State
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.
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
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
- Adams County 11 systems
- Ashland County 5 systems
- Barron County 14 systems
- Bayfield County 6 systems
- Brown County 22 systems
- Buffalo County 7 systems
- Burnett County 5 systems
- Calumet County 10 systems
- Chippewa County 11 systems
- Clark County 13 systems
- Columbia County 26 systems
- Crawford County 9 systems
- Dane County 46 systems
- Dodge County 24 systems
- Door County 7 systems
- Douglas County 4 systems
- Dunn County 14 systems
- Eau Claire County 16 systems
- Florence County 2 systems
- Fond du Lac County 17 systems
- Forest County 5 systems
- Grant County 28 systems
- Green County 10 systems
- Green Lake County 6 systems
- Iowa County 15 systems
- Iron County 5 systems
- Jackson County 11 systems
- Jefferson County 27 systems
- Juneau County 15 systems
- Kenosha County 37 systems
- Kewaunee County 4 systems
- La Crosse County 21 systems
- Lafayette County 9 systems
- Langlade County 3 systems
- Lincoln County 5 systems
- Manitowoc County 14 systems
- Marathon County 23 systems
- Marinette County 9 systems
- Marquette County 5 systems
- Menominee County 0 systems
- Milwaukee County 18 systems
- Monroe County 11 systems
- Oconto County 10 systems
- Oneida County 11 systems
- Outagamie County 19 systems
- Ozaukee County 48 systems
- Pepin County 3 systems
- Pierce County 11 systems
- Polk County 12 systems
- Portage County 10 systems
- Price County 5 systems
- Racine County 13 systems
- Richland County 6 systems
- Rock County 20 systems
- Rusk County 8 systems
- Sauk County 25 systems
- Sawyer County 10 systems
- Shawano County 11 systems
- Sheboygan County 17 systems
- St. Croix County 18 systems
- Taylor County 7 systems
- Trempealeau County 14 systems
- Vernon County 14 systems
- Vilas County 12 systems
- Walworth County 30 systems
- Washburn County 6 systems
- Washington County 15 systems
- Waukesha County 73 systems
- Waupaca County 12 systems
- Waushara County 8 systems
- Winnebago County 11 systems
- Wood County 13 systems
ZIP reports
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.
