Perfluorinated Compounds

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.

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. Most drinking water regulations focus on two types of PFAS compounds – PFOA and PFOS.  Both have been phased out of use in the United States.

Madison Water Utility detected PFOA and/or PFOS at least once in sixteen wells. The estimated level of PFOA + PFOS found ranged from 0.4 to 3.4 parts per trillion. Wisconsin DNR recently set a safe drinking water limit of 70 parts per trillion for PFOA and PFOS in Wisconsin.  This level matches a federal health advisory level that was established by US EPA in 2016.

Madison Water Utility found a broad range of other types of PFAS chemicals during its testing. Most types are not regulated by any state. Others are regulated at much higher levels than PFOA and PFOS.

For example, over 80% 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. Madison Water Utility found a total PFAS concentration in Well 9 of 47 ppt, with 37 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. Testing for PFAS is now required of all community drinking water systems in Wisconsin. 

Latest PFAS Test Results

View complete 2022 Test Results

Background

  • Samples were collected in May from each active well (18) and subjected to analysis by US EPA Method 537.1 at the WI State Lab of Hygiene

  • Test results are from the WI DNR Voluntary Drinking Water PFAS Sampling Project for Municipal Systems – funded by a US EPA grant.

  • Reporting limits (RL) vary by PFAS but generally are below 1 part per trillion (ppt) for some PFAS and below 2 ppt for others.

Summary of Test Results

  • None of the 18 PFAS tested were found at ten of the eighteen wells tested

  • PFOS (RL: <1 ppt) was detected at a single well (#16) and PFOA (RL: <2 ppt) was not detected at any of the 18 wells tested

  • PFHxS (RL: <1 ppt) was most commonly detected; it was found at eight wells at levels ranging from 0.96 to 5.51 ppt

  • PFBS (RL: <1 ppt) was found at three wells (#6, #9, and #14) ranging from 1.02 to 1.77 ppt while PFHxA (RL <2 ppt) was found at one well (#14) and measured 2.08 ppt

Past Testing Results 

Personal Actions to Reduce Exposure

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.

  • 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

Water Quality

Water Quality