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 be 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.

Private water system and well owners considering testing can use the state Department of Health's PFAS testing results dashboard to see if PFAS have been detected nearby.

For more information, see the common questions about PFAS and private wells (Spanish)

Public water system

Contact the agency that sends your water bill 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 who provides your water? If you do not receive a water bill, check with your landlord, property management or whoever you rent through.

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.

If there are PFAS above recommended limits in your drinking water, you can reduce your exposure by installing a water filter that reduces PFAS or by using an alternate source of water for cooking, drinking, and preparing infant formula. This is especially important for people who are pregnant or breastfeeding and formula-fed infants, as these groups are in life stages when they may be especially sensitive to harmful health effects of PFAS


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:

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:


Bottled water can be a good short-term solution until a filter or other solution is in place. For long-term use, bottled water is not as regulated as tap water for many other contaminants and usually ends up costing more than installing and maintaining a filter. Compared to tap water, bottled water also has higher environmental impacts linked to trucking the bottled water to market and making and disposing the plastic bottles.

PFAS have been found in some brands of bottled water. If you use bottled water as an alternate water source, look for brands that have been purified with water filtration.

To learn more about bottled water as an alternative:


If PFAS are above health advisory levels in your drinking water, Washington State Department of Health recommends installing a filter or switching to an alternative source of drinking water and continue to breastfeed your baby. In Washington state, state action levels were set specifically to protect breastfed infants.

The American Academy of Pediatrics states that: “even though some environmental contaminants like PFAS pollutants pass to the infant through breast milk, the advantages of breastfeeding greatly outweigh the potential risks in nearly every circumstance.”

Talk to your health care provider if you have concerns about PFAS and breastfeeding.


If PFAS are above recommended limits in your tap water, Washington State Department of Health recommends installing a filter or switching to an alternative source of water to mix infant formula.


If you have questions or concerns about exposures to PFAS and your health, contact your health care provider.

If you choose to have your blood tested, test results will tell you how much of each PFAS is in your blood, but it is unclear what the results mean in terms of possible health effects.

Test results cannot measure your PFAS exposure from a specific source, such as drinking water. Instead, the test measures total exposure to these chemicals from all sources.

The blood test will not provide information to pinpoint a health problem, and it will not provide information for treatment. The blood test results will also not predict or rule out the development of future health problems related to a PFAS exposure.


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.