Drinking Water PFAS Testing Results Data

The Washington State Department of Health (DOH) collects drinking water test results for a large family of chemicals called per- and polyfluoroalkyl substances (PFAS). PFAS chemicals are sometimes called "forever chemicals" in the news because they stay in the environment for a very long time. PFAS chemicals are a health concern because some can build up in our bodies when we’re exposed for a long time, such as months to years. This is a problem, because studies show that having higher levels of PFAS chemicals in our bodies could increase our risk for negative health impacts.

The Washington State Board of Health adopted a rule in 2021 that required over 2,400 public drinking water systems, also known as “Group A” systems, to test for PFAS. Learn more about public drinking water systems, EPA. Testing must be completed by December 2025. Water systems that find PFAS above a state action level (SAL) must notify their customers within 30 days, and test more often. Learn more about State Action Levels for PFAS (PDF). Our state is phasing in new federal standards for 6 PFAS and will update this dashboard before those standards become enforceable.

Why PFAS Testing Data is Important

Washington's state action levels require water systems to test for PFAS, inform communities about PFAS in their drinking water, and relay what is being done to address the PFAS. This is important, because it allows communities to be aware of exposure, and actions being taken to get PFAS to safe levels again. When you lower your exposure, PFAS chemicals can start slowly leaving your body.

Testing results show you where PFAS have and haven’t been found in public drinking water sources. They also show if the levels are higher than our state action levels. Contact your water system to learn more about their response to PFAS. Some water systems have already taken steps to lower PFAS in their water.

If you are a Group B water system or a private well owner, you are not currently required by the state to test for PFAS. You can use the map to learn if PFAS have been detected nearby. This can help you decide whether to test your well for PFAS.

Over 2400 drinking water systems will test for PFAS under state rules

Only 2% of tested water systems have found PFAS over a state action level

Historical use of firefighting foam is a common source of PFAS in our drinking water

View the Data

PFAS Data

What’s Here

The dashboard shows data from PFAS water testing that is required under the 2021 state rule. Public water systems must test all active, permanent, and seasonal sources of their water supply. An example of a source is a river or a lake. A source could also be groundwater well that taps into water that flows or pools underground.

Water is tested after all water treatments (like disinfection) are completed and before the water is distributed to water customers. The dashboard includes results from each source tested within a water system.

A PFAS detection at a single water source doesn’t necessarily mean these levels are present everywhere in the water system or at nearby homes. If you are concerned about PFAS levels at your home, please call your water system. Your water system’s contact information is on your water bill, or you can look it up on the internet.

Water systems must use EPA test method 537.1 (18 PFAS analytes) or EPA test method 533 (24 PFAS analytes). Results for all PFAS chemicals from the tests are included in this dashboard.

Test results are shown in a map and in the table. Click on each dot in the map to see more information about the water system and source. Use the filter options on the left side of the table to see detailed PFAS results from specific water systems or sources. The dashboard also has a summary tab with PFAS testing statistics for commonly asked questions.

The map can be used to:

View the most recent test results for each water system and source.
- This view helps you understand current conditions in water systems, including any changes in PFAS water concentration after action was taken to reduce levels of PFAS.
View the highest historical test result reported for each source.
- This view shows where PFAS may still impact a drinking water supply (such as a groundwater aquifer).
- If you are near an area with a high PFAS detection, you might choose to test your water source even if you aren't required to test.

In the future, we will also include water testing data from military testing and other local PFAS testing in drinking water.

How to Reduce Exposure to PFAS in Drinking Water

If your water has PFAS above a state action level, you can reduce your exposure to PFAS by installing a water filter that reduces PFAS in the water you use for cooking, drinking, and preparing infant formula. Filters come in different styles and can treat water at your kitchen sink, refrigerator, or in a countertop water pitcher. You can also use bottled water labeled as “purified” as a short-term alternative.

Taking action to lower your exposure is especially important for pregnant and breastfeeding people, infants, and children younger than 6. These groups may be especially sensitive to harmful effects of PFAS because they drink more water per pound of body weight than most people, which increases their exposure.

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For information or questions, email the Washington Tracking Network.

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