Public Water Systems
10,988 active public water systems in WI, tracked from EPA's Safe Drinking Water Information System (SDWIS) across all 50 states. See our methodology.
| System Name | Location | Population | Violations | PFAS |
| Curtiss Waterworks | Curtiss, WI | 346 | 105 | - |
| Friesland Waterworks | Friesland, WI | 345 | 127 | - |
| Norway Ev Lutheran Church and Mustard Seed Preschool | Wind Lake, WI | 345 | 19 | - |
| Winter Waterworks | Winter, WI | 344 | 47 | - |
| Berkots | Twin Lakes, WI | 340 | 132 | - |
| St Johns Northwestern Academies | Delafield, WI | 340 | 222 | - |
| Rosholt Elem School | Rosholt, WI | 338 | 15 | - |
| Lowell Waterworks | Lowell, WI | 337 | 25 | - |
| Lakewood Supervalu | Onalaska, WI | 335 | 0 | - |
| Hawkins Waterworks | Kennan, WI | 333 | 56 | - |
| Fairbanks Morse Engine Div | Beloit, WI | 330 | 19 | - |
| Shoreland Lutheran High School | Kenosha, WI | 330 | 24 | - |
| Cedar Lake Home 5 | West Bend, WI | 330 | 118 | - |
| Church of the Resurrection | Pewaukee, WI | 330 | 12 | - |
| Lannoye Elementary School | Pulaski, WI | 330 | 10 | - |
| Hwy 51 Truckstop Site 4488 | Rothschild, WI | 328 | 65 | - |
| Tan Oak Apts | Brookfield, WI | 325 | 603 | - |
| The Chapel Whitewater | Whitewater, WI | 325 | 0 | - |
| Weasler Engineering | West Bend, WI | 325 | 188 | - |
| University Lake Lower School | Hartland, WI | 325 | 9 | - |
| Scouting America Camp Long Lake 2 South Shower House | Waukesha, WI | 325 | 0 | - |
| Trinity Lutheran Ch | Sheboygan, WI | 323 | 20 | - |
| Silo Ridge Clubhouse | Fort Atkinson, WI | 322 | 0 | - |
| Rosendale Mart | Waterford, WI | 322 | 0 | - |
| Herzl Camp Hak 1 West Bathroom | Webster, WI | 322 | 0 | - |
| Herzl Camp Hak 2 East Bathroom | Webster, WI | 322 | 0 | - |
| Richland Center Intermediate School | Richland Center, WI | 321 | 17 | - |
| Fourwinds Market Gas Station | Siren, WI | 321 | 0 | - |
| Fourwinds Market Grocery Store | Siren, WI | 321 | 0 | - |
| Silver Springs Campsites Hilltop Well | Rio, WI | 320 | 1 | - |
| Silver Springs Campsites Office and Pool | Rio, WI | 320 | 1 | - |
| Leroy Sanitary District 1 | Mayville, WI | 320 | 131 | - |
| Olins Juda Oasis | Granger, WI | 320 | 77 | - |
| Tower Junction | Platteville, WI | 320 | 11 | - |
| Milwaukee Country Club Clubhouse | Milwaukee, WI | 320 | 22 | - |
| Country Mart | Richfield, WI | 320 | 5 | - |
| Road America Turn 1 Well | Elkhart Lake, WI | 320 | 0 | - |
| Recreacres Mhc LLC | West Covina, WI | 320 | 200 | - |
| Rivermoor Golf Club | Waterford, WI | 319 | 2 | - |
| Merrill Hills Country Club | Waukesha, WI | 319 | 2 | - |
| Wheeler Waterworks Assoc | Wheeler, WI | 317 | 288 | - |
| Oakdale Waterworks | Oakdale, WI | 317 | 11 | - |
| Cimarolis Supper Club | Portage, WI | 316 | 11 | - |
| Lincoln Hills School | Irma, WI | 316 | 50 | - |
| Viking Village Campground & Resort - North | Stoughton, WI | 315 | 0 | - |
| House on the Rock Winter Well | Spring Green, WI | 315 | 0 | - |
| Hb Performance Systems Inc | Mequon, WI | 315 | 16 | - |
| Lakeside Elementary School | Oshkosh, WI | 315 | 24 | - |
| Northernaire Sanitary District | Three Lakes, WI | 315 | 56 | - |
| Wilderness Crossing Travel Cntr | Rothschild, WI | 313 | 30 | - |