PFAS Information

Our District continues to receive high quality drinking water supplies from two protected watersheds in the Cascade range, the Tolt and Cedar River reservoirs.  No PFAS detections have been found in these reservoirs since detection efforts began in 2015!

To meet Department of Health requirements the District will test 29 PFAS compounds and lithium starting in the fall of 2024, the sampling is each quarter for one year.  In 2015 the District performed UCMR3 sampling which included 6 PFAS contaminants resulting in no detection.

PFAS Information – Seattle Public Utilities

https://www.seattle.gov/utilities/your-services/water/water-quality/quality-concerns/pfas

Seattle's drinking water remains safe and protected from contaminants, including the group of man-made chemicals labeled PFAS (per- and polyfluoroalkyl substances).

PFAS are manufactured for a variety of industrial purposes. If detected in drinking water, PFAS have the potential to raise health concerns.

For more information about PFAS, including the health and safety risks associated with these compounds, visit the Environmental Protection Agency and Washington State Department of Health websites.

In 2023, SPU conducted four rounds of PFAS testing for the Cedar and Tolt supplies in compliance with state and federal regulations. Although PFAS had not been previously regulated and routine testing had not been required prior to 2023, Seattle Public Utilities (SPU) also conducted testing in 2015, 2018, and 2022.

Tolt and Cedar River Test Results

  • In 2015, SPU tested its Tolt and Cedar River surface water sources for six types of PFAS. Test results in 2015 showed no detection of PFAS.
  • In October 2018, SPU conducted additional tests on the Tolt and Cedar water supplies, this time using a more sensitive sampling method and testing for 14 types of PFAS. Test results again showed no detection of PFAS and Seattle's surface water supplies continue to be safe and protected from contaminants. A summary of the 2018 tests is shown in the table below.
  • In compliance with recently established state and federal regulations for PFAS, in March of 2023, SPU began testing its Tolt and Cedar River surface water sources again. Those results are posted on this web page.

Seattle Wells Test Results

  • In addition to the City's primary surface water sources (Tolt and Cedar River supplies), Seattle also has wells available for emergencies. The wells are not used very often, and they have not been used since 2015.
  • As a precaution, SPU tested the wells for PFAS in October 2018. Two of the three wells had no detection of PFAS. Trace detections of several PFAS compounds were measured in the third well with a maximum concentration of 5 parts per trillion (see 2018 table). 
  • The wells were tested again in August 2022. Two of the three wells had no detection of PFAS. Trace detections of several PFAS compounds were measured in the third well (Blvd Park) with a maximum concentration of 5 parts per trillion (see 2022 table). In all cases with the exception of the PFOA compound, the amount detected was far below health advisory levels established by the Washington State Department of Health (DOH) and the U.S. Environmental Protection Agency (EPA). ). In the case of the PFOA compound, the DOH advisory level is 10 parts per trillion and the EPA proposed MCL is 4 parts per trillion. The PFOA level in the Blvd Park well was 5.7 parts per trillion. The tests conducted in 2018 and 2022 on the wells were done without putting any well water into the drinking water system.

Results Summary 2023

Samples collected from the Cedar and Tolt treatment facilities finished waters in 2023 have not shown any detections for the 29 PFAS compounds in the analyses.  Samples were collected in June, July, October, and December 2023 as part of UCMR5 required monitoring.

Washington State Department of Health PFAS FAQ’S

 https://doh.wa.gov/community-and-environment/contaminants/pfas

Are there federal drinking water standards for PFAS?

Yes, on April 10, 2024, EPA announced a final federal rule that regulates six PFAS in drinking water. Learn more at EPA's Per- and Polyfluoroalkyl Substances (PFAS) webpage.

What are Washington State's PFAS drinking water standards?

In 2021, the Washington State Board of Health adopted State Action Levels (SALs) for five PFAS.

  • A SAL is a level that is set to protect human health and is based on the best available science at the time.
  • The state rule requires all community and nontransient-noncommunity public water systems to test for PFAS. Transient public water systems may also be required to test for PFAS if contamination is discovered nearby. Under the state rules, over 2,400 Washington water systems will test for PFAS in the next 3 years.
  • If water systems find PFAS in their water, they must notify their customers and do follow-up testing. Community water systems that find any level of PFAS must include the test results in their annual water quality report.
  • All drinking water testing data on PFAS will be reported to DOH and made publicly available.
  • In addition to these required actions, SALs provide advice for when to take action to lower PFAS in drinking water for long-term consumption (over years). This advice should also be followed over shorter periods of time (months) for sensitive groups, such as infants and people who are pregnant or breastfeeding.
  • We do not have enough information to recommend SALs for every type of PFAS that may be in drinking water. However, technologies that remove PFAS with SALs will remove many other PFAS from water.
  • One of the challenges of providing health guidance for PFAS is that these chemicals are still being researched. Health advice is updated as new science becomes available.

Type of PFAS

2021 WA SALs

PFOA

10 ppt*

PFOS

15 ppt*

PFNA

9 ppt*

PFHxS

65 ppt*

PFBS

345 ppt*

*ppt = parts per trillion or ng/L.

What are EPA's health advisory levels for PFAS in drinking water?

EPA developed Health Advisory Levels (HALs) for several PFAS to provide guidance until enforceable safety standards are adopted under the Safe Drinking Water Act. The HALs are health goals that help guide safety decisions when a contaminant occurs in drinking water. HALs represent an amount of each PFAS in drinking water that is almost certain not to cause harmful human health effects if consumed over a lifetime. HALs are not regulations and are not enforceable. They are based on the best available science at the time and can change as the science is updated.

In 2016, EPA established a lifetime health advisory level (HAL) of 70 parts per trillion for PFOA and PFOS combined in drinking water. The military has followed this federal health advisory at and near military bases in Washington State.

In June 2022, EPA released new HALs for four PFAS in drinking water.

Type of PFAS

2016 EPA HALs

2022 EPA HALs

PFOA

70 ppt*

0.004 ppt*

PFOS

70 ppt*

0.02 ppt*

PFBS

--

2,000 ppt*

GenX

--

10 ppt*

*ppt = parts per trillion or ng/L.

  • The updated HALs for PFOA and PFOS are temporary values because they are being reviewed by experts. EPA now considers any detectable levels of PFOA and PFOS in drinking water a potential concern over a lifetime of exposure.
  • We aren't currently aware of any GenX chemicals in Washington state water systems.

 How do I know if my drinking water contains PFAS?

If you get your water from a public water system, ask your water system if they have tested for PFAS. Many water systems in Washington have voluntarily tested for PFAS and many more will test under the 2021 Washington State Board of Health rule requiring public water systems to test for PFAS and share the results.

If you have a private well, you can test your water for PFAS. This can cost you about $300-$600. Ask your local government if PFAS have been discovered near your well. Being close to a contaminated site doesn’t necessarily mean there are PFAS in your drinking water, but it may help you decide whether or not to test.

Water testing is the only way to know for sure if PFAS are present. You can’t see, taste, or smell PFAS in your water.

New grant funding is available to help pay for water testing and alternative sources of drinking water when individual wells and Group B water systems are impacted by drinking water contaminants. Read the flyer for more information. Also available in:

How do I test my water for PFAS?

Testing your water involves collecting a water sample and sending it to a laboratory that can measure PFAS in drinking water.

If you choose to test your water, find a lab that has been accredited (verified) by the Washington State Department of Ecology as able to test for PFAS in drinking water. There are two test methods. EPA method 533 tests for 24 PFAS. EPA method 531.7 tests for 18 PFAS. Both will detect the five PFAS with a SAL.

Learn more about EPA's PFAS Drinking Water Laboratory Methods.

What water filters work for PFAS?

There are two types of home filter systems: point-of-use (POU) and whole house filters. 

What Our State is Doing to Address PFAS Contamination

State Standards for PFAS in Drinking Water

The State Board of Health adopted standards for PFAS in Group A public drinking water systems in October 2021. To support this process, the Department of Health reviewed the most current science and recommended state action levels on five PFAS compounds to protect public health. The new rule also requires monitoring, recordkeeping and reporting, follow-up actions, and other associated requirements for PFAS. For more information go to our PFAS in Drinking Water 2021 Rulemaking Documents webpage.

Statewide Action Plan for PFAS

The Departments of Ecology and Health developed a statewide Chemical Action Plan (CAP) for PFAS to address human exposure and environmental contamination. The plan was developed with broad stakeholder input. It summarizes what we know about PFAS contamination in Washington State and recommends actions to address contamination and human exposure. Recommendations include expanded testing and mitigation for PFAS in drinking water, reduction of PFAS uses that release PFAS into food, drinking water, or the environment, and additional evaluation of PFAS in waste streams (landfill leachate, biosolids, sewage treatment outfalls, etc.) Visit the Department of Ecology's website to learn more about this work.

State Ban on PFAS in Firefighting Foam

In 2018, the Washington State legislature restricted the use of PFAS in firefighting foam and banned fire training with PFAS firefighting foams. The law also requires reporting of PFAS in firefighter’s personal protective equipment. (RCW 70A.400) Firefighting foam is a suspected source of some drinking water contamination found near airports, military bases, and fire training areas. The state is helping fire departments and other businesses safely dispose of existing stockpiles of PFAS foams. Visit the Department of Ecology's website to learn more about this work.

State Ban on PFAS in Food Contact Papers

In 2018, the Washington State Legislature restricted use of PFAS in food contact papers and paperboard, once safer alternatives are identified (RCW 70A.222). The Department of Ecology has so far identified safer alternatives for nine types of food contact packaging and continues to look for safer alternatives for other types. PFAS will be restricted in food wrappers and liners, plates, food boats, and pizza boxes starting in February 2023. In 2024, PFAS will be restricted in paper bowls, bags and sleeves, trays, open top containers like cups, and containers that close like clamshells. Visit the Department of Ecology's website to learn more.

State Ban on PFAS in Cosmetics

In 2023, the Washington State Legislature restricted intentionally added PFAS and eight other potentially harmful types of chemicals in cosmetics and personal care products sold in Washington state. RCW 70A.560. The ban goes into effect in January 2025. 

Safer Products for Washington

In 2019, the Washington State legislature authorized the Department of Ecology, in consultation with Department of Health, to further restrict PFAS and other harmful chemical classes in consumer products. This law outlined a five-year process to identify problem products, safer alternatives, and regulatory solutions. The state restricted PFAS in carpets and indoor furnishings and in after-market sprays for waterproofing and stain-proofing fabrics in 2023. Currently the state is considering taking action on PFAS in apparel, outdoor gear, firefighting gear, cleaning products, waxes and polishes, surface sealants, cookware, and kitchen supplies. Learn more at Safer Products for Washington.