Wisconsin Water Quality
According to EPA Safe Drinking Water Information System (SDWIS), Wisconsin has 978 active community water systems in this extract. PlainEnviro's health-based slice lists 2,317 violation records across 50 systems with at least one such row. These are historical EPA registry counts, not a statewide drinkability score.
Health-based violation records for 978 community water systems in Wisconsin. Source: EPA Safe Drinking Water Information System (SDWIS).
Water Systems with Most Health-Based Records
| # | Water System | Health-Based Records | Health |
|---|---|---|---|
| 1 | WAUKESHA WATER UTILITY | 779 | Yes |
| 2 | SUSSEX VILLAGE HALL & WATER UTILITY | 106 | Yes |
| 3 | DELLS CLUB CONDO ASSOC 3 | 87 | Yes |
| 4 | PEWAUKEE VILLAGE WATERWORKS Pewaukee | 61 | Yes |
| 5 | PEWAUKEE CITY WATER AND SEWER UTILITY Pewaukee | 55 | Yes |
| 6 | WINNECONNE WATERWORKS Winneconne | 32 | Yes |
| 7 | ASHLAND WATER UTILITY Ashland | 31 | Yes |
| 8 | ELKHORN WATERWORKS Elkhorn | 26 | Yes |
| 9 | JEFFERSON WATERWORKS Jefferson | 23 | Yes |
| 10 | RANDOLPH WATER DEPT Randolph | 20 | Yes |
| 11 | WAUPUN CORRECTIONAL INST Madison | 18 | Yes |
| 12 | LA VALLE WATERWORKS | 18 | Yes |
| 13 | TOMAH WATERWORKS | 17 | Yes |
| 14 | DODGE SANITARY DIST 1 Dodge | 16 | Yes |
| 15 | BUTTERNUT WATERWORKS Butternut | 14 | Yes |
| 16 | MARSHVIEW TERRACE Stevens Point | 13 | Yes |
| 17 | MANITOU FALLS SANITARY DISTRICT NO 1 Superior | 13 | Yes |
| 18 | EVANSVILLE WATERWORKS | 12 | Yes |
| 19 | PEPIN WATERWORKS Pepin | 12 | Yes |
| 20 | JUNEAU WATERWORKS Juneau | 10 | Yes |
| 21 | TREMAIN MOBILE HOME PARK Stevens Point | 10 | Yes |
| 22 | CLARK COUNTY REHABILITATION & LIVING CENTER | 10 | Yes |
| 23 | HILLSBORO WATERWORKS | 10 | Yes |
| 24 | GENOA CITY WATERWORKS | 9 | Yes |
| 25 | POUND WATERWORKS Pound | 9 | Yes |
| 26 | SHELDON WATER UTILITY Sheldon | 9 | Yes |
| 27 | CRYSTAL LAKE RV RESORT LLC | 8 | Yes |
| 28 | LEROY SANITARY DISTRICT 1 Mayville | 8 | Yes |
| 29 | PARKVIEW APARTMENTS Milwaukee | 8 | Yes |
| 30 | LAKE MILLS WATERWORKS Lake Mills | 8 | Yes |
| 31 | BELOIT CITY OF | 8 | Yes |
| 32 | BLOOMFIELD, VILLAGE OF Pell Lake | 8 | Yes |
| 33 | ANTIGO WATERWORKS Antigo | 8 | Yes |
| 34 | HURLEY WATERWORKS Hurley | 8 | Yes |
| 35 | BROOKFIELD WATER UTILITY | 7 | Yes |
| 36 | SHADY OAKS MHP Spring Valley | 7 | Yes |
| 37 | TOWN OF FARMINGTON SANITARY DISTRICT Mindoro | 7 | Yes |
| 38 | PEARCES MOBILE HOME ESTATES Sparta | 7 | Yes |
| 39 | LAND O LAKES SANITARY DIST Land O Lakes | 7 | Yes |
| 40 | GLEN FLORA WATERWORKS Glen Flora | 7 | Yes |
| 41 | HIDDEN MEADOWS | 6 | Yes |
| 42 | STATELINE MOBILE HOME PARK Hazel Green | 6 | Yes |
| 43 | MONTFORT WATERWORKS Montfort | 6 | Yes |
| 44 | RIDGEWAY WATERWORKS Ridgeway | 6 | Yes |
| 45 | WATERLOO WATERWORKS Waterloo | 6 | Yes |
| 46 | SHARON WATERWORKS Sharon | 6 | Yes |
| 47 | NORTH FOND DU LAC WATERWORKS North Fond Du Lac | 6 | Yes |
| 48 | KELLNERSVILLE WATERWORKS Kellnersville | 6 | Yes |
| 49 | GOODMAN SANITARY DIST NO 1 | 6 | Yes |
| 50 | MOUNT STERLING WATERWORKS Mt Sterling | 6 | Yes |
Most Common Contaminants in Wisconsin
| Contaminant | Violations | Systems Affected |
|---|---|---|
| Combined Radium (-226 and -228) | 705 | 30 |
| Gross Alpha, Excl. Radon and U | 442 | 9 |
| LEAD AND COPPER RULE REVISIONS | 266 | 206 |
| Lead and Copper Rule | 239 | 114 |
| Groundwater Rule | 191 | 89 |
| Radium-228 | 135 | 2 |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | 134 | 71 |
| Revised Total Coliform Rule | 59 | 29 |
| TTHM | 33 | 8 |
| Nitrate | 30 | 16 |
| Arsenic | 21 | 4 |
| Benzene | 18 | 1 |
| Radium-226 | 11 | 2 |
| Coliform (TCR) | 9 | 6 |
| Total Haloacetic Acids (HAA5) | 9 | 3 |
Cities with Water Quality Issues
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About This Data
Water quality data is from the EPA Safe Drinking Water Information System (SDWIS). Health-based violations include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations. Only community water systems (CWS) in Wisconsin are included.
Source: U.S. Environmental Protection Agency, SDWIS Federal Reporting Services
Read our methodology - how this data is sourced, computed, and verified.