Information on PFAS

What are PFAS?

 Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals used since the 1940s in common household and commercial products. PFAS have unique chemical properties and are often used to keep food from sticking to cookware. They also make clothes, carpets, and furniture resistant to water and stains.

Many recent news articles and movies focus on PFAS, typically when they are found in local drinking water. Because we test for PFAS in water, however, you may hear more about PFAS in water than from other sourcesWater gets this media attention because it is regularly tested for potentially harmful chemicals by law, unlike many of the other things we eat, drink, and breathe. Understanding how PFAS can enter our environment, our homes, and our bodies can help us manage our exposure.

How Does PFAS Enter the Environment?

 PFAS are slow to break down in the environment and can move far from their original use areas. The manufacturing and use of products with PFAS puts PFAS into the environment, where, over time, they may end up in drinking water supplies.

  • PFAS can enter the environment as we throw away products that have PFAS, and through our own bodily waste.
  • PFAS can also enter the environment when companies make products with PFAS, releasing them directly into our water and air.
  • Natural breakdown of PFAS is negligible or sometimes non-existent, allowing PFAS to build up and remain in the environment. This leads to increasing levels of PFAS in the natural resources we use from the environment, like water, food, and soil.


How are Humans Exposed

Because PFAS are used in so many everyday products, most people in the United States and other industrialized countries now have PFAS in their blood. Exposure to PFAS depends on many things, including the amount of PFAS in your local environment, the amount of PFAS in food, water, or other products, and how much a person eats, drinks, or uses those products.

  • We swallow, inhale, or rub PFAS into our skin by using certain products, eating or drinking impacted food and water, and breathing in the dust in our homes.
  • As in the environment, PFAS can build up in the human body over time and have been associated with some negative health effects.


What is Purcellville Doing to Manage PFAS?

In March 2023, the U.S. Environmental Protection Agency (U.S. EPA) announced proposed Maximum Contaminant Levels (MCLs) for six PFAS compounds. An MCL is the legal limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act. The proposal includes:

  • PFOA and PFOS: EPA is proposing an MCL of 4 parts per trillion (ppt).
  • PFNA, PFHxS, PFBS, and GenX Chemicals: EPA is proposing a regulation to limit any mixture containing one or more of these compounds. For these PFAS, water systems would use an established approach called a hazard index calculation to determine if the combined levels of these PFAS pose a potential risk.  The proposed hazard index is 1.0 (unitless). 

The Town is voluntarily participating in the Virginia Department of Health (VDH) Occurrence Study for PFAS that began in July 2022 and extends through Spring 2023. As part of that study, VDH collected samples from the Town’s Surface Water Treatment Plant located north of Town. VDH will post the results of that study on their website when complete: Per- and Polyfluoroalkyl Substances (PFAS) in Drinking Water - Drinking Water (

The VDH Occurrence Study included samples from the Town’s surface water source only. The Town recently initiated voluntary sampling for PFAS at all of the Town’s water sources. One round of sampling is complete, and the results are presented below.

SUMMARY OF PFAS DATA (Analyzed March 2023)
Water SourceHazard Index
Surface Water<1non-detectnon-detect
Wells<1non-detect to 10non-detect to 4.7

The Town’s voluntary PFAS testing will continue through 2023, and we are following the guidance of EPA and the Virginia Department of Health. Final standards for PFAS are anticipated in December 2023. Until the standards are finalized, the Town is managing water operations to minimize PFAS compounds in water supplies to be under the proposed EPA standards.

For more information on PFAS:

  1. Please call us at 540-338-2513
  2. Review the attached informational brochure from the Water Research Foundation 
  3. Visit VDH’s website at Per- and Polyfluoroalkyl Substances (PFAS) in Drinking Water - Drinking Water (
  4. Visit EPA’s website at  Per- and Polyfluoroalkyl Substances (PFAS) | US EPA


*PFAS Acronyms:

PFOA: Perfluorooctanoic Acid

PFOS: Perfluorooctane sulfonic acid

GenX : 2,3,3,3-Tetrafluoro-1-(1,1,2,2,3,3,3-heptafluoropropoxy)-propanoic acid

PFNA: Perfluorononanoic Acid

PFHxS: Perfluorohexane sulfonic acid

PFBS:  Perfluorobutane sulfonic acid