PFAS in Wisconsin (WI): 21 ZIPs Exceed Limits
79 ZIPs tested · 21 exceeding limits (27%) · Updated 2026-05-31
Data: EPA UCMR 3/5, SDWIS, ECHO, DOD Last verified: 2026-05-31
Wisconsin has significant PFAS contamination with 27% of tested ZIP codes exceeding federal limits. 38 Superfund sites and 3 military bases contribute to contamination. Testing your water for PFAS is recommended.
PFAS Contamination Overview
79 ZIP codes in Wisconsin have been tested for PFAS (per- and polyfluoroalkyl substances). Of those, 21 (27%) exceed federal EPA limits set in 2024.
An additional 809 ZIP codes in Wisconsin have not been tested for PFAS, representing potential undetected contamination.
Key PFAS Statistics
| Metric | Value |
|---|---|
| ZIP codes tested | 79 |
| Exceeding EPA limits | 21 (27%) |
| Superfund sites | 38 |
| Military bases with PFAS | 3 of 12 |
| Testing coverage | 9% of state ZIP codes |
| Untested ZIP codes | 809 |
PFAS Contamination Sources
Military Bases
3 military bases in Wisconsin are linked to PFAS contamination, primarily from the use of aqueous film-forming foam (AFFF) in firefighting training exercises. These foams contain high concentrations of PFOS and PFOA.
Superfund Sites
Wisconsin has 38 Superfund sites that may contribute to PFAS contamination through industrial waste, landfill leachate, and chemical manufacturing.
Other Sources
Beyond military and Superfund sites, PFAS contamination in Wisconsin also stems from:
- Industrial facilities and manufacturing plants
- Airports (AFFF use in fire training)
- Wastewater treatment plants
- Landfills (leachate from consumer products)
- Agricultural use of biosolids
What You Can Do
If your ZIP code shows PFAS contamination:
- Test your water — request a PFAS test from your utility or use a certified lab ($200-$400)
- Install filtration — reverse osmosis (RO) or granular activated carbon (GAC) systems remove 90%+ of PFAS
- Check NSF certification — look for NSF/ANSI 53 or 58 certification on filters
- Monitor utility reports — public water systems must test and report PFAS levels by 2029
- Avoid contaminated sources — if on a private well near a known contamination source, test regularly
Data Sources
- PFAS detections: EPA Unregulated Contaminant Monitoring Rule (UCMR 3/5)
- Military bases: Department of Defense PFAS Task Force
- Superfund sites: EPA Superfund PFAS
Updated as new testing data becomes available.
Worried about PFAS in your water?
PFAS contamination varies by location. Enter your ZIP code to check PFAS testing results and contamination sources near you.
Check PFAS in Your ZIP Code →Frequently Asked Questions
Is there PFAS contamination in Wisconsin?
79 ZIP codes in Wisconsin have been tested for PFAS (per- and polyfluoroalkyl substances). 21 ZIP codes (27%) exceed federal EPA limits. PFAS contamination comes from military bases, industrial sites, and consumer products.
How many ZIP codes in Wisconsin exceed PFAS limits?
21 of 79 tested ZIP codes in Wisconsin exceed EPA PFAS limits, representing 27% of tested areas. 809 ZIP codes remain untested.
What are the sources of PFAS in Wisconsin?
Major PFAS sources in Wisconsin include 3 military bases that used AFFF firefighting foam, 38 Superfund sites, industrial facilities, airports, and wastewater treatment plants.
How can I remove PFAS from my drinking water?
The most effective home filtration methods for PFAS removal are reverse osmosis (RO) systems and granular activated carbon (GAC) filters. NSF/ANSI 53 or 58 certified filters can reduce PFAS by 90%+. Pitcher filters are less effective than point-of-use RO systems.
What is the EPA limit for PFAS in drinking water?
The EPA finalized national drinking water standards in 2024: 4 parts per trillion (ppt) for PFOA and PFOS individually, and a Hazard Index for mixtures of PFHxS, PFNA, HFPO-DA, and PFBS. Public water systems must comply by 2029.