Madison tap water meets all federal and state standards for drinking water safety.
Per and Polyfluoroalkyl Substances (PFAS)
PFAS, or Per and Polyfluoroalkyl Substances, are a class of chemicals used in everything from food packaging and cookware to upholstery, clothing and firefighting foam. The chemicals do not break down in the environment and are commonly found in dust, air, soil and water. Some PFAS are found in the blood of people and animals all over the world and are present at low levels in a variety of food products and in the environment.
Different types of PFAS
Thousands of types of PFAS chemicals have been manufactured, but only a handful have been well-studied or linked to known health risks. In March of 2023, the US Environmental Protection Agency (EPA) recommended new national drinking water standards for six PFAS – PFOA, PFOS, PFHxS, PFNA, HFPO-DA (GenX), and PFBS. Previously, Wisconsin adopted state standards for two of the six PFAS chemicals.
The proposed national standards for PFOA and PFOS are 4 parts per trillion (ppt). US EPA’s proposed health-based levels for the other four PFAS are 9 ppt for PFHxS at; 10 ppt for PFNA and HFPO-DA (GenX); and 2,000 ppt for PFBS. EPA intends to finalize its national drinking water standards by the end of 2023. Until national standards are in place, Wisconsin’s adopted drinking water standards for PFOA and PFOS of 70 ppt will continue to apply.
Except for Well 15, which is currently off-line due to PFAS contamination, no Madison well exceeds any of the adopted state or proposed national drinking water standards for any PFAS. Madison Water Utility detected PFOA and/or PFOS at least once in sixteen wells. However, estimated levels of PFOA and PFOS found range from below detection (<0.4 ppt) to 1.4 ppt. PFNA and HFPO-DA (GenX) have never been found in any Madison well while PFHxS and PFBS, when found, generally range between 1 and 5 ppt.
Other types of PFAS chemicals have been found during routine testing by Madison Water Utility. However, most types are not regulated by any state or, if they are regulated, are regulated at much higher levels than PFOA and PFOS.
For example, over 90% of the PFAS detected in Well 9 is a single chemical called PFBA. The most restrictive health-based guideline for PFBA in the United States comes from the Minnesota Department of Health and is set at 7,000 parts-per-trillion. In 2022, Madison Water Utility found a total PFAS concentration in Well 9 of 36 ppt, with 33 ppt coming from PFBA. Madison Water Utility first began in-depth testing for a broad spectrum of PFAS chemicals at all city wells in 2019 at the urging of community members who petitioned the Water Utility Board for comprehensive monitoring. Madison Water Utility currently tests all active wells two times each year. Testing for PFAS is now required of all community drinking water systems in Wisconsin.
Latest PFAS Test Results
View complete 2022 Test Results
- Samples were collected in May and December of 2022 from each active well.
- Testing followed either US EPA Method 537.1, US EPA Method 533, or both methods.
Monitoring in May was part of Wisconsin DNR's Voluntary Drinking Water PFAS Sampling Project for Municipal Systems, which was funded by a US EPA grant.
Summary of Test Results
None of the up to 30 PFAS tested were found at twelve of the twenty-one wells tested
PFOA: found at eight wells ranging from 0.4 to 1.1 ppt
PFOS: found at five wells measuring between 0.6 and 1.4 ppt
- PFHxS: found at nine wells at levels ranging from 0.7 to 5.6 ppt
- PFBS: found at six wells ranging from 0.4 to 1.6 ppt
- Other PFAS found include PFBA, PFPeA, PFHxA, PFHpA, PFPeS, and 6:2 FTS
Past Testing Results
Personal Actions to Reduce Exposure
Your Guide to PFAS
Find out more information about PFAS, including State, County, and City actions, as well as actions you can take to avoid PFAS.
Your Guide to PFAS
Is Madison's water safe?
Yes, Madison tap water meets all federal and state standards for drinking water safety. If you have special circumstances or want to further purify your water, home filtration (activated carbon filters and reverse osmosis) is an option to reduce PFAS levels.
Which wells serve your home?
Which wells serve your home? Enter your address here to find out.
Fish Consumption Advisories - WI DNR
The WI Department of Natural Resources (DNR) works closely with the Department of Health Services (DHS) to issue consumption advisories for PFAS where and when necessary. Fishing is an important part of life in Wisconsin and eating fish that you catch can be part of a healthy, balanced diet. Fish are generally high in protein, contain vitamins and minerals and are the primary food source for healthy omega-3 fats. However, fish may take in pollutants from their environment and their food. In Wisconsin, the DNR regularly tests fish to determine if they contain pollutants and special fish consumption advice is issued for waterbodies where higher levels of pollutants are measured.
Following fish consumption advisories provides you the health benefits from eating fish while reducing your risk from contaminants.
Before going fishing, use the Choose Wisely guide [PDF] to determine if your fishing spot has special advice and then follow the consumption advice appropriate for the species and length of fish you'd like to eat.
You can also search for advice for any waterbody in the state using the online Find Advice tool.
Find and Use PFAS-Free Alternatives
Visit https://pfascentral.org/pfas-free-products/ for information on PFAS-free products.
PFAS Central provides current and curated information about PFAS, including press, peer-reviewed scientific articles, meetings, job listings, and consumer information. Content is provided by a partnership between the Green Science Policy Institute and the Social Science Environmental Health Research Institute at Northeastern University.
Home filtration Options
Only about one percent of the water delivered to Madison homes is used for drinking and cooking. The rest is used for flushing toilets, doing laundry, washing dishes, outdoor watering and other needs.
While the very low levels of PFAS found in Madison wells do not require large-scale wellhead treatment, Madison Water Utility often gets questions about at-home filters. It is possible to reduce PFAS chemicals in water using a home filter.
Guidance from the Wisconsin Department of Health – Home filters for PFAS.
https://www.dhs.wisconsin.gov/library/p-03012.htm (English, Spanish, Hmong)
A recent study (2020) by Duke University and North Carolina State University analyzed the effectiveness of a variety of household filters at removing PFAS from tap water.
Additional Information & PFAS Resources
WI Department of Health Services
Home Filtration (English, Spanish, & Hmong)
PFAS-free consumer products: pfascentral.org