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Wisconsin: drinking water records

EPA lists 1,051 community water systems serving homes in Wisconsin. 196 took part in EPA's national PFAS survey (UCMR 5), and 52 found at least one PFAS above the level laboratories can measure.

In focus1,051community water systems
Public records. Clearer context.

Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages

0
ZIP reports published
1,051
community water systems
375
systems with a health-based violation since 2016
79
systems that reached the lead action level since 2016

PFAS in EPA’s final survey

52 of the 196 Wisconsin systems in EPA’s national PFAS survey found at least one PFAS, and 18 had a PFOA or PFOS yearly average at or above EPA’s limit. See Wisconsin’s PFAS results by system and compound.

Counties

ZIP reports

Beyond the Wisconsin overview

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Sources

EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Database prepared 2026-09-03.

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