Tap Water Quality Report
Tap water quality in GREEN BAY, Wisconsin
Tap water in GREEN BAY, Wisconsin receives a grade of F (56/100) from TapWaterSafety.org. It's served by GREEN BAY WATERWORKS. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Total PFOS and PFOA significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in GREEN BAY's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving GREEN BAY.
PFAS contamination
Severe concernPerfluorononanoic acid (PFNA), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 14.5 ppb, 241x above the EWG health guideline of 0.06 ppb.
Total PFOS and PFOA significantly above health guideline
Moderate concernTotal PFOS and PFOA detected at 1.26 ppt, 180x above the EWG health guideline of 0.007 ppt.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 23.7 ppb, 158x above the EWG health guideline of 0.15 ppb.
EPA compliance record
Official U.S. EPA records for GREEN BAY WATERWORKS (system ID WI4050356) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for GREEN BAY
Filters matched to the specific contaminants in GREEN BAY's water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in GREEN BAY's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
14.5 ppb | 0.06 | — | — | — | — | — | 241× over |
| Total PFOS and PFOA PFAS |
1.26 ppt | 0.007 | — | 100 | 100 | 0.007 | — | 180× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
23.7 ppb | 0.15 | 80.0 | 100 | — | — | — | 158× over |
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.155 ppt | 0.001 | 10.0 | — | — | — | — | 155× over |
| Bromodichloromethane Disinfection byproduct |
8.06 ppb | 0.06 | — | — | — | — | — | 134× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
6.85 ppb | 0.1 | 60.0 | 60 | — | — | — | 69× over |
| Dibromochloromethane Disinfection byproduct |
4.98 ppb | 0.1 | — | — | — | — | — | 50× over |
| Dibromoacetic acid Disinfection byproduct |
1.1 ppb | 0.03 | — | — | — | — | — | 37× over |
| Chloroform Disinfection byproduct |
9.6 ppb | 0.4 | — | — | — | — | — | 24× over |
| Bromate Disinfection byproduct |
2.08 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 21× over |
| Trichloroacetic acid Disinfection byproduct |
1.8 ppb | 0.1 | — | — | — | — | — | 18× over |
| Dichloroacetic acid Disinfection byproduct |
3.38 ppb | 0.2 | — | — | — | — | — | 17× over |
| Chromium (hexavalent) Heavy metal |
0.203 ppb | 0.02 | — | — | — | — | — | 10× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.515 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 5.7× over |
| Perfluorononanoic acid (PFNA) PFAS |
0.028 ppt | 0.006 | 10.0 | — | — | — | — | 4.7× over |
| Radium, combined (-226 and -228) Radiological |
0.18 pCi/L | 0.05 | 5.0 | — | — | — | — | 3.6× over |
| Bromoform Disinfection byproduct |
0.807 ppb | 0.5 | — | — | — | — | — | 1.6× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.454 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 1.5× over |
| Uranium Radiological |
0.24 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | Below guideline |
| Chlorate Disinfection byproduct |
68.6 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Nitrate Inorganic |
0.0448 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| Nitrate and nitrite Inorganic |
0.035 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| Atrazine Pesticide/Herbicide |
0.0083 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.0207 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Barium Heavy metal |
20.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.447 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
1.36 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Vanadium Other |
0.221 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
0.381 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.127 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.323 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.23 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.124 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.082 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Bromide Other |
32.7 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.683 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from GREEN BAY WATERWORKS.