PFAS in Wisconsin: 79 ZIP Codes Linked to PFAS Detections
79 ZIPs linked to PFAS sampling ยท 21 with samples above federal MCL levels (27%)
Data source: EPA UCMR 3/5, SDWIS, ECHO, DOD
ZipCheckup's PFAS reading for Wisconsin: 21 of 79 tested ZIP codes (27%) are linked to water systems with a UCMR result above the value of an EPA PFAS MCL, with compliance required from 2029. Separately, the state has 38 Superfund sites (not screened for PFAS) and 3 military sites in Department of Defense PFAS investigations.
PFAS Contamination Summary
| Metric | Value |
|---|---|
| ZIP codes with PFAS detections | 79 |
| ZIP codes with a PFAS sample above an EPA MCL level (MCL takes effect in 2029) | 21 (27%) |
| Superfund sites | 38 |
| Military bases with PFAS records in our data | 3 of 12 |
| Testing coverage | 9% of state ZIP codes |
| Untested ZIP codes | 809 |
Most Common PFAS Compounds Detected
| Compound | ZIP Codes with Detections |
|---|---|
| PFHxS | 53 |
| PFBA | 47 |
| PFBS | 40 |
| PFPeA | 31 |
| PFHxA | 28 |
| PFOA | 24 |
Worst-Affected Areas in Wisconsin
The following ZIP codes in Wisconsin are mapped to water systems with the most reported PFAS detections:
| Rank | ZIP Code | City | PFAS Types | Total Detections | Exceeds EPA Limit |
|---|---|---|---|---|---|
| 1 | 53072 | Pewaukee | 10 | 54 | Yes |
| 2 | 54474 | Rothschild | 8 | 45 | Yes |
| 3 | 53186 | Waukesha | 10 | 42 | Yes |
| 4 | 53187 | Waukesha | 10 | 41 | Yes |
| 5 | 53188 | Waukesha | 10 | 41 | Yes |
| 6 | 53029 | Hartland | 7 | 33 | No |
| 7 | 54601 | La Crosse | 7 | 32 | No |
| 8 | 54603 | La Crosse | 7 | 32 | No |
| 9 | 54476 | Schofield | 8 | 29 | Yes |
| 10 | 53024 | Grafton | 9 | 28 | Yes |
Check our PFAS map for reported detections associated with water systems serving your area.
Sources of PFAS Contamination in Wisconsin
Potential sources of PFAS in Wisconsin include:
Military Installations
3 military bases in Wisconsin are linked to PFAS contamination in these records; aqueous film-forming foam (AFFF) used in firefighting training is a possible source at military sites.
Key installations include:
- Truax Field Air National Guard Base
- Marinette/Peshtigo (Tyco Fire Products)
- General Mitchell Air National Guard Base
Superfund Sites
Wisconsin has 38 Superfund sites; this count does not establish a link to PFAS in drinking water. Sites include:
- OCONOMOWOC ELECTROPLATING CO INC
- MASTER DISPOSAL SERVICE LANDFILL
- WASTE MANAGEMENT OF WISCONSIN INC BROOKFIELD SANITARY LANDFILL
- LAUER I SANITARY LANDFILL
- MOSS AMERICAN CO INC KERR MCGEE OIL CO
Industrial and Municipal Sources
Beyond military and Superfund sites, other potential PFAS sources in Wisconsin include:
- Industrial facilities that make or use PFAS-containing products (a potential source)
- Airports that used AFFF firefighting foam
- Wastewater treatment plants, which can receive industrial discharge containing PFAS
- Landfills, which can receive PFAS-containing consumer products
Wisconsin PFAS Regulations
Wisconsin has set its own PFAS drinking water levels (enforceable standards or advisory levels, as listed below):
State limits: PFOS: 20 ppt, PFOA: 20 ppt (recommended, 2022)
Wisconsin established recommended standards and has been testing extensively.
In addition to state limits, the federal EPA PFAS rule (April 2024) sets MCLs of 4 ppt for PFOA and PFOS, with compliance required by 2029.
Testing Gaps
Only 9% of ZIP codes in Wisconsin have public PFAS testing data in our records. That leaves 809 ZIP codes with no PFAS results mapped in our records.
The EPA requires community and non-transient non-community water systems to complete initial PFAS monitoring by 2027. Until then, residents whose water has no mapped PFAS result may want to consider independent water testing or a filter certified for PFAS reduction.
What Wisconsin Residents Can Do
1. Check Your Water
Enter your ZIP code on ZipCheckup to see mapped PFAS detections and water-system violation records associated with your area.
2. Get Your Water Tested
If a water system serving your ZIP code has a PFAS detection, or no PFAS result is mapped for your area, consider a certified lab test. Look for a laboratory certified to test drinking water for PFAS using EPA Method 533 or 537.1. Before ordering, check which PFAS compounds a test measures and whether it includes the compounds regulated by EPA.
3. Install a Certified Filter
Home treatment options that can reduce some PFAS:
- Reverse osmosis (RO) systems certified to NSF 58 for PFOA/PFOS reduction
- Granular activated carbon (GAC) filters certified to NSF/ANSI 53 for PFOA/PFOS reduction can reduce those compounds
- Ion exchange systems are effective for short-chain PFAS
Use our Filter Matcher tool to find NSF-certified filters that remove PFAS.
4. Check for Lead Risk Too
Lead service line risk is separate from PFAS results and should be checked on its own. Use our Lead Risk Calculator to assess your home's lead exposure risk.
Frequently Asked Questions
How many ZIP codes in Wisconsin are linked to water-system PFAS detections?
Based on EPA data, 79 ZIP codes in Wisconsin are linked to a public water system with a PFAS detection. Of those, 21 (27%) had a PFOA or PFOS sample above the level of the 4 ppt federal MCL, which takes effect in 2029.
Is my water safe to drink in Wisconsin?
It depends on your location. 21 ZIP codes in Wisconsin had a PFAS sample above the level of a federal MCL, which takes effect in 2029. Enter your ZIP code on ZipCheckup to see your area's specific results. If PFAS are a concern, consider a filter certified for reduction of the specific PFAS in your water.
Does Wisconsin have its own PFAS limits?
Yes. Wisconsin established recommended standards and has been testing extensively. State limits: PFOS: 20 ppt, PFOA: 20 ppt (recommended, 2022). These operate alongside the federal EPA standard of 4 ppt for PFOA and PFOS.
What is the best water filter for PFAS in Wisconsin?
Reverse osmosis (RO) systems certified to NSF 58 for PFOA/PFOS reduction are among the most effective options for reducing PFAS. Granular activated carbon (GAC) filters certified to NSF 53 for PFOA/PFOS reduction also reduce PFAS. Use the ZipCheckup Filter Matcher tool to find certified filters for your specific contaminants.
Where does PFAS contamination in Wisconsin come from?
Potential PFAS source types include 3 military bases that used AFFF firefighting foam, 38 Superfund sites, industrial facilities, airports, and wastewater treatment plants. PFAS are also found in landfill leachate from consumer products containing these chemicals.
Why is there no PFAS result mapped to my area?
Public PFAS monitoring results in our records cover water systems mapped to only 9% of ZIP codes in Wisconsin. The EPA requires community and non-transient non-community water systems to complete initial PFAS monitoring by 2027 under the federal PFAS rule. Until then, you can ask a certified laboratory about PFAS testing using EPA Method 533 or 537.1 and its current price.