EPA UCMR 5 Data · Wisconsin

PFAS Drinking-Water Monitoring Results in Wisconsin

This page summarizes EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5, 2023–2025) drinking-water monitoring records linked to ZIP codes in Wisconsin, as processed for the PFAS Estimator national dataset. Data updated: July 2026.

32.4% of Wisconsin ZIP codes in this dataset (108 total)
had at least one regulated PFAS compound detected at or above its applicable EPA threshold (35 of 108 ZIP codes). Of those, 18 (51.4%) had more than one compound at or above threshold. This dataset includes only ZIP codes with at least one recorded PFAS detection; ZIP codes where all compounds returned non-detect are not represented.

Compounds detected in Wisconsin

Detection prevalence, exceedance, and concentration by compound, Wisconsin ZIP codes in the EPA UCMR 5 analytic dataset.
Compound Applicable threshold ZIP codes detected At/above threshold Mean detected Maximum detected
PFOA0.004 µg/L (MCL)24 (22.2% of state)24 (100.0%) — all detections at/above limit by construction0.0072 µg/L0.021 µg/L
PFOS0.004 µg/L (MCL)20 (18.5% of state)20 (100.0%) — all detections at/above limit by construction0.0122 µg/L0.031 µg/L
PFHxS0.01 µg/L (MCL)53 (49.1% of state)16 (30.2% of detected)0.0158 µg/L0.073 µg/L
PFBS2.0 µg/L (HI reference)40 (37.0% of state)not calculated¹0.0104 µg/L0.029 µg/L
Lithium7.36 µg/L (reference, not a regulatory limit)43 (39.8% of state)43 (100.0%) at/above reference16.7326 µg/L64.0 µg/L
PFPeA— (no federal limit)31 (28.7% of state)0.0094 µg/L0.024 µg/L
PFBA— (no federal limit)47 (43.5% of state)0.0284 µg/L0.28 µg/L
PFHpA— (no federal limit)10 (9.3% of state)0.0059 µg/L0.008 µg/L
6:2 FTS— (no federal limit)6 (5.6% of state)0.0251 µg/L0.035 µg/L

ZIP codes in this dataset (Wisconsin)

108 ZIP codes with at least one recorded PFAS detection. Click a ZIP code to view its full compound-level results.

Per-ZIP-code detection summary for Wisconsin
ZIP code Compounds detected At/above threshold
530054No
530121No
530221No
530248Yes (3)
530274Yes (2)
530296Yes (2)
530371No
530402Yes (1)
530444Yes (1)
530454No
530501No
530662No
530729Yes (3)
530747Yes (3)
530807Yes (3)
530814Yes (1)
530834Yes (1)
530862No
530891No
530902Yes (1)
530952Yes (1)
531201No
531224No
531461No
531474Yes (1)
531501No
531562Yes (1)
531821No
531851No
531869Yes (3)
531879Yes (3)
531889Yes (3)
535111No
535582No
535622No
535722No
535891No
535933No
537032No
537042No
537052No
537062No
537112No
537132No
537142No
537152No
537164No
537172No
537182No
537192No
537201No
537262No
538212Yes (1)
539011No
539161No
539591No
540111No
540162No
540171No
540215Yes (2)
541071No
541101No
541111No
541131No
541151No
541291No
541301No
541361No
541401No
541531No
541551No
541571No
541661No
541731No
542352Yes (2)
543131No
544016Yes (2)
544021No
544035Yes (1)
544496Yes (2)
544513Yes (1)
544671No
544747Yes (2)
544767Yes (2)
544874Yes (1)
545013Yes (1)
545381No
546016Yes (2)
546036Yes (2)
546151No
546361No
546502No
546602No
547012Yes (1)
547022Yes (1)
547032Yes (1)
547291No
547591No
548433Yes (2)
548681No
549131No
549152No
549351No
549361No
549371No
549521No
549611No
549813Yes (1)

Methodology & limitations

Results are based on EPA UCMR 5 monitoring data (2023–2025), linked to ZIP codes via Public Water System Identifier. Non-detections are not present in this analytic dataset. For each compound and ZIP code, the highest observed concentration across the monitoring period is retained; this characterizes the upper bound of observed drinking-water concentrations, not a long-term average or an individual exposure estimate. A single water system may serve multiple ZIP codes, so the same monitoring record can appear for more than one ZIP in this table. ZIP-code assignment reflects water-system service area geography and does not establish individual household exposure. Private wells are not represented unless served by a monitored public water system. PFOA and PFOS are reported by detection prevalence because the UCMR 5 reporting limit equals their federal MCL. A full PFBS Hazard Index is not calculated because co-located, same-event multi-compound readings are not retained in this dataset. Lithium has no federal Maximum Contaminant Level; 7.36 µg/L is an evidence-based reference concentration from a prospective cohort study, not a regulatory threshold.

Related links

PFAS Estimator homepage & national ZIP lookup
Full national methodology, limitations, and dataset documentation
All states & territories index

Data from the EPA Unregulated Contaminant Monitoring Rule (UCMR 5), 2023–2025. Detection does not indicate a health risk. Not medical advice. Data updated: July 2026. · EPA Source