PFAS in Wisconsin drinking water
EPA's final UCMR 5 data covers 202 public water systems in Wisconsin, serving about 3.7 million people. PFAS turned up in 52 of them (26%). 20 averaged above at least one EPA limit at a sampling point, affecting about 244,420 people.
Highest PFOA and PFOS averages among systems serving 1,000 or more: Saukville Waterworks (2.1 / 30.5 ppt), Prairie Du Chien Waterworks (0.0 / 25.0 ppt), Tomahawk Waterworks (20.0 / 0.0 ppt), Weston Municipal Utilities (5.5 / 10.8 ppt) and Kewaskum Waterworks (13.5 / 0.0 ppt).
Every tested system in Wisconsin
Largest first. PFOA and PFOS columns show the average at each system's worst sampling point; EPA's limit for each is 4 ppt. Filter by name:
| Water system | People | PFOA | PFOS | PFAS found | Result |
|---|---|---|---|---|---|
| Milwaukee Waterworks · Milwaukee | 626,000 | - | - | 0 | None found |
| Madison Water Utility | 272,000 | - | - | 2 | Below limits |
| Green Bay Waterworks · Green Bay | 107,369 | - | - | 0 | None found |
| Racine Waterworks · Racine | 105,100 | - | - | 0 | None found |
| Kenosha Water Utility · Kenosha | 99,218 | - | - | 0 | None found |
| Appleton Waterworks · Appleton | 74,511 | - | - | 1 | Below limits |
| Waukesha Water Utility | 70,718 | - | - | 0 | None found |
| Eau Claire Waterworks | 70,587 | - | - | 2 | Above limit |
| Janesville Water Utility | 64,415 | - | - | 0 | None found |
| West Allis Waterworks · West Allis | 63,240 | - | - | 0 | None found |
| Oshkosh Waterworks · Oshkosh | 63,000 | - | - | 0 | None found |
| La Crosse Waterworks | 53,000 | 4.8 | 4.9 | 7 | Above limit |
| Sheboygan Water Utilities · Sheboygan | 49,931 | - | - | 0 | None found |
| Wauwatosa Waterworks · Wauwatosa | 49,064 | - | - | 0 | None found |
| Fond Du Lac Waterworks | 44,678 | - | - | 0 | None found |
| Wausau Waterworks | 39,994 | - | - | 1 | Below limits |
| Sun Prairie Utilities | 39,300 | - | - | 0 | None found |
| City of Beloit | 36,677 | - | - | 1 | Below limits |
| North Shore Water Commission · Milwaukee | 35,598 | - | - | 0 | None found |
| Manitowoc Waterworks · Manitowoc | 34,500 | - | - | 0 | None found |
| Oak Creek Waterworks · Oak Creek | 32,104 | - | - | 0 | None found |
| West Bend Waterworks | 31,752 | 3.2 | - | 2 | Sample at limit |
| Brookfield Water Utility | 29,070 | - | - | 4 | Below limits |
| New Berlin Water Utility | 27,899 | - | - | 0 | None found |
| Neenah Waterworks · Neenah | 27,506 | - | - | 0 | None found |
| Stevens Point Waterworks · Stevens Point | 26,717 | - | - | 0 | None found |
| Superior Water Light & Power Company · Superior | 26,084 | - | - | 0 | None found |
| De Pere Water Department · De Pere | 25,660 | - | - | 0 | None found |
| Fitchburg Utility Dist 1 · Fitchburg | 24,500 | - | - | 0 | None found |
| Watertown Waterworks · Watertown | 23,945 | - | - | 0 | None found |
| Middleton Waterworks | 23,868 | - | - | 0 | None found |
| Menomonee Falls Ww - Surface Water · Menomonee Falls | 23,867 | - | - | 0 | None found |
| Franklin Water Utility · Franklin | 22,500 | - | - | 0 | None found |
| Village of Caledonia Water Utility - · Caledonia | 21,819 | - | - | 0 | None found |
| Grand Chute Tn San Dist 1 · Grand Chute | 21,583 | - | - | 0 | None found |
| South Milwaukee Waterworks · South Milwaukee | 21,340 | - | - | 0 | None found |
| Howard Waterworks · Green Bay | 21,133 | - | - | 0 | None found |
| Germantown Water Utility · Germantown | 20,027 | - | - | 0 | None found |
| Wis Rapids Water Works & Lighting Comm | 20,000 | - | - | 0 | None found |
| Marshfield Utilities · Marshfield | 18,815 | - | 13.0 | 7 | Above limit |
| Cudahy Waterworks · Cudahy | 18,659 | - | - | 0 | None found |
| Hudson Waterworks | 18,558 | - | - | 1 | Below limits |
| Onalaska Waterworks · Onalaska | 18,000 | - | - | 1 | Below limits |
| Ashwaubenon Waterworks · Ashwaubenon | 17,730 | - | - | 0 | None found |
| Kaukauna Utilities | 17,493 | - | - | 0 | None found |
| Bellevue Waterworks · Green Bay | 16,715 | - | - | 0 | None found |
| Beaver Dam Water Utility · Beaver Dam | 16,200 | - | - | 0 | None found |
| River Falls Waterworks · River Falls | 16,000 | - | - | 0 | None found |
| Weston Municipal Utilities | 16,000 | 5.5 | 10.8 | 8 | Above limit |
| Menomonie Waterworks | 15,950 | - | - | 0 | None found |
| Hartford Waterworks · Hartford | 15,805 | 1.3 | 1.0 | 4 | Sample at limit |
| Oconomowoc Waterworks | 15,805 | - | - | 2 | Below limits |
| Menasha Elec & Water Util · Menasha | 15,144 | - | - | 0 | None found |
| Waunakee Waterworks | 14,879 | - | - | 0 | None found |
| Greendale Waterworks · Greendale | 14,393 | - | - | 0 | None found |
| Whitefish Bay Waterworks · Milwaukee | 14,272 | - | - | 0 | None found |
| Verona Waterworks · Verona | 14,030 | - | - | 1 | Below limits |
| Whitewater Waterworks · Whitewater | 14,000 | - | - | 0 | None found |
| Fox Crossing Utilities West-formerly Menasha Tn of · Neenah | 14,000 | - | - | 0 | None found |
| Allouez Waterworks · Green Bay | 13,923 | - | - | 0 | None found |
| Shorewood Waterworks · Shorewood | 13,535 | - | - | 0 | None found |
| Plover Waterworks · Plover | 13,486 | - | - | 1 | Below limits |
| Chippewa Falls Waterworks | 13,375 | - | - | 1 | Below limits |
| Stoughton Waterworks · Stoughton | 13,078 | - | - | 1 | Below limits |
| Darboy Sanitary Dist 1 · Appleton | 13,024 | - | - | 0 | None found |
| Glendale Waterworks · Glendale | 12,883 | - | - | 0 | None found |
| Port Washington Waterworks · Port Washington | 12,853 | - | - | 0 | None found |
| Brown Deer Waterworks · Brown Deer | 12,741 | - | - | 0 | None found |
| Baraboo Waterworks · Baraboo | 12,703 | - | - | 0 | None found |
| Cedarburg L & W Commission · Cedarburg | 12,500 | - | - | 0 | None found |
| Fort Atkinson Waterworks | 12,390 | - | - | 0 | None found |
| Grafton Waterworks · Grafton | 12,269 | - | - | 0 | None found |
| Platteville Waterworks · Platteville | 12,268 | - | - | 0 | None found |
| Little Chute Waterworks | 12,168 | - | - | 0 | None found |
| Sussex Village Hall & Water Utility | 11,750 | - | - | 0 | None found |
| Greenville Sanitary Dist · Greenville | 11,340 | - | - | 0 | None found |
| Two Rivers Waterworks · Two Rivers | 11,270 | - | - | 0 | None found |
| Oregon Waterworks · Oregon | 11,200 | - | - | 0 | None found |
| Mequon Water Utility · Mequon | 11,152 | - | - | 0 | None found |
| Burlington Waterworks · Burlington | 11,043 | - | - | 0 | None found |
| Marinette Waterworks · Marinette | 10,968 | - | - | 0 | None found |
| Fox Crossing Utilities East-formerly Menasha Tn of · Neenah | 10,927 | - | - | 0 | None found |
| New Richmond Waterworks · New Richmond | 10,824 | - | - | 1 | Below limits |
| Monroe Waterworks · Monroe | 10,780 | - | - | 0 | None found |
| Pleasant Prairie Water Utility · Pleasant Prairie | 10,754 | - | - | 0 | None found |
| Deforest Waterworks | 10,500 | - | - | 0 | None found |
| Portage Waterworks · Portage | 10,437 | - | - | 1 | Below limits |
| Elkhorn Waterworks · Elkhorn | 10,317 | - | - | 0 | None found |
| Holmen Waterworks | 10,147 | - | - | 1 | Below limits |
| Sparta Waterworks | 10,025 | - | - | 0 | None found |
| Fort Mccoy North Post | 10,000 | - | - | 0 | None found |
| Reedsburg Waterworks | 9,984 | - | - | 1 | Below limits |
| Sturgeon Bay Waterworks · Sturgeon Bay | 9,700 | - | 4.2 | 2 | Above limit |
| Mcfarland Waterworks · Mcfarland | 9,676 | - | - | 1 | Below limits |
| Merrill Waterworks · Merrill | 9,661 | - | - | 0 | None found |
| Altoona Waterworks · Altoona | 9,627 | - | - | 0 | None found |
| Shawano Waterworks · Shawano | 9,610 | - | - | 0 | None found |
| Cottage Grove Waterworks · Cottage Grove | 9,345 | - | - | 0 | None found |
| Hartland Waterworks · Hartland | 9,212 | 4.4 | 4.4 | 7 | Above limit |
| Tomah Waterworks | 9,192 | - | - | 3 | Below limits |
| Delavan Waterworks · Delavan | 9,028 | - | - | 0 | None found |
| Rice Lake Waterworks · Rice Lake | 9,012 | - | - | 0 | None found |
| Plymouth Utilities · Plymouth | 8,964 | - | - | 0 | None found |
| Sheboygan Falls Utilities · Sheboygan Falls | 8,687 | - | - | 0 | None found |
| Pewaukee City Water and Sewer Utility · Pewaukee | 8,671 | 4.2 | 6.0 | 10 | Above limit |
| Monona Waterworks · Monona | 8,624 | - | - | 5 | Below limits |
| Rhinelander Water & Wastewater · Rhinelander | 8,234 | 6.2 | - | 4 | Above limit |
| Mukwonago Waterworks | 8,190 | - | - | 0 | None found |
| Pewaukee Village Waterworks · Pewaukee | 8,166 | - | - | 2 | Below limits |
| Muskego Water Utility | 8,150 | - | - | 0 | None found |
| Waupun Utilities · Waupun | 8,056 | - | - | 0 | None found |
| Ashland Water Utility · Ashland | 8,000 | - | - | 0 | None found |
| Jefferson Waterworks · Jefferson | 7,926 | - | - | 0 | None found |
| Jackson Waterworks · Jackson | 7,844 | - | - | 0 | None found |
| Antigo Waterworks · Antigo | 7,780 | - | - | 0 | None found |
| Mt Horeb Waterworks · Mount Horeb | 7,756 | - | - | 2 | Below limits |
| Ripon Water Utility | 7,716 | - | - | 0 | None found |
| Kimberly Waterworks · Kimberly | 7,608 | - | - | 0 | None found |
| Ledgeview Tn Sanitary Dist 2 · De Pere | 7,602 | - | - | 0 | None found |
| New London Waterworks · New London | 7,187 | - | - | 1 | Below limits |
| Lake Geneva Utility Commission | 7,107 | 4.5 | - | 3 | Above limit |
| Kronenwetter Water & Sewer Utility · Kronenwetter | 6,931 | - | - | 0 | None found |
| Fox Point Waterworks · Fox Point | 6,808 | - | - | 0 | None found |
| Village of Lake Hallie Waterworks · Chippewa Falls | 6,701 | - | - | 0 | None found |
| Town of Brookfield San Dist 4 · Brookfield | 6,419 | - | - | 2 | Below limits |
| Rib Mountain Sanitary Dist · Wausau | 6,398 | 4.8 | 8.5 | 7 | Above limit |
| Lake Mills Waterworks · Lake Mills | 6,211 | - | - | 0 | None found |
| Waupaca Waterworks | 6,062 | - | 4.2 | 3 | Above limit |
| Prairie Du Chien Waterworks | 6,005 | - | 25.0 | 2 | Above limit |
| Evansville Waterworks | 5,703 | - | - | 0 | None found |
| Slinger Water Utility · Slinger | 5,659 | - | - | 3 | Below limits |
| Milton Waterworks · Milton | 5,588 | - | - | 0 | None found |
| Berlin Waterworks · Berlin | 5,524 | - | - | 0 | None found |
| Edgerton Waterworks · Edgerton | 5,512 | - | - | 0 | None found |
| Harrison Utilities - Fka Waverly Sd · Menasha | 5,500 | - | - | 1 | Below limits |
| Ho Chunk Casino | 5,486 | - | - | 0 | None found |
| North Fond Du Lac Waterworks · North Fond Du Lac | 5,414 | - | - | 0 | None found |
| Lawrence Waterworks · De Pere | 5,398 | - | - | 0 | None found |
| Waterford Waterworks | 5,368 | - | - | 0 | None found |
| Columbus Water & Light Department | 5,173 | - | - | 0 | None found |
| Mayville Waterworks | 5,112 | - | - | 0 | None found |
| Richland Center Waterworks · Richland Center | 5,100 | - | - | 0 | None found |
| East Troy Waterworks · East Troy | 5,054 | - | - | 1 | Below limits |
| West Salem Waterworks · West Salem | 5,045 | - | - | 0 | None found |
| Shawano Lk San Dist 1 · Shawano | 4,950 | - | - | 1 | Below limits |
| Union Grove Waterworks · Union Grove | 4,900 | - | - | 0 | None found |
| Suamico Waterworks · Suamico | 4,697 | - | - | 0 | None found |
| Clintonville Utilities | 4,635 | - | - | 0 | None found |
| Sheboygan Tn Waterworks · Sheboygan | 4,596 | - | - | 4 | Above limit |
| Dodgeville Waterworks · Dodgeville | 4,583 | - | - | 0 | None found |
| Oconto Waterworks · Oconto | 4,583 | - | - | 0 | None found |
| Mauston Waterworks · Mauston | 4,456 | - | - | 0 | None found |
| Baldwin Waterworks · Baldwin | 4,440 | - | - | 0 | None found |
| Viroqua Waterworks | 4,362 | - | - | 0 | None found |
| Medford Waterworks | 4,318 | 2.1 | - | 3 | Sample at limit |
| Kewaskum Waterworks · Kewaskum | 4,309 | 13.5 | - | 2 | Above limit |
| Saukville Waterworks · Saukville | 4,268 | 2.1 | 30.5 | 9 | Above limit |
| Prescott Waterworks · Prescott | 4,258 | 9.4 | - | 6 | Above limit |
| Chilton Waterworks · Chilton | 4,191 | - | - | 0 | None found |
| Cross Plains Waterworks · Cross Plains | 4,100 | - | - | 0 | None found |
| Village of Bloomfield · Pell Lake | 4,071 | - | - | 0 | None found |
| Pulaski Waterworks · Pulaski | 4,040 | - | - | 0 | None found |
| Prairie Du Sac Waterworks | 4,006 | - | - | 0 | None found |
| Kiel Waterworks · Kiel | 3,932 | - | - | 0 | None found |
| Cabelas - Richfield · Richfield | 3,931 | - | - | 0 | None found |
| Lancaster Waterworks · Lancaster | 3,907 | - | - | 0 | None found |
| Yorkville Utility Dist 1 · Union Grove | 3,900 | - | - | 0 | None found |
| Marshall Waterworks · Marshall | 3,862 | - | - | 0 | None found |
| Waupun Correctional Inst · Madison | 3,706 | - | - | 0 | None found |
| Horicon Waterworks · Horicon | 3,682 | - | - | 0 | None found |
| Bloomer Waterworks · Bloomer | 3,680 | - | - | 0 | None found |
| Omro Waterworks | 3,629 | - | - | 0 | None found |
| Combined Locks Waterworks · Combined Locks | 3,609 | - | - | 0 | None found |
| Black River Falls Waterworks · Black River Falls | 3,608 | - | - | 1 | Below limits |
| Seymour Waterworks · Seymour | 3,601 | - | - | 0 | None found |
| Waterloo Waterworks · Waterloo | 3,520 | - | - | 0 | None found |
| Sauk City Waterworks · Sauk City | 3,518 | - | - | 0 | None found |
| Stanley Waterworks · Stanley | 3,500 | - | - | 0 | None found |
| Barron Light & Water Dept · Barron | 3,423 | - | - | 0 | None found |
| Peshtigo Waterworks · Peshtigo | 3,420 | - | - | 0 | None found |
| Ellsworth Waterworks · Ellsworth | 3,304 | - | - | 1 | Below limits |
| Brillion Waterworks | 3,262 | - | - | 0 | None found |
| Tomahawk Waterworks · Tomahawk | 3,180 | 20.0 | - | 5 | Above limit |
| Denmark Waterworks | 2,684 | - | - | 0 | None found |
| Schofield Waterworks · Schofield | 2,205 | 4.3 | - | 6 | Above limit |
| Clinton Waterworks · Clinton | 2,119 | - | - | 0 | None found |
| Somers Water Utility · Somers | 1,930 | - | - | 0 | None found |
| Palmyra Waterworks · Palmyra | 1,756 | - | 5.2 | 2 | Above limit |
| New Berlin West Middle High School | 1,380 | - | - | 0 | None found |
| Shullsburg Waterworks · Shullsburg | 1,222 | - | - | 0 | None found |
| Hilbert Waterworks · Hilbert | 1,176 | - | - | 0 | None found |
| Arena Waterworks · Arena | 877 | - | - | 0 | None found |
| Bloomington Waterworks · Bloomington | 682 | - | - | 0 | None found |
| Birds Eye Foods · Darien | 610 | - | - | 0 | None found |
| Mt Zion Christian Church · Lake Geneva | 509 | - | - | 0 | None found |
| St Edward Sch & Ch · Appleton | 505 | - | - | 0 | None found |
| Forest Junction Pub Util · Forest Junction | 487 | - | - | 0 | None found |
| Schreiber Foods INC · West Bend | 260 | - | - | 0 | None found |
| Concor Tool & Machine INC · Hayward | 57 | 7.3 | 6.2 | 4 | Above limit |
| Eau Galle Cheese Factory · Durand | 50 | - | - | 0 | None found |
| Waterford on the Bay · Bayfield | 45 | - | - | 0 | None found |
| Mauston Green Acres · Colfax | 40 | - | - | 0 | None found |
On a private well in Wisconsin?
EPA's program only covers public systems. Private wells are never part of UCMR 5, so the only way to know is to test. Our well testing guide covers which lab tests to order, and the best well water systems covers what to install once you have results.
Cite this page
Well & Tap. "PFAS in Wisconsin drinking water: results for 202 systems." Data: U.S. EPA UCMR 5, final release August 2026. https://wellandtap.com/pfas/wisconsin/
Source: EPA UCMR 5 final occurrence data (August 2026); population from EPA SDWIS. Method.