PFAS Testing Results
What are PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a large group of human-made chemicals used since the 1940s in a wide variety of products, including stain- and water-resistant fabrics, nonstick cookware, cleaning products, paints, and firefighting foams.
PFAS are commonly used because of their ability to resist water, grease, and heat while remaining chemically stable. However, this stability also means that PFAS compounds do not break down easily in the environment and can accumulate over time in soil, water, and living organisms.
Why is PFAS testing important?
Over time, PFAS can build up in the body. This can increase the risk of health problems, such as higher cholesteral, weaker response to vaccines, thyroid problems, and lower fertility in women. Even small amounts of some PFAS in drinking water may affect health. As scientists learn more, national and state agencies are making new rules and testing standards to keep water safe.
How long has Milwaukee Water Works been testing for PFAS?
Milwaukee Water Works closely monitors water quality. Milwaukee Water Works closely monitors water quality. Since 2008, we have regularly tested for several PFAS compounds in Lake Michigan source water, at our Linnwood and Howard water purification facilities, and at two customer sites within the City of Milwaukee.
What do ‘detection limit’ and ‘reporting limit’ mean?
We send all water samples to an outside lab for testing. The lab provides a "detection limit" and a "reporting limit," which show how sure we can be about the results. It is harder to measure PFAS when there is only a very tiny amount in the water. Click here to see a diagram explaining detection and reporting limits.
Why are some results listed as “Below Reporting Limits”?
The data on this page focus on test results at or above the reporting limit (RL), because this is the level where we have the highest confidence in accuracy. If a compound is listed as “Below RL,” it does not always mean it was not detected. It means that, if present, the concentration is below the reporting limit—the lowest level the laboratory can measure with confidence.
PFAS Testing Results
The tables below show recent PFAS testing results from Milwaukee Water Works. PFAS are chemicals that can be found in water at very low levels. Testing was done on:
- Raw Lake Michigan water
- Water leaving our treatment plants
- Distribution sites throughout the city
The table columns mean the following:
- Minimum, Average, Maximum: The range of results from the tests
- Lab RL (reporting limit): The lowest level the lab can confidently measure
- Below RL: The compound was not detected or was below the lab’s measurement limit
For more information about Milwaukee Water Works PFAS testing, please leave a message on our Water Quality hotline at 414-286-2585. Be sure to include your name, address, and phone number.
Raw Lake Water PFAS Results
|
Sample Date |
PFAS Compound |
Minimum |
Average |
Maximum |
Lab RL |
Units |
|
June-2025 |
Perfluorooctanesulfonic acid (PFOS) |
1.80 |
2.00 |
2.20 |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorooctanoic acid (PFOA) |
1.90 |
2.08 |
2.20 |
1.9 |
ng/L (ppt) |
Raw Lake Water Results (Below Reporting Limits)
|
|
||||
|
Sample Date |
PFAS Compound |
Result |
Lab RL |
Units |
|
June-2025 |
Perfluorobutanoic acid (PFBA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorohexanoic acid (PFHxA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoropentanoic acid (PFPeA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoroheptanoic acid (PFHpA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
11Cl-PF3OUdS/F-53B Minor |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoro-3-methoxypropanoic acid (PFMPA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorohexanesulfonic acid (PFHxS) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorononanoic acid (PFNA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Hexafluoropropylene Oxide Dimer Acid (HFPO-DA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorobutanesulfonic acid (PFBS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorododecanoic acid (PFDoA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoroundecanoic acid (PFUnA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoropentanesulfonic acid (PFPeS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
6:2 Fluorotelomer sulfonic acid (6:2 FTS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
4:2 Fluorotelomer sulfonic acid (4:2 FTS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorodecanoic acid (PFDA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
N-ethylperfluorooctanesulfonamidoacetic acid |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoro-4-methoxybutanoic acid (PFMBA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorotetradecanoic acid (PFTeDA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
N-methylperfluorooctanesulfonamidoacetic acid |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
4,8-Dioxa-3H-Perfluorononanoic Acid (ADONA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoroheptanesulfonic acid (PFHpS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorotridecanoic acid (PFTrDA or PFTRiA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
8:2 Fluorotelomer sulfonic acid (8:2 FTS) |
Below DL |
1.9 |
ng/L (ppt) |
All PFAS samples were tested at Eurofins Eaton Analytical, LLC which holds a laboratory certification through the Wisconsin Department of Natural Resources. (Laboratory ID: 999766900)
Plant Effluent PFAS Results
|
Sample Date |
PFAS Compound |
Minimum |
Average |
Maximum |
Lab RL |
Units |
|
June-2025 |
Perfluorooctanesulfonic acid (PFOS) |
1.70 |
2.08 |
2.40 |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorooctanoic acid (PFOA) |
1.90 |
2.03 |
2.20 |
1.9 |
ng/L (ppt) |
Plant Effluent Results (Below Reporting Limits)
|
|
||||
|
Sample Date |
PFAS Compound |
Result |
Lab RL |
Units |
|
June-2025 |
Perfluorobutanoic acid (PFBA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorohexanoic acid (PFHxA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoropentanoic acid (PFPeA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoroheptanoic acid (PFHpA) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
11Cl-PF3OUdS/F-53B Minor |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoro-3-methoxypropanoic acid (PFMPA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorohexanesulfonic acid (PFHxS) |
Below RL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorononanoic acid (PFNA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Hexafluoropropylene Oxide Dimer Acid (HFPO-DA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorobutanesulfonic acid (PFBS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorododecanoic acid (PFDoA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoroundecanoic acid (PFUnA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoropentanesulfonic acid (PFPeS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
6:2 Fluorotelomer sulfonic acid (6:2 FTS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
4:2 Fluorotelomer sulfonic acid (4:2 FTS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorodecanoic acid (PFDA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
N-ethylperfluorooctanesulfonamidoacetic acid |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoro-4-methoxybutanoic acid (PFMBA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorotetradecanoic acid (PFTeDA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
N-methylperfluorooctanesulfonamidoacetic acid |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
4,8-Dioxa-3H-Perfluorononanoic Acid (ADONA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluoroheptanesulfonic acid (PFHpS) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
Perfluorotridecanoic acid (PFTrDA or PFTRiA) |
Below DL |
1.9 |
ng/L (ppt) |
|
June-2025 |
8:2 Fluorotelomer sulfonic acid (8:2 FTS) |
Below DL |
1.9 |
ng/L (ppt) |
All PFAS samples were tested at Eurofins Eaton Analytical, LLC which holds a laboratory certification through the Wisconsin Department of Natural Resources. (Laboratory ID: 999766900)
Distribution Sites PFAS Results
|
Sample Date |
PFAS Compound |
Minimum |
Average |
Maximum |
Lab RL |
Units |
|
June-2025 |
Perfluorooctanesulfonic acid (PFOS) |
1.80 |
1.95 |
2.20 |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorooctanoic acid (PFOA) |
1.90 |
2.05 |
2.10 |
2.0 |
ng/L (ppt) |
Distribution Site Results (Below Reporting Limits)
|
|
||||
|
Sample Date |
PFAS Compound |
Result |
Lab RL |
Units |
|
June-2025 |
Perfluorobutanoic acid (PFBA) |
Below RL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorohexanoic acid (PFHxA) |
Below RL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoroheptanoic acid (PFHpA) |
Below RL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoropentanoic acid (PFPeA) |
Below RL |
2.0 |
ng/L (ppt) |
|
June-2025 |
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
11Cl-PF3OUdS/F-53B Minor |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoro-3-methoxypropanoic acid (PFMPA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorohexanesulfonic acid (PFHxS) |
Below RL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorononanoic acid (PFNA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Hexafluoropropylene Oxide Dimer Acid (HFPO-DA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorobutanesulfonic acid (PFBS) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorododecanoic acid (PFDoA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoroundecanoic acid (PFUnA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoropentanesulfonic acid (PFPeS) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
6:2 Fluorotelomer sulfonic acid (6:2 FTS) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
4:2 Fluorotelomer sulfonic acid (4:2 FTS) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorodecanoic acid (PFDA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
N-ethylperfluorooctanesulfonamidoacetic acid |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoro-4-methoxybutanoic acid (PFMBA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorotetradecanoic acid (PFTeDA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
N-methylperfluorooctanesulfonamidoacetic acid |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
4,8-Dioxa-3H-Perfluorononanoic Acid (ADONA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluoroheptanesulfonic acid (PFHpS) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
Perfluorotridecanoic acid (PFTrDA or PFTRiA) |
Below DL |
2.0 |
ng/L (ppt) |
|
June-2025 |
8:2 Fluorotelomer sulfonic acid (8:2 FTS) |
Below DL |
2.0 |
ng/L (ppt) |
All PFAS samples were tested at Eurofins Eaton Analytical, LLC which holds a laboratory certification through the Wisconsin Department of Natural Resources. (Laboratory ID: 999766900)
Milwaukee Water Works 2023 PFAS Testing Results
In 2023, Milwaukee Water Works collected quarterly samples in compliance with the Environmental Protection Agency's Unregulated Contaminant Monitoring Rule (UCMR-5). The sampling dates were: 2/20/23, 6/12/23, 8/4/23 and 11/13/23. The EPA set standardized reporting limits for all 29 PFAS compounds that were tested. All results were below those reporting limits.
For more information on the EPA's Unregulated Contaminant Monitoring Rule (UCMR) 5, click here.
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