PFAS Information


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​​​​ 919 Sunset Road, Ann Arbor, MI 48103

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(excluding holidays)

24/7 water emergency line



Molly Maciejewski,
Water Treatment Services Manager


​​​​​​​​​​​​​​​​​Quick Lin​​ks

What is P​FA​S?

It is an abbreviation for per- and polyfluoroalkyl substances which are man-made chemicals used in metal plating and a wide variety of consumer products including fire-suppressing foam, carpets, paints, polishes and waxes. The most studied types of PFAS are perfluorooctanoic acid (PFOA) and perfluoroctanesulfonic acid (PFOS).​

What are the maximum ​contaminant levels for PFAS?

Michigan Department of Environment, Great Lakes, and Energy (EGLE) established maximum contaminant levels for seven PFAS compounds in August of 2020, including PFOS (16 ng/L), PFOA (8 ng/L), PFNA (6 ng/L), PFHxS (51 ng/L), HFPO-DA also known as GenX (370 ng/L), PFBS (420 ng/L), and PFHxA (400,000 ng/L). On March 14, 2023 the U.S. Environmental Protection Agency (EPA) proposed drinking water regulations for PFAS, and final regulations are expected by the end of 2023 or early 2024. Ann Arbor already meets EPA’s proposed PFAS regulations as well as EGLE's regulations and produces water that is protective of public health. In addition to meeting EGLE and EPA regulations, Ann Arbor holds itself to a higher standard and works to maintain less than 8 ng/L of PFOS plus PFOA combined and less than 50 ng/L for the sum of all PFAS. ​

What are the advisory levels for PFAS?

In s​ummer of 2022, EPA proposed health advisory levels for four PFAS compounds, including PFOS (0.020 ng/L), PFOA (0.004 ng/L), GenX (10 ng/L), and PFBS (2,000 ng/L). While regulations such as maximum contaminant levels (MCLs) can be enforced, health advisories cannot and are often established before regulation is developed by EPA. Health advisories represent the lowest concentration that may cause health risks to an individual in a sensitive population with a lifetime of exposure. They also take into account other potential sources of exposure beyond drinking water (for example food and consumer products), which provides an additional layer of protection.

What is being done to protect our drinking water from P​​​FAS?

Several of the new health advisory levels are below the limit that any known method can quantify today, specifically for PFOS and PFOA. We are aware that these health advisory levels are lower than the regulated values from the state of Michigan and the levels that the best detection methods can achieve.  We are still confident that our water is safe. That is because City of Ann Arbor has installed granular activated carbon (GAC) treatment for PFAS, one of the best technologies that exist today for removal of PFAS. We are confident in this this technology because it has proven reliable for PFAS removal for many years in countless applications across the globe and is considered one of the best available technologies recommended for water utilities. Furthermore, we installed our own pilot filters, tested several GAC medias ourselves, and selected the GAC filter media that was most effective at removing PFAS.

We continue to meet all PFAS regulations in our finished drinking water, we already meet EPA's proposed PFAS regulations, and are watching closely for regulatory developments as Maximum Contaminant Levels (MCLs) for several PFAS are expected to be finalized by EPA in the coming year. We are also monitoring our PFAS concentrations regularly with the best methods that exist, achieving the lowest possible detection limits, and posting that data for our customers on our website. We are watching for any new discoveries in the analytical technology for PFAS and will evaluate newer methods if they are developed and proven to be reliable.  

Part of our approach to addressing emerging contaminants such as PFAS is to participate in research to ensure we are using the best available technology and tools to remove contaminants from our source waters.  Our research has not only led us to select one of the best available technologies for PFAS removal for municipal water systems, but has also enabled us to optimize replacement of our filter media.  The GAC in our filters is regenerated every 3 years at an average cost of $250,000 per year to ensure maximum PFAS removal. We will continue to participate in PFAS research projects to ensure you, our customers, have access to the best and most current solutions and technology.  

What are the levels of PF​​AS in Ann Arbor’s drinking water?

Ann Arbor a​lready meets EPA’s proposed PFAS regulations as well as EGLE's regulations and produces water that is protective of public health. 

City of Ann Arbor monitors its source water and finished water regularly for 28 PFAS compounds, including all regulated compounds, the six compounds included in EPA's proposed drinking water regulations, and the four the compounds included in the EPA health advisory. We post our data at the link on the top of this website as it becomes available. Analysis times are often greater than a month, but you will find the most recent data we have on our website. 

Where can I view PFAS test results?

Each month, the c​​ity publishes to the top of this webpage​ the independent lab verified testing results of PFAS in the source water and finished drinking water.  

Why doesn’t the city test for PFAS at my home?

PFAS concentrations do not change from the wat​er treatment plant to your home, therefore, there is no need to test for PFAS within homes.

What a​​re you doing to protect our waterways?

While we have been able to effectively treat our source waters to ensure the safety of the city's drinking water, the most effective tool to protect the city's water supply is to eliminate these harmful chemicals from our watershed. Unfortunately, the most significant sources of these chemicals come from entities outside of the City, such as upstream industry and wastewater treatment plants. The City and its local partners will continue to advocate for eliminating these contaminants at their source, so Ann Arbor water customer do not have to carry the financial burden of removing these chemicals from their water supply. While emerging contaminants may continue to be detected, our dedicated staff are prepared to not only face these challenges, but also remain an industry leader in pioneering solutions.​​​

Can people bathe and swi​m in water containing PFAS?

The MDHHS has issued a “Do Not Eat Fish" advisory for the Huron River and advises people and their pets to avoid foam on the Huron River. Foam can have much higher amounts of PFAS than the water, and swallowing foam with PFAS could be a health risk. Swimming or bathing in water containing PFAS is not a health concern because the amount of PFAS is typically low compared to the foam. Although swallowing PFAS is the main way to get it in your body, an accidental swallow of river or lake water is not a health concern. Although current science indicates PFAS does not move easily through the skin, it's best to rinse off foam, including family pets, after contact and bathe or shower after the day's outdoor activities. None of this information changes recommendations for people's water used at home. The City of Ann Arbor installed hand-rinsing stations in close proximity to the city's canoe liveries in August 2019. These stations are in addition to hand-washing facilities available in public restrooms at the liveries.

For more information about fish advisories, see​eFish. More information about PFAS and foam is under the Surfac​e Water Workgroup section at ​

Does the City's Fire Department use firefighting foam ​​​with PFAS in it?

No, in the fall of 2018, the AAFD immediately halted the use of foam containing PFAS for traini​ng purposes and purchased an alternative option for fighting flammable liquid fires such as gasoline, oil and other hydrocarbons. The old foam was disposed of properly via a regulated waste disposal company.​​​

​​​​Additional information

To learn more about PFAS and what you can do to prevent being exposed or using products with PFAS, here a few good resources: