of your personal PFAS exposure is your proximity to contamination sources. If you live within 5 miles of:
...your water supply may be at elevated risk for PFAS contamination.
The best way to check: Enter your ZIP code into our free lookup tool. We've aggregated all available EPA testing data so you can see whether PFAS has been detected in your water system.
Firefighting foam (AFFF) used at military bases and airports is the single largest source of drinking water PFAS contamination. Industrial manufacturing discharge is the second largest source. Together, these two sources account for the majority of known contaminated water systems.
Yes. While some of the most toxic PFAS compounds (PFOA, PFOS) have been largely phased out of production in the United States, thousands of PFAS compounds are still manufactured and used. "Replacement" PFAS – marketed as safer alternatives – are now being found in water supplies and raising new health concerns.
Often, yes. Environmental forensic analysis can identify contamination sources through chemical fingerprinting (which specific PFAS compounds are present), groundwater flow modeling, and historical records of PFAS use at nearby facilities. This tracing is a critical component of PFAS lawsuits.
Standard water treatment processes (chlorination, flocculation, sedimentation) do NOT remove PFAS. Specialized treatment – granular activated carbon, ion exchange, or reverse osmosis – is required. Many utilities are now upgrading their systems, but the compliance deadline is 2029.
PFAS can travel significant distances in groundwater – contamination plumes extending 5-10+ miles from source sites have been documented. In surface water (rivers, streams), PFAS can travel hundreds of miles. Air emissions from industrial facilities can deposit PFAS across an even wider area through rainfall.
You can Check your water quality by zip code to see if your area is affected. If you're looking for solutions, Find water filters that remove PFAS certified for removal. For more details on what's in your tap water, Get a detailed water quality report for your area.
Check your water now. Enter your zip code at KnowYourExposure.com to see what contaminants have been detected in your local water supply – including PFAS, lead, and other regulated compounds.