Green Bay Waterworks
Green Bay, Wisconsin · PWSID: WI4050356
Green Bay Water Quality Summary
Green Bay Waterworks supplies drinking water to about 107,369 people in Green Bay, Wisconsin, and draws from surface water (rivers, lakes, or reservoirs), which requires fuller treatment for runoff, sediment, and microbial risk. On the IsWaterSafe scale it earns a good Water Safety Score of 80 out of 100 (Grade B), a composite of its EPA SDWIS violation and contaminant record.
EPA SDWIS shows no health-based or monitoring violations on record for Green Bay Waterworks, though 16 enforcement actions are logged in its history.
Across the single substance sampled, none exceeded its EPA limit. Combined Filter Effluent sits highest relative to its ceiling, detected at 0.5 NTU against an MCL of 1 NTU (sampled January 2016) — within the legal limit.
The most recent documented episode is a monitoring violation involving Combined Filter Effluent, beginning July 2016 and marked resolved November 2017.
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Detected Contaminants
| Contaminant | Detected Level | MCL (Limit) | Status | Sample Date |
|---|---|---|---|---|
| Combined Filter Effluent | 0.5 NTU | 1 NTU | Within Limit | Jan 1, 2016 |
Violation History
Frequently Asked Questions
Green Bay Waterworks has a Water Safety Score of B (80/100). The system serves 107,369 people and has 0 health violations on record. Check the contaminant table above for specific detected substances.
Green Bay Waterworks has 0 contaminant exceedances above EPA health guidelines. See the full contaminant detection table above for all tested substances and their levels relative to legal limits and health guidelines.
The Water Safety Score (0-100, grades A through F) is based on contaminant levels relative to legal limits, health guideline exceedances, violation history, and enforcement actions. Higher scores indicate fewer concerns.
If your water system has violations, request the Consumer Confidence Report from your utility, consider getting an independent water test from a certified lab, and look into certified water filters for specific contaminants of concern. For lead, run cold water for 30 seconds before drinking.
Water quality data sourced from EPA's Safe Drinking Water Information System (SDWIS). Safety scores are calculated based on contaminant levels, violations, and enforcement history. This is not a substitute for your utility's official Consumer Confidence Report.
Source: EPA Ground Water and Drinking Water, 2026.