Wisconsin water quality by county
71 counties with public water systems. Pick a county to see every system that serves it.
| County | Active systems | People served | Share with violations, 3 yr | Serious violators | Health flags |
|---|---|---|---|---|---|
| Adams County | 201 | 24,015 | 0 | 0 | |
| Ashland County | 84 | 12,567 | 1 | 1 | |
| Barron County | 194 | 29,581 | 0 | 1 | |
| Bayfield County | 194 | 10,732 | 0 | 0 | |
| Brown County | 148 | 246,754 | 0 | 0 | |
| Buffalo County | 69 | 8,759 | 0 | 0 | |
| Burnett County | 192 | 13,117 | 0 | 0 | |
| Calumet County | 51 | 24,368 | 0 | 0 | |
| Chippewa County | 217 | 51,557 | 0 | 1 | |
| Clark County | 97 | 14,410 | 1 | 0 | |
| Columbia County | 139 | 64,680 | 1 | 1 | |
| Crawford County | 49 | 12,710 | 0 | 0 | |
| Dane County | 298 | 528,025 | 1 | 0 | |
| Dodge County | 178 | 73,270 | 2 | 1 | |
| Door County | 450 | 34,647 | 0 | 1 | |
| Douglas County | 188 | 34,606 | 1 | 1 | |
| Dunn County | 87 | 26,212 | 0 | 1 | |
| Eau Claire County | 111 | 92,606 | 0 | 1 | |
| Florence County | 45 | 2,791 | 1 | 1 | |
| Fond du Lac County | 209 | 87,182 | 0 | 0 | |
| Forest County | 57 | 8,042 | 0 | 1 | |
| Grant County | 90 | 41,678 | 0 | 0 | |
| Green County | 52 | 28,087 | 0 | 0 | |
| Green Lake County | 70 | 14,772 | 0 | 0 | |
| Iowa County | 77 | 25,880 | 1 | 0 | |
| Iron County | 59 | 5,795 | 0 | 0 | |
| Jackson County | 106 | 19,930 | 0 | 0 | |
| Jefferson County | 194 | 88,318 | 0 | 0 | |
| Juneau County | 146 | 26,525 | 0 | 1 | |
| Kenosha County | 227 | 137,235 | 2 | 3 | |
| Kewaunee County | 72 | 12,146 | 0 | 0 | |
| La Crosse County | 122 | 98,888 | 0 | 1 | |
| Lafayette County | 40 | 11,166 | 0 | 1 | |
| Langlade County | 117 | 19,356 | 0 | 1 | |
| Lincoln County | 97 | 19,035 | 0 | 1 | |
| Manitowoc County | 140 | 66,107 | 0 | 0 | |
| Marathon County | 195 | 103,492 | 0 | 0 | |
| Marinette County | 191 | 26,847 | 1 | 0 | |
| Marquette County | 154 | 17,209 | 0 | 0 | |
| Milwaukee County | 85 | 952,731 | 0 | 0 | |
| Monroe County | 103 | 39,323 | 0 | 1 | |
| Oconto County | 203 | 20,347 | 1 | 1 | |
| Oneida County | 347 | 40,673 | 0 | 1 | |
| Outagamie County | 107 | 179,613 | 0 | 0 | |
| Ozaukee County | 250 | 92,356 | 1 | 2 | |
| Pepin County | 22 | 4,102 | 0 | 1 | |
| Pierce County | 94 | 32,388 | 0 | 1 | |
| Polk County | 189 | 22,901 | 0 | 1 | |
| Portage County | 149 | 50,398 | 1 | 2 | |
| Price County | 74 | 8,178 | 0 | 1 | |
| Racine County | 194 | 180,642 | 3 | 5 | |
| Richland County | 37 | 10,808 | 0 | 0 | |
| Rock County | 158 | 148,807 | 0 | 0 | |
| Rusk County | 85 | 7,635 | 1 | 1 | |
| Sauk County | 194 | 67,764 | 0 | 2 | |
| Sawyer County | 193 | 13,479 | 0 | 0 | |
| Shawano County | 117 | 24,442 | 0 | 0 | |
| Sheboygan County | 216 | 120,227 | 0 | 0 | |
| St. Croix County | 165 | 57,543 | 0 | 1 | |
| Taylor County | 60 | 11,994 | 0 | 0 | |
| Trempealeau County | 77 | 20,296 | 0 | 0 | |
| Vernon County | 67 | 16,834 | 0 | 1 | |
| Vilas County | 454 | 41,832 | 0 | 0 | |
| Walworth County | 251 | 95,627 | 2 | 1 | |
| Washburn County | 132 | 9,670 | 0 | 0 | |
| Washington County | 267 | 133,806 | 0 | 2 | |
| Waukesha County | 589 | 323,615 | 2 | 3 | |
| Waupaca County | 207 | 36,050 | 0 | 0 | |
| Waushara County | 197 | 14,504 | 0 | 1 | |
| Winnebago County | 146 | 147,317 | 0 | 0 | |
| Wood County | 149 | 58,559 | 0 | 2 |
under 30% 30 to 59% 60% and over
About this data
Share with violations counts any violation in the past three years, including monitoring and reporting lapses. Counts cover active systems; systems serving more than one county are counted in each.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Wisconsin records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.