Water Quality: Delafield, WI
11 water systems • 1,613 people served
Multiple Health ViolationsWater Quality Summary
Delafield is served by 11 public water systems with a combined service population of 1,613 people, and has 85 EPA Safe Drinking Water Act violations on record. Critically, 9 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Delafield's violation count is 160% above the national average for Wisconsin. Contaminants associated with violations include Chlorine, E. coli, Stage 2 DBP.
Contaminants Found
Eye and nose irritation at high levels; long-term exposure above the MCL may cause liver and kidney damage.
Common source: Water treatment disinfectant added to kill harmful microorganisms
EPA limit: 4.0 mg/L (MRDL — Maximum Residual Disinfectant Level)
Causes gastrointestinal illness; certain strains (e.g., O157:H7) can cause severe kidney failure and death.
Common source: Fecal contamination from humans or animals entering the water supply
EPA limit: Zero (no E. coli permitted in drinking water)
Trihalomethanes and haloacetic acids that increase cancer risk and may cause adverse reproductive outcomes.
Common source: Chlorine disinfection reacting with natural organic matter in source water
EPA limit: TTHM: 0.080 mg/L; HAA5: 0.060 mg/L
Water Systems Serving Delafield
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| NASHOTAH HOUSE | WI2682512 | Groundwater | 350 | 3 |
| ST JOHNS NORTHWESTERN ACADEMIES | WI2680761 | Groundwater | 340 | 32 |
| DELAFIELD WATERWORKS | WI2684642 | Groundwater | 300 | 2 |
| ARBORS | WI2682795 | Groundwater | 280 | 12 |
| COUNTRY AIRE APARTMENTS 2 | WI2680247 | Groundwater | 90 | 1 |
| COUNTRY AIRE APARTMENTS 3 | WI2680249 | Groundwater | 80 | 1 |
| RIVER VALLEY APTS NORTH | WI1281099 | Groundwater | 48 | 6 |
| RIVER VALLEY APTS SOUTH | WI1281100 | Groundwater | 48 | 9 |
| SANCTUARY OF DELAFIELD | WI2685951 | Groundwater | 27 | 8 |
| WELLS ST STATION 425 WEST | WI2686466 | Groundwater | 25 | 6 |
| WELLS ST STATION 435 EAST | WI2686619 | Groundwater | 25 | 5 |
Concerned About Your Water?
A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.
Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.
Other Cities in Wisconsin
Data Sources
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.