Green Bay Tap Water Quality: Is It Safe to Drink? (2026 Report)

Green Bay, Wisconsin tap water receives a grade of D (24/100), which is considered poor. 1 contaminant(s) exceed EPA maximum contaminant levels and 107 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

Of the 77 contaminants tested in Green Bay's water supply, the most notable include Copper (90th percentile), Lead (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.

Yes, Green Bay has 107 EPA violation(s) on record, with the most recent in 2024. Violation types include TT, Other, MON. 57 of these are health-based violations, which are the most serious category.

Based on EPA data, using a water filter in Green Bay is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.

Green Bay's drinking water is sourced from surface water and supplied by GREEN BAY WATERWORKS and 3 other water system(s). The system serves approximately 159,373 people. Surface water sources include rivers, lakes, and reservoirs.

Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Green Bay's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.

Green Bay's water quality score of 24/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our Wisconsin state page to see how all cities in the state compare.

If you have concerns about Green Bay's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (GREEN BAY WATERWORKS) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.