What was found in Green Bay's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Fluoride | 1765 µg/L 44% of the EPA limit 4000 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019 | 2/5 | SYR4 |
| Nitrate | 1162.5 µg/L 12% of the EPA limit 10000 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019 | 2/5 | SYR4 |
| Copper | 790 µg/L 61% of the EPA limit 1300 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019 | 5/5 | SYR4 |
| Nitrate-Nitrite | 309 µg/L 3.1% of the EPA limit 10000 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2014
Highest in the city: 348 µg/L — HOWARD WATERWORKS · 21,133 people · 2017 | 2/5 | SYR4 |
| Barium | 46.35 µg/L 2.3% of the EPA limit 2000 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2017
Highest in the city: 168 µg/L — HOWARD WATERWORKS · 21,133 people · 2017 | 2/5 | SYR4 |
| TTHM | 39.663 µg/L 50% of the EPA limit 80 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 67.9025 µg/L — ALLOUEZ WATERWORKS · 13,923 people · 2019 | 5/5 | SYR4 |
| Chloroform | 19.55 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 45.1 µg/L — ALLOUEZ WATERWORKS · 13,923 people · 2019 | 5/5 | SYR4 |
| Total Haloacetic Acids (HAA5) | 9.965 µg/L 17% of the EPA limit 60 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 33.996 µg/L — BELLEVUE WATERWORKS · 16,715 people · 2019 | 5/5 | SYR4 |
| Gross Alpha, Excl. Radon And U | 27.745 pCi/L 185% of the EPA limit, at the 95th percentile of samples — 15 pCi/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2014 | 2/5 | SYR4 |
| Lead | 22 µg/L 147% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019 | 5/5 | SYR4 |
| Arsenic | 18 µg/L 180% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2017 | 2/5 | SYR4 |
| Bromodichloromethane | 12.55 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 18 µg/L — ALLOUEZ WATERWORKS · 13,923 people · 2019 | 5/5 | SYR4 |
| Trichloroacetic Acid | 3.6 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 17 µg/L — BELLEVUE WATERWORKS · 16,715 people · 2019 | 5/5 | SYR4 |
| Dichloroacetic Acid | 5.24 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 16 µg/L — HOWARD WATERWORKS · 21,133 people · 2019 | 5/5 | SYR4 |
| Combined Radium (-226 And -228) | 9.0025 pCi/L 180% of the EPA limit, at the 95th percentile of samples — 5 pCi/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2014 | 2/5 | SYR4 |
| Dibromochloromethane | 6.7 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 8.05 µg/L — ASHWAUBENON WATERWORKS · 17,730 people · 2019 | 5/5 | SYR4 |
| Bromate | 5.615 µg/L 56% of the EPA limit 10 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019 | 1/5 | SYR4 |
| Combined Uranium | 4.8 µg/L 16% of the EPA limit 30 µg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2014 | 2/5 | SYR4 |
| Monochloroacetic Acid | 2.98 µg/L No EPA limit set Highest in the city: BELLEVUE WATERWORKS · 16,715 people · 2019 | 3/5 | SYR4 |
| P-Dichlorobenzene | 2.15 µg/L 2.9% of the EPA limit 75 µg/L Highest in the city: HOWARD WATERWORKS · 21,133 people · 2019 | 1/5 | SYR4 |
| Dibromoacetic Acid | 1.4 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 1.895 µg/L — BELLEVUE WATERWORKS · 16,715 people · 2019 | 5/5 | SYR4 |
| Monobromoacetic Acid | 0.8300 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019
Highest in the city: 1.47 µg/L — BELLEVUE WATERWORKS · 16,715 people · 2019 | 5/5 | SYR4 |
| Bromoform | 1.2 µg/L No EPA limit set Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2019 | 3/5 | SYR4 |
| Thallium, Total | 0.5500 µg/L 28% of the EPA limit 2 µg/L Highest in the city: HOWARD WATERWORKS · 21,133 people · 2019 | 1/5 | SYR4 |
| Lead | 0.0025 mg/L 17% of the EPA limit 0.0150 mg/L Main supplier: GREEN BAY WATERWORKS · 107,369 people · 2023
Highest in the city: 0.0059 mg/L — ALLOUEZ WATERWORKS · 13,923 people · 2023 | 5/5 | LCR |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Green Bay
| Supplier | Population served |
|---|---|
| GREEN BAY WATERWORKS | 107,369 |
| HOWARD WATERWORKS | 21,133 |
| ASHWAUBENON WATERWORKS | 17,730 |
| BELLEVUE WATERWORKS | 16,715 |
| ALLOUEZ WATERWORKS | 13,923 |
Frequently asked questions about Green Bay tap water
Is Green Bay tap water safe to drink?
EPA testing detected 25 contaminants in the water serving Green Bay. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Green Bay?
5 public water suppliers report drinking-water monitoring for Green Bay, Wisconsin to the EPA. Each is listed above with its population served.
What contaminants are in Green Bay's water?
The contaminants EPA monitoring detected in Green Bay include Fluoride, Nitrate, Copper, Nitrate-Nitrite, Barium. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.