State drinking water records
Wisconsin drinking water systems
1,050 community water systems serve Wisconsin and are listed below under 72 counties and on the pages of 629 cities and towns. Their own population figures add up to 4,263,550 people, a sum that counts people twice where one system sells water to another.
380 of them (36%) had at least one health-based violation in the last 10 years. 321 systems still have one unresolved.
989 rely mainly on groundwater and 61 on surface water, counting water bought from other systems.
1,048 systems filed a lead service line inventory listing 149,860 lead lines, 12,733 galvanized lines that must be replaced and 182,062 lines of unknown material.
148 systems are placed by mailing address or by the county their records name: EPA has no service area map for 127 of them, and 21 have one that does not line up with their own records.
- Community water systems
- 1,050
- People served, sum of each system's own figure
- 4,263,550
- Systems with a health-based violation, last 10 years
- 380
- Systems with one unresolved
- 321
- Lead service lines in inventories
- 149,860
Counties
72 countiesEach county counts the systems whose service area map reaches it. Systems placed only by a mailing address are listed on the county pages but not counted here.
| County | Systems | People served | With a health-based violation, 10 years | With one unresolved |
|---|---|---|---|---|
| Adams County | 9 | 5,901 | 2 | 0 |
| Ashland County | 8 | 12,217 | 3 | 1 |
| Barron County | 11 | 20,969 | 4 | 3 |
| Bayfield County | 7 | 6,393 | 3 | 3 |
| Brown County | 18 | 238,564 | 7 | 0 |
| Buffalo County | 7 | 4,819 | 3 | 2 |
| Burnett County | 6 | 4,735 | 1 | 2 |
| Calumet County | 10 | 21,602 | 6 | 1 |
| Chippewa County | 11 | 31,355 | 4 | 4 |
| Clark County | 13 | 14,251 | 6 | 4 |
| Columbia County | 25 | 38,130 | 13 | 8 |
| Crawford County | 8 | 8,796 | 3 | 1 |
| Dane County | 42 | 487,075 | 13 | 17 |
| Dodge County | 25 | 74,239 | 12 | 10 |
| Door County | 7 | 11,199 | 1 | 0 |
| Douglas County | 4 | 26,503 | 3 | 3 |
| Dunn County | 15 | 21,914 | 5 | 5 |
| Eau Claire County | 12 | 84,229 | 5 | 3 |
| Florence County | 2 | 1,280 | 1 | 1 |
| Fond du Lac County | 18 | 75,308 | 4 | 5 |
| Forest County | 7 | 6,205 | 4 | 4 |
| Grant County | 25 | 33,999 | 13 | 10 |
| Green County | 10 | 23,377 | 5 | 4 |
| Green Lake County | 6 | 9,207 | 2 | 0 |
| Iowa County | 15 | 13,529 | 8 | 9 |
| Iron County | 5 | 3,564 | 4 | 3 |
| Jackson County | 10 | 9,076 | 7 | 3 |
| Jefferson County | 21 | 61,558 | 9 | 6 |
| Juneau County | 15 | 12,352 | 3 | 7 |
| Kenosha County | 20 | 116,491 | 2 | 4 |
| Kewaunee County | 4 | 8,870 | 1 | 0 |
| La Crosse County | 18 | 91,739 | 6 | 6 |
| Lafayette County | 9 | 7,857 | 4 | 4 |
| Langlade County | 3 | 8,531 | 2 | 2 |
| Lincoln County | 5 | 13,376 | 3 | 1 |
| Manitowoc County | 14 | 57,255 | 6 | 3 |
| Marathon County | 21 | 92,468 | 11 | 13 |
| Marinette County | 9 | 19,061 | 3 | 1 |
| Marquette County | 5 | 1,515 | 2 | 1 |
| Menominee County | 3 | 5,190 | 0 | 0 |
| Milwaukee County | 17 | 944,370 | 1 | 4 |
| Monroe County | 11 | 33,190 | 4 | 2 |
| Oconto County | 10 | 11,105 | 4 | 1 |
| Oneida County | 6 | 11,611 | 4 | 3 |
| Outagamie County | 22 | 190,059 | 5 | 2 |
| Ozaukee County | 36 | 62,146 | 6 | 13 |
| Pepin County | 3 | 2,744 | 1 | 1 |
| Pierce County | 10 | 26,731 | 4 | 4 |
| Polk County | 13 | 15,964 | 4 | 5 |
| Portage County | 10 | 44,336 | 4 | 4 |
| Price County | 4 | 5,426 | 2 | 2 |
| Racine County | 12 | 151,115 | 6 | 8 |
| Richland County | 7 | 7,731 | 5 | 4 |
| Rock County | 16 | 125,173 | 9 | 4 |
| Rusk County | 7 | 4,838 | 5 | 2 |
| Sauk County | 23 | 43,496 | 10 | 7 |
| Sawyer County | 10 | 6,793 | 2 | 3 |
| Shawano County | 12 | 27,223 | 4 | 2 |
| Sheboygan County | 17 | 88,631 | 3 | 5 |
| St. Croix County | 16 | 60,701 | 5 | 6 |
| Taylor County | 5 | 6,348 | 3 | 2 |
| Trempealeau County | 14 | 16,825 | 5 | 5 |
| Vernon County | 13 | 12,693 | 8 | 6 |
| Vilas County | 10 | 5,998 | 3 | 2 |
| Walworth County | 26 | 69,760 | 8 | 4 |
| Washburn County | 6 | 4,899 | 2 | 3 |
| Washington County | 11 | 87,207 | 5 | 3 |
| Waukesha County | 49 | 246,162 | 18 | 16 |
| Waupaca County | 11 | 25,332 | 3 | 1 |
| Waushara County | 7 | 6,188 | 1 | 1 |
| Winnebago County | 10 | 144,798 | 3 | 3 |
| Wood County | 12 | 47,729 | 3 | 3 |
Largest systems
| System | Main county | People served | Main source | Health-based violations, 10 years | Unresolved | Lead lines |
|---|---|---|---|---|---|---|
| Milwaukee Waterworks | Milwaukee County | 626,000 | Surface water | 0 | 0 | 66,141 |
| Madison Water Utility | Dane County | 272,000 | Groundwater | 1 | 1 | 2 |
| Green Bay Waterworks | Brown County | 107,369 | Surface water | 0 | 0 | 4 |
| Racine Waterworks | Racine County | 105,100 | Surface water | 0 | 1 | 10,257 |
| Kenosha Water Utility | Kenosha County | 99,218 | Surface water | 0 | 0 | 1,677 |
| Appleton Waterworks | Outagamie County | 74,511 | Surface water | 0 | 0 | 4 |
| Waukesha Water Utility | Waukesha County | 70,718 | Purchased surface water | 149 | 2 | 0 |
| Eau Claire Waterworks | Eau Claire County | 70,587 | Groundwater | 0 | 0 | 100 |
| Janesville Water Utility | Rock County | 64,415 | Groundwater | 0 | 0 | 3 |
| West Allis Waterworks | Milwaukee County | 63,240 | Purchased surface water | 0 | 0 | 7,719 |
| Oshkosh Waterworks | Winnebago County | 63,000 | Surface water | 0 | 0 | 7,011 |
| La Crosse Waterworks | La Crosse County | 53,000 | Groundwater | 0 | 0 | 0 |
| Sheboygan Water Utilities | Sheboygan County | 49,931 | Surface water | 0 | 0 | 4,811 |
| Wauwatosa Waterworks | Milwaukee County | 49,064 | Purchased surface water | 0 | 0 | 8,707 |
| Fond Du Lac Waterworks | Fond du Lac County | 44,303 | Groundwater | 1 | 0 | 3,116 |
Systems with unresolved health-based violations
321 systemsThe 100 with the most unresolved violations are listed. The county pages list the other 221.
| System | Main county | People served | Main source | Health-based violations, 10 years | Unresolved | Lead lines |
|---|---|---|---|---|---|---|
| Manitou Falls Sanitary District No 1 | Douglas County | 95 | Groundwater | 9 | 19 | 0 |
| Williamsburg 207 209 and 214 | Ozaukee County | 70 | Groundwater | 3 | 12 | 0 |
| Pewaukee Village Waterworks | Waukesha County | 8,166 | Groundwater | 22 | 11 | 0 |
| Deer Trail Village | Marathon County | 120 | Groundwater | 1 | 11 | 0 |
| Andersons Trailer Court | Barron County | 95 | Groundwater | 2 | 9 | 0 |
| Willow Lane Estates | Rusk County | 34 | Groundwater | 0 | 9 | 0 |
| Edgewood Mobile Home Park | Vernon County | 90 | Groundwater | 1 | 7 | 0 |
| Mauston Green Acres | Juneau County | 40 | Groundwater | 0 | 7 | 0 |
| Sharon Waterworks | Walworth County | 1,549 | Groundwater | 1 | 6 | 12 |
| Lake Mills Waterworks | Jefferson County | 6,211 | Groundwater | 4 | 5 | 143 |
| Abbotsford Waterworks | Clark County and 1 other county | 2,502 | Groundwater | 2 | 5 | 0 |
| Fox Lake Correctional Institution | Dodge County | 1,850 | Groundwater | 1 | 5 | 0 |
| Browntown Waterworks | Green County | 256 | Groundwater | 2 | 5 | 0 |
| Poynette Mobile Estates | Columbia County | 150 | Groundwater | 5 | 5 | 0 |
| Glen Flora Waterworks | Rusk County | 93 | Groundwater | 4 | 5 | 0 |
| Woodland Park | Fond du Lac County | 66 | Groundwater | 0 | 5 | 0 |
| Pewaukee City Water and Sewer Utility | Waukesha County | 8,671 | Groundwater | 16 | 4 | 0 |
| Village of Lake Hallie Waterworks | Chippewa County | 6,701 | Groundwater | 1 | 4 | 0 |
| Village of Bloomfield | Walworth County | 4,071 | Groundwater | 3 | 4 | 0 |
| Shorewood Hills Waterworks | Dane County | 1,670 | Purchased groundwater | 0 | 4 | 0 |
| Maple Bluff Waterworks | Dane County | 1,342 | Purchased groundwater | 0 | 4 | 0 |
| Laona Sanitary Dist | Forest County | 950 | Groundwater | 2 | 4 | 0 |
| Stetsonville Waterworks | Taylor County | 563 | Groundwater | 4 | 4 | 0 |
| Kendall Waterworks | Monroe County | 458 | Groundwater | 3 | 4 | 5 |
| Wheatland Estates | Kenosha County | 450 | Groundwater | 0 | 4 | 0 |
| Tan Oak Apts | Kenosha County | 325 | Groundwater | 1 | 4 | 0 |
| Caravilla Education and Rehab Center | Rock County | 298 | Groundwater | 1 | 4 | 0 |
| Genoa Waterworks | Vernon County | 264 | Groundwater | 4 | 4 | 0 |
| Norris Inc | Waukesha County | 141 | Groundwater | 2 | 4 | 0 |
| Rimrock Road Neighborhood | Dane County | 135 | Purchased groundwater | 0 | 4 | 0 |
| Eagle Chateau Apts | Kenosha County | 125 | Groundwater | 0 | 4 | 0 |
| Carriage Hills Condominiums | Waukesha County | 50 | Groundwater | 2 | 4 | 0 |
| Village of Caledonia Water Utility - | Racine County | 21,819 | Purchased surface water | 1 | 3 | 0 |
| Sussex Village Hall & Water Utility | Waukesha County | 11,750 | Groundwater | 42 | 3 | 0 |
| Amery Waterworks | Polk County | 2,962 | Groundwater | 1 | 3 | 0 |
| Fontana Water Utility | Walworth County | 1,839 | Groundwater | 1 | 3 | 0 |
| Whitehall Waterworks | Trempealeau County | 1,820 | Groundwater | 1 | 3 | 0 |
| Montello Waterworks | Marquette County | 1,329 | Groundwater | 2 | 3 | 0 |
| Pepin Waterworks | Pepin County | 816 | Groundwater | 7 | 3 | 0 |
| Whitelaw Waterworks | Manitowoc County | 757 | Groundwater | 1 | 3 | 0 |
| Reeseville Waterworks | Dodge County | 718 | Groundwater | 2 | 3 | 38 |
| Montfort Waterworks | Grant County | 718 | Groundwater | 2 | 3 | 4 |
| Dallas Waterworks | Barron County | 365 | Groundwater | 1 | 3 | 0 |
| Radisson Waterworks | Sawyer County | 241 | Groundwater | 2 | 3 | 0 |
| Fulton Utility District | Rock County | 200 | Purchased groundwater | 1 | 3 | 0 |
| Bains Country Estates MHP | Sheboygan County | 200 | Groundwater | 1 | 3 | 0 |
| Pence Waterworks | Iron County | 191 | Purchased groundwater | 2 | 3 | 0 |
| Stitzer Sanitary Dist 1 | Grant County | 150 | Groundwater | 2 | 3 | 0 |
| Prairie Apts 1 & 2 | Kenosha County | 150 | Groundwater | 3 | 3 | 0 |
| Oak Park Community | Grant County | 90 | Groundwater | 2 | 3 | 0 |
| S and J Wild River MHP | Sawyer County | 90 | Groundwater | 1 | 3 | 0 |
| Silver Oak Apts | Kenosha County | 60 | Groundwater | 1 | 3 | 0 |
| Hilly Haven LLC | Price County | 45 | Groundwater | 1 | 3 | 0 |
| Birchwood Trailer Court | Rock County | 32 | Groundwater | 1 | 3 | 0 |
| Keyes Lake Mobile Home Park | Florence County | 30 | Groundwater | 4 | 3 | 0 |
| River Garden Apts | Ozaukee County | 25 | Groundwater | 1 | 3 | 0 |
| Prairie Lake Estates MHP | Barron County | 25 | Groundwater | 1 | 3 | 0 |
| Waukesha Water Utility | Waukesha County | 70,718 | Purchased surface water | 149 | 2 | 0 |
| Middleton Waterworks | Dane County | 23,868 | Groundwater | 1 | 2 | 0 |
| Glendale Waterworks | Milwaukee County | 12,883 | Purchased surface water | 0 | 2 | 11 |
| New Richmond Waterworks | St. Croix County | 10,824 | Groundwater | 1 | 2 | 0 |
| Holmen Waterworks | La Crosse County | 10,147 | Groundwater | 2 | 2 | 0 |
| Mukwonago Waterworks | Waukesha County | 8,190 | Groundwater | 0 | 2 | 0 |
| Muskego Water Utility | Waukesha County | 8,150 | Groundwater | 1 | 2 | 0 |
| Somerset Waterworks | St. Croix County | 3,334 | Groundwater | 1 | 2 | 0 |
| Johnson Creek Waterworks | Jefferson County | 3,318 | Groundwater | 1 | 2 | 6 |
| Ellsworth Waterworks | Pierce County | 3,304 | Groundwater | 1 | 2 | 0 |
| Tomahawk Waterworks | Lincoln County | 3,180 | Groundwater | 1 | 2 | 0 |
| Belleville Waterworks | Green County | 2,712 | Groundwater | 1 | 2 | 0 |
| Juneau Waterworks | Dodge County | 2,627 | Groundwater | 7 | 2 | 5 |
| Mineral Point Waterworks | Iowa County | 2,487 | Groundwater | 3 | 2 | 64 |
| Washburn Waterworks | Bayfield County | 2,280 | Groundwater | 2 | 2 | 0 |
| Darlington Waterworks | Lafayette County | 2,235 | Groundwater | 1 | 2 | 2 |
| Crandon Waterworks | Forest County | 1,958 | Groundwater | 1 | 2 | 0 |
| Spencer Waterworks | Marathon County | 1,848 | Groundwater | 1 | 2 | 0 |
| Wind Point Water Dept | Racine County | 1,804 | Purchased surface water | 0 | 2 | 0 |
| Cambridge Water & Sewer Utility | Dane County | 1,638 | Groundwater | 1 | 2 | 0 |
| Theresa Waterworks | Dodge County | 1,262 | Groundwater | 2 | 2 | 0 |
| Barneveld Waterworks | Iowa County | 1,258 | Groundwater | 3 | 2 | 1 |
| Amherst Waterworks | Portage County | 1,119 | Groundwater | 1 | 2 | 0 |
| Oakhill Correctional Inst | Dane County | 1,096 | Groundwater | 1 | 2 | 0 |
| Rio Waterworks | Columbia County | 1,095 | Groundwater | 1 | 2 | 0 |
| Montreal Waterworks | Iron County | 887 | Groundwater | 2 | 2 | 0 |
| Hale Park Meadows | Waukesha County | 720 | Groundwater | 0 | 2 | 0 |
| Saddle Ridge Estates | Columbia County | 700 | Groundwater | 1 | 2 | 0 |
| Eleva Waterworks | Trempealeau County | 635 | Groundwater | 2 | 2 | 0 |
| Brownsville Waterworks | Dodge County | 630 | Groundwater | 1 | 2 | 0 |
| Mequon Trail Townhomes | Ozaukee County | 615 | Groundwater | 1 | 2 | 0 |
| Suring Waterworks | Oconto County | 559 | Groundwater | 2 | 2 | 0 |
| Clark County Rehabilitation & Living Center | Clark County | 510 | Groundwater | 4 | 2 | 0 |
| Three Lakes Sanitary District | Oneida County | 500 | Groundwater | 2 | 2 | 0 |
| Alma Center Waterworks | Jackson County | 487 | Groundwater | 2 | 2 | 0 |
| Glenbeulah Waterworks | Sheboygan County | 461 | Groundwater | 1 | 2 | 0 |
| Cobb Waterworks | Iowa County | 458 | Groundwater | 1 | 2 | 0 |
| Birchwood Waterworks | Washburn County | 442 | Groundwater | 4 | 2 | 0 |
| Merrimac Waterworks | Sauk County | 440 | Groundwater | 2 | 2 | 0 |
| Hancock Waterworks | Waushara County | 419 | Groundwater | 2 | 2 | 0 |
| Lake Forest Water Coop | Dane County | 400 | Groundwater | 2 | 2 | 5 |
| Port Wing Sanitary District | Bayfield County | 400 | Groundwater | 0 | 2 | 0 |
| Cazenovia Waterworks | Richland County | 351 | Groundwater | 1 | 2 | 0 |
Counties come from the counties EPA lists each system serving, matched to 2024 Census counties; where EPA lists none, from the county coded in the system's ID, its service area map, or its mailing address. A county holding at least a fifth of a system's service area map is added when at least a fifth of that map lies in those counties. Towns are the ones EPA lists and the Census places such a map covers, always inside those counties. In New England, where EPA's town names a whole Town, it is not matched to the village of the same name. A system is not listed in a county holding less than a fifth of its map, or in a county or town its map reaches when the map lies mostly outside the counties EPA lists, so a page can leave out a system that serves part of the area. Methodology and limitations