State system profile

PFAS in Wisconsin drinking water

Active community water systems with complete EPA UCMR 5 monitoring, summarized using yearly averages from results available through January 15, 2026.

Source EPA UCMR 5 Period 2023–2025 Systems included 174 Release ucmr5-2026-01-15-analysis-v0.2
Systems with a yearly average at or above an EPA-based study benchmark
9.8%17 of 174 active community water systems

All 174 systems had enough required samples to calculate a yearly average. 17 had at least one yearly average at or above a study benchmark; 157 did not.

EPA-based study benchmark: the unrounded cutoff this research uses to reproduce EPA’s January 2026 technical-assistance classification around the April 2024 federal levels. It is not a current standard or compliance finding and cannot determine household exposure or health risk.

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ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.

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Compound summary

System counts in Wisconsin

Each count shows how many included water systems had a yearly average at or above the named study benchmark.

Community water systems with yearly averages at or above the EPA-based study benchmarks used in the January 2026 research release for Wisconsin.
Study benchmarkSystems at or above benchmarkWater systems includedPercent
PFOA: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt)121746.9%
PFOS: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt)111746.3%
PFHxS: 15 ppt study benchmark (reproduces EPA classification around 10 ppt)31741.7%
PFNA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt)01740.0%
HFPO-DA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt)01740.0%
Hazard Index: 1.5 study benchmark with at least two detected components (reproduces EPA classification around 1)31741.7%
System directory

Community water systems with complete monitoring

“Complete monitoring” means at least one sampling location had all required samples needed for a yearly average. Each PWSID appears once, preventing double counting across ZIP associations.

Active community water systems with complete UCMR 5 monitoring in Wisconsin.
Public water systemPWSIDPopulation servedPrimary sourceSampling locationsStudy benchmark result
ALLOUEZ WATERWORKSWI405045513,923Surface water purchased1Below all study benchmarks
ALTOONA WATERWORKSWI61802809,627Ground water6Below all study benchmarks
ANTIGO WATERWORKSWI73400867,780Ground water1Below all study benchmarks
APPLETON WATERWORKSWI445033374,511Surface water1Below all study benchmarks
ARENA WATERWORKSWI1250073877Ground water1Below all study benchmarks
ASHWAUBENON WATERWORKSWI405045617,730Surface water purchased1Below all study benchmarks
BALDWIN WATERWORKSWI65601194,440Ground water2Below all study benchmarks
BARABOO WATERWORKSWI157008512,703Ground water5Below all study benchmarks
BARRON LIGHT & WATER DEPTWI60301253,423Ground water4Below all study benchmarks
BEAVER DAM WATER UTILITYWI114005916,200Ground water1Below all study benchmarks
BELLEVUE WATERWORKSWI405045916,715Surface water purchased1Below all study benchmarks
BELOIT CITY OFWI154011236,677Ground water7Below all study benchmarks
BERLIN WATERWORKSWI42402165,524Ground water3Below all study benchmarks
BLACK RIVER FALLS WATERWORKSWI62702443,608Ground water4Below all study benchmarks
BLOOMINGTON WATERWORKSWI1220085682Ground water1Below all study benchmarks
BRILLION WATERWORKSWI40802213,262Ground water3Below all study benchmarks
BROOKFIELD WATER UTILITYWI268025329,070Ground water17Below all study benchmarks
BROWN DEER WATERWORKSWI241055612,741Surface water purchased1Below all study benchmarks
BURLINGTON WATERWORKSWI252017711,043Ground water5Below all study benchmarks
CALEDONIA WATER UTILITY - VILLAGE OFWI252018421,819Surface water purchased2Below all study benchmarks
CEDARBURG L & W COMMISSIONWI246010812,500Ground water4Below all study benchmarks
CHIPPEWA FALLS WATERWORKSWI609045613,375Ground water2Below all study benchmarks
CLINTON WATERWORKS, WIWI15401142,119Ground water2Below all study benchmarks
CLINTONVILLE UTILITIESWI46903914,635Ground water3Below all study benchmarks
COLUMBUS WATER & LIGHT DEPARTMENTWI11100385,173Ground water2Below all study benchmarks
COMBINED LOCKS WATERWORKSWI44504093,609Ground water purchased1Below all study benchmarks
COTTAGE GROVE WATERWORKSWI11302189,345Ground water3Below all study benchmarks
CROSS PLAINS WATERWORKSWI11302194,100Ground water3Below all study benchmarks
CUDAHY WATERWORKSWI241016918,659Surface water1Below all study benchmarks
DARBOY SANITARY DIST 1WI445011713,024Ground water2Below all study benchmarks
DE PERE WATER DEPARTMENTWI405045325,660Surface water purchased1Below all study benchmarks
DEFOREST WATERWORKSWI113022110,500Ground water4Below all study benchmarks
DELAVAN WATERWORKSWI26501139,028Ground water3Below all study benchmarks
DENMARK WATERWORKSWI40503512,684Surface water purchased2Below all study benchmarks
EAST TROY WATERWORKSWI26501235,054Ground water4Below all study benchmarks
EAU CLAIRE WATERWORKSWI618023070,587Ground water1Below all study benchmarks
EDGERTON WATERWORKSWI15401195,512Ground water3Below all study benchmarks
ELKHORN WATERWORKSWI265006210,317Ground water3Below all study benchmarks
ELLSWORTH WATERWORKSWI64802393,304Ground water3Below all study benchmarks
EVANSVILLE WATERWORKSWI15400475,703Ground water2Below all study benchmarks
FITCHBURG UTILITY DIST 1WI113023124,500Ground water4Below all study benchmarks
FOND DU LAC WATERWORKSWI420046944,678Ground water4Below all study benchmarks
FORT ATKINSON WATERWORKSWI128010312,390Ground water4Below all study benchmarks
FORT MCCOY NORTH POSTWI642030210,000Ground water6Below all study benchmarks
FOX CROSSING UTILITIES EAST-FORMERLY MENASHA TN OFWI471045310,927Surface water purchased2Below all study benchmarks
FOX CROSSING UTILITIES WEST-FORMERLY MENASHA TN OFWI471035814,000Ground water4Below all study benchmarks
FOX POINT WATERWORKSWI24105846,808Surface water purchased1Below all study benchmarks
FRANKLIN WATER UTILITYWI241056322,500Surface water purchased1Below all study benchmarks
GERMANTOWN WATER UTILITYWI267010520,027Ground water6Below all study benchmarks
GLENDALE WATERWORKSWI241016812,883Surface water purchased1Below all study benchmarks
GRAFTON WATERWORKSWI246011112,269Ground water6Below all study benchmarks
GRAND CHUTE TN SAN DIST 1WI445042921,583Surface water purchased1Below all study benchmarks
GREEN BAY WATERWORKSWI4050356107,369Surface water1Below all study benchmarks
GREENDALE WATERWORKSWI241057114,393Surface water purchased1Below all study benchmarks
GREENVILLE SANITARY DISTWI445027811,340Ground water4Below all study benchmarks
HARTFORD WATERWORKS, WIWI267011015,805Ground water5At or above a study benchmark
HARTLAND WATERWORKSWI26802059,212Ground water5At or above a study benchmark
HILBERT WATERWORKSWI40802691,176Ground water2Below all study benchmarks
HOLMEN WATERWORKSWI632030610,147Ground water4Below all study benchmarks
HORICON WATERWORKSWI11401463,682Ground water3Below all study benchmarks
HOWARD WATERWORKSWI405046821,133Surface water purchased2Below all study benchmarks
HUDSON WATERWORKSWI656008718,558Ground water7Below all study benchmarks
JACKSON WATERWORKSWI26701117,844Ground water4Below all study benchmarks
JANESVILLE WATER UTILITYWI154012764,415Ground water3Below all study benchmarks
JEFFERSON WATERWORKSWI12801047,926Ground water3Below all study benchmarks
KAUKAUNA UTILITIESWI445033617,493Ground water3Below all study benchmarks
KENOSHA WATER UTILITYWI230004699,218Surface water1Below all study benchmarks
KESHENA0552955083,960Ground water1Below all study benchmarks
KEWASKUM WATERWORKSWI26701124,309Ground water4At or above a study benchmark
KIEL WATERWORKSWI43604273,932Ground water4Below all study benchmarks
KIMBERLY WATERWORKSWI44503427,608Ground water3Below all study benchmarks
KRONENWETTER WATER & SEWER UTILITYWI73717006,931Ground water2Below all study benchmarks
LA CROSSE WATERWORKSWI632030953,000Ground water10At or above a study benchmark
LAKE GENEVA UTILITY COMMISSIONWI26500667,107Ground water2At or above a study benchmark
LAKE HALLIE WATERWORKS VILLAGE OFWI60908496,701Ground water4Below all study benchmarks
LAKE MILLS WATERWORKSWI12801086,211Ground water3Below all study benchmarks
LAWRENCE WATERWORKSWI40516255,398Surface water purchased1Below all study benchmarks
LEDGEVIEW TN SANITARY DIST 2WI40514187,602Surface water purchased2Below all study benchmarks
LITTLE CHUTE WATERWORKSWI445033812,168Ground water3Below all study benchmarks
MADISON WATER UTILITYWI1130224272,000Ground water20Below all study benchmarks
MANITOWOC WATERWORKSWI436036434,500Surface water1Below all study benchmarks
MARINETTE WATERWORKSWI438039510,968Surface water1Below all study benchmarks
MARSHALL WATERWORKSWI11302373,862Ground water3Below all study benchmarks
MARSHFIELD UTILITIESWI772016518,815Ground water3At or above a study benchmark
MAYVILLE WATERWORKSWI11400575,112Ground water4Below all study benchmarks
MCFARLAND WATERWORKSWI11302419,676Ground water3Below all study benchmarks
MEDFORD WATERWORKSWI86101254,318Ground water6Below all study benchmarks
MENASHA ELEC & WATER UTILWI471033415,144Surface water1Below all study benchmarks
MENOMONIE WATERWORKSWI617026815,950Ground water3Below all study benchmarks
MEQUON WATER UTILITYWI246011211,152Surface water purchased2Below all study benchmarks
MERRILL WATERWORKSWI73501239,661Ground water2Below all study benchmarks
MIDDLETON WATERWORKSWI113024223,868Ground water6Below all study benchmarks
MILTON WATERWORKSWI15401305,588Ground water4Below all study benchmarks
MILWAUKEE WATERWORKSWI2410100626,000Surface water2Below all study benchmarks
MONROE WATERWORKSWI123007810,780Ground water5Below all study benchmarks
MT HOREB WATERWORKSWI11302477,756Ground water4Below all study benchmarks
MUKWONAGO WATERWORKSWI26802098,190Ground water2Below all study benchmarks
MUSKEGO WATER UTILITYWI26817418,150Ground water8Below all study benchmarks
NEENAH WATERWORKSWI471034827,506Surface water1Below all study benchmarks
NEW BERLIN WATER UTILITYWI268021727,899Surface water purchased1Below all study benchmarks
NEW LONDON WATERWORKSWI46903987,187Ground water7Below all study benchmarks
NEW RICHMOND WATERWORKSWI656012610,824Ground water5Below all study benchmarks
NORTH FOND DU LAC WATERWORKSWI42004055,414Ground water1Below all study benchmarks
NORTH SHORE WATER COMMISSIONWI241351535,598Surface water1Below all study benchmarks
OAK CREEK WATERWORKSWI241017232,104Surface water1Below all study benchmarks
OCONOMOWOC WATERWORKSWI268022715,805Ground water4Below all study benchmarks
OMRO WATERWORKSWI47103573,629Ground water3Below all study benchmarks
ONALASKA WATERWORKSWI632032718,000Ground water4Below all study benchmarks
OREGON WATERWORKSWI113025111,200Ground water3Below all study benchmarks
OSHKOSH WATERWORKSWI471045763,000Surface water1Below all study benchmarks
PALMYRA WATERWORKSWI12801121,756Ground water2At or above a study benchmark
PESHTIGO WATERWORKSWI43804423,420Ground water3Below all study benchmarks
PEWAUKEE CITY WATER AND SEWER UTILITYWI26802148,671Ground water8At or above a study benchmark
PLATTEVILLE WATERWORKSWI122011512,268Ground water3Below all study benchmarks
PLEASANT PRAIRIE WATER UTILITYWI230016710,754Surface water purchased1Below all study benchmarks
PLOVER WATERWORKSWI750072613,486Ground water3Below all study benchmarks
PLYMOUTH UTILITIESWI46004468,964Ground water7Below all study benchmarks
PORT WASHINGTON WATERWORKSWI246005412,853Surface water1Below all study benchmarks
PORTAGE WATERWORKSWI111003910,437Ground water2Below all study benchmarks
PRAIRIE DU SAC WATERWORKSWI15701004,006Ground water2Below all study benchmarks
PRESCOTT WATERWORKSWI64802434,258Ground water2At or above a study benchmark
PULASKI WATERWORKSWI40503554,040Ground water2Below all study benchmarks
RACINE WATERWORKSWI2520062105,100Surface water1Below all study benchmarks
REEDSBURG WATERWORKSWI15701029,984Ground water5Below all study benchmarks
RHINELANDER WATER & WASTEWATERWI74401268,234Ground water2At or above a study benchmark
RIB MOUNTAIN SANITARY DISTWI73706606,398Ground water4At or above a study benchmark
RICE LAKE WATERWORKSWI60301389,012Ground water4Below all study benchmarks
RICHLAND CENTER WATERWORKSWI15300685,100Ground water3Below all study benchmarks
RIPON WATER UTILITYWI42004767,716Ground water4Below all study benchmarks
RIVER FALLS WATERWORKSWI648024616,000Ground water5Below all study benchmarks
SAUK CITY WATERWORKSWI15701053,518Ground water2Below all study benchmarks
SAUKVILLE WATERWORKSWI24601344,268Ground water5At or above a study benchmark
SCHOFIELD WATERWORKSWI73701622,205Ground water2At or above a study benchmark
SEYMOUR WATERWORKSWI44503373,601Ground water2Below all study benchmarks
SHAWANO LK SAN DIST 1WI45904574,950Ground water3Below all study benchmarks
SHAWANO WATERWORKSWI45904569,610Ground water3Below all study benchmarks
SHEBOYGAN FALLS UTILITIESWI46004558,687Surface water purchased1Below all study benchmarks
SHEBOYGAN TN WATERWORKSWI46004034,596Ground water3Below all study benchmarks
SHEBOYGAN WATER UTILITIESWI460035449,931Surface water1Below all study benchmarks
SHOREWOOD WATERWORKSWI241060713,535Surface water purchased1Below all study benchmarks
SHULLSBURG WATERWORKSWI13300761,222Ground water2Below all study benchmarks
SLINGER WATER UTILITYWI26701165,659Ground water3Below all study benchmarks
SOUTH MILWAUKEE WATERWORKSWI241014421,340Surface water1Below all study benchmarks
SOUTH-CENTRAL WATER SYSTEM0552950032,805Ground water1Below all study benchmarks
SPARTA WATERWORKSWI642029710,025Ground water5Below all study benchmarks
STANLEY WATERWORKSWI60904623,500Ground water3Below all study benchmarks
STEVENS POINT WATERWORKSWI750014126,717Ground water2Below all study benchmarks
STOUGHTON WATERWORKSWI113007813,078Ground water4Below all study benchmarks
STURGEON BAY WATERWORKSWI41505269,700Ground water5At or above a study benchmark
SUAMICO WATERWORKSWI40510314,697Ground water2Below all study benchmarks
SUN PRAIRIE UTILITIESWI113025839,300Ground water7Below all study benchmarks
SUPERIOR WATER LIGHT & POWER COMPANYWI816014726,084Surface water1Below all study benchmarks
SUSSEX VILLAGE HALL & WATER UTILITYWI268023311,750Ground water4Below all study benchmarks
TOMAH WATERWORKSWI64202549,192Ground water5Below all study benchmarks
TOMAHAWK WATERWORKSWI73501273,180Ground water2At or above a study benchmark
TWO RIVERS WATERWORKSWI436043611,270Surface water1Below all study benchmarks
UNION GROVE WATERWORKSWI25202004,900Ground water3Below all study benchmarks
VERONA WATERWORKSWI113025914,030Ground water5Below all study benchmarks
VIROQUA WATERWORKSWI66302634,362Ground water3Below all study benchmarks
WATERFORD WATERWORKSWI25202025,368Ground water3Below all study benchmarks
WATERTOWN WATERWORKSWI128004423,945Ground water3Below all study benchmarks
WAUKESHA WATER UTILITYWI268023870,718Surface water purchased7Below all study benchmarks
WAUNAKEE WATERWORKSWI113026514,879Ground water4Below all study benchmarks
WAUPACA WATERWORKSWI46904026,062Ground water6At or above a study benchmark
WAUPUN CORRECTIONAL INSTWI11401423,706Ground water2Below all study benchmarks
WAUPUN UTILITIESWI11401318,056Ground water1Below all study benchmarks
WAUSAU WATERWORKSWI737010239,994Ground water2Below all study benchmarks
WAUWATOSA WATERWORKSWI241059649,064Surface water purchased1Below all study benchmarks
WEST ALLIS WATERWORKSWI241059563,240Surface water purchased1Below all study benchmarks
WEST SALEM WATERWORKSWI63203345,045Ground water3Below all study benchmarks
WESTON MUNICIPAL UTILITIESWI737016316,000Ground water7At or above a study benchmark
WHITEFISH BAY WATERWORKSWI241059714,272Surface water purchased1Below all study benchmarks
WHITEWATER WATERWORKSWI265005614,000Ground water5Below all study benchmarks
WIS RAPIDS WATER WORKS & LIGHTING COMMWI772010820,000Ground water1Below all study benchmarks
How the count works

What is included

Each active community water system with enough required samples for a yearly average is counted once, even if it is linked with several ZIP codes. This does not mean every home was tested. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Wisconsin's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.

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Related links

PFAS Estimator system lookupNational state comparison tableFull methodology and limitationsCurrent EPA UCMR 5 Data FinderOfficial state and territory drinking-water programs