PFAS in the Environment

Where PFAS are found

EPA states that “PFAS are found in water, air, fish, and soil at locations across the nation and the globe.” ^[1] Because “many break down very slowly,” they “can build up in people, animals, and the environment over time.” ^[2]

The U.S. Geological Survey (USGS) describes how PFAS from sources such as firefighting foams “persist in groundwater and move into nearby surface waters, creating long-term exposure pathways for humans and other aquatic species, including fish.” ^[3]

Main sources of contamination

EPA lists these among the main sources of PFAS in the environment: ^[2]

• Firefighting foam used in training and emergencies at airports, shipyards, military bases, firefighting training facilities, chemical plants and refineries.
• Manufacturing and chemical production facilities that make or use PFAS, such as chrome plating, electronics and some textile and paper plants.
• Waste sites, including landfills, disposal sites and hazardous waste sites.
• Biosolids: fertilizer made from wastewater treatment plant residue that is spread on farmland “can affect ground and surface water and animals that graze on the land.”

PFAS in U.S. tap water

A USGS study published in July 2023 estimated that “at least 45% of the nation’s tap water” has one or more types of PFAS. ^[4] Keep the study’s limits in mind:

• It tested for 32 PFAS, out of more than 12,000 known types, “not all of which can be detected with current tests.” ^[4]
• It was based on samples taken between 2016 and 2021 from private wells and public supplies at 716 locations. ^[4]
• USGS estimated the chance of finding no PFAS in tap water at about 75% in rural areas and about 25% in urban areas. ^[4]

Drinking water limits

On 10 April 2024 EPA announced the first enforceable national drinking water standards for PFAS, covering six compounds: ^[5]

Public water systems have until 2027 to complete initial monitoring and “five years (by 2029)” to reduce PFAS if levels exceed the limits. ^[5]

Superfund designation

On 19 April 2024 EPA designated PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, also known as Superfund); the rule took effect on 8 July 2024. ^[8] The designation “enables cost recovery and enforcement authorities” so that “the polluters pay for investigations and cleanup.” ^[9] On 17 September 2025 EPA said it is “currently retaining the rule.” ^[10]

Fish and food

PFAS can build up in fish. A USGS field study found that PFAS uptake in fish generally increased with longer carbon chains. ^[11] In July 2024 EPA added twelve PFAS to the contaminants it recommends states and Tribes monitor in locally caught fish, noting that “many states are already monitoring for certain PFAS in fish and using local data to issue fish consumption advisories.” ^[12]

FDA testing detected one or more PFAS in 69% of seafood samples in its Total Diet Study and in 74% of samples in its 2022 targeted seafood survey. ^[13]

Removing PFAS from water

EPA identifies three technologies that remove PFAS from drinking water: “activated carbon adsorption, ion exchange resins, and high-pressure membranes.” Reverse osmosis and nanofiltration membranes are “typically more than 90 percent effective at removing a wide range of PFAS, including shorter chain PFAS.” ^[14]

For home filters, EPA advises looking for “certification under NSF/ANSI 53 or NSF/ANSI 58 for PFAS reduction” and replacing filters as the manufacturer instructs. EPA also cautions that current certification standards “do not yet indicate that a filter will remove PFAS down to the levels EPA has now set.” ^[15]

Disposal and destruction

EPA publishes non-binding interim guidance on destroying and disposing of PFAS and PFAS-containing materials, now in its 2026 edition. It covers three large-scale options: “thermal destruction, landfills, and underground injection.” ^[16]