PFAS in drinking water

Per– and polyfluoroalkyl substances, or PFAS, are a large group of human-made chemicals used for decades in many products, such as firefighting foam, water-resistant clothing, stain-resistant carpets, non-stick cookware, food packaging, and cleaning products. PFAS are used in products for their strength and resistance to heat, water, and oil. These manufactured chemicals do not break down or disappear naturally in the environment, which is why they are called “forever chemicals.” They can cycle through the air, soil, and water and enter the food chain.

People can be exposed to PFAS in drinking water, food, indoor dust, some consumer products, and workplaces. One of the main sources for potential exposure is drinking water that has been contaminated by PFAS.

When PFAS are made, used, disposed of, or spilled near water sources, like rivers, aquifers or wells, the chemicals can get into drinking water. Because PFAS do not break down easily, they may remain in water supplies for many years and have been found in people, wildlife, and fish.

PFAS are a public health concern because they:

  • Can impact human health.
  • Can build up in animals, fish, birds, plants, and people.
  • Don’t break down in water, soil, or air.
  • Can travel large distances in water or air.

Not all PFAS have the same impact on people or the environment. Watch the video “What are PFAS?” from the Minnesota Pollution Control Agency to learn more.

How to check your water source for PFAS

The presence of PFAS in drinking water can only be determined through laboratory testing.  You can’t see, taste, or smell PFAS in your water. Steps for testing drinking water will depend on if the property’s water source is a private or public water system.

Private water systems and individual wells

People who are concerned the water from their private wells may contaminated can conduct testing for PFAS. The cost of testing is about $300-$600. A water sample can be sent to one of the PFAS drinking water accredited labs.

Because PFAS can be in many household items, it is easy to contaminate a water sample. Before deciding to test water from a private well, discuss proper sampling steps with the selected accredited lab to ensure results are accurate.

Public water system

Contact the public water system provider to ask if they have tested for PFAS and whether any actions have been taken to reduce the level of PFAS. Water systems are required to test for PFAS and share results under the 2021 Washington State Board of Health rule.

Unsure how to check your public water source? Check out instructions on how to look up a property’s water district.

Frequently asked questions


Scientists are still studying how PFAS affect people’s health. Some PFAS can build up in people’s bodies and, over time, may cause harmful health effects. Higher exposure to certain PFAS may lead to:

  • Increased cholesterol levels
  • Changes in liver enzymes that indicate liver damage
  • Decreased immune response to vaccines in children
  • Increased risk of high blood pressure or pre-eclampsia during pregnancy
  • Decreased birth weights
  • Increased risk of thyroid disease
  • Increased risk of kidney or testicular cancer

Children ages 0-5 years, and people who are pregnant, planning to become pregnant, or breastfeeding are more vulnerable to health impacts from these chemicals.

Scientists are still learning about the health effects of exposures to mixtures of PFAS.

If you have questions or concerns about your health, contact your health care provider. 


People can be exposed to PFAS in drinking water, food, indoor dust, some consumer products, and workplaces. Most exposures that do not happen at work occur by drinking contaminated water or eating food that contains PFAS.

Although some types of PFAS are no longer used, some products may still contain PFAS:

  • Food packaging materials
  • Nonstick cookware
  • Stain resistant carpet treatments
  • Water resistant clothing
  • Cleaning products
  • Paints, varnishes and sealants
  • Firefighting foam
  • Some cosmetics

Limit drinking water or eating food that contains PFAS. At-home water treatment systems filter contaminants out of water and can help reduce your exposure to PFAS in household tap water used for drinking and cooking.

  • Reduce use of products that contain PFAS. Find PFAS-free consumer products.
  • Follow any drinking water advisories issued by your water system or local government.
  • Follow local fish advisories.

Watch for more on reducing your exposure to PFAS.


You cannot boil water to remove PFAS. However, showering, bathing, doing laundry and washing dishes are okay because they are not meaningful sources of PFAS exposure.


Some water filters that attach to the faucet or go under the sink can help reduce your exposure to PFAS in household tap water used for drinking and cooking. But not all filters reduce PFAS.

To learn more about water treatment options and finding filter products that remove PFAS: Home water treatment for PFAS (Spanish)

Use of water filters requires ongoing maintenance and testing to ensure they are effectively removing PFAS. When selecting a filter product, follow the manufacturer’s instructions for filter replacement and care. 


Public Health does not recommend people make their own water filters for PFAS. Water filters for drinking water treatment should meet the NSF/ANSI 61: Drinking Water System Components – Health Effects standard. The standard certifies that the chemicals and materials used to treat drinking water are safe and will not produce negative health effects. Choosing uncertified materials could add unknown contaminants to the drinking water during the water filtration process.  

To learn more about water treatment options and finding filter products that remove PFAS: Home water treatment for PFAS (Spanish) (Russian) (Tagalog) (Ukrainian) (Vietnamese)


People who receive water from a public water system can contact the system to determine if they’ve detected PFAS, and if so, what steps they are taking to treat or remove PFAS.

Public Health continues to work with local public water systems, the Washington Department of Health and Department of Ecology to determine if there are significant sources of PFAS contamination in Clark County drinking water sources. If major sources of PFAS are discovered, Public Health will work with these agencies to determine the appropriate next steps and provide information to the public.

For more answers to common questions, visit Washington State Department of Health’s PFAS frequently asked questions.

Clark County residents can contact Public Health with questions, concerns or comments about PFAS in drinking water by calling 564.397.8000 or by clicking the button below.