Water Quality Report · Updated May 12, 2026
GREEN BAY WATERWORKS
GREEN BAY WATERWORKS delivers tap water graded F (50/100) by TapWaterSafety.org. The utility serves approximately 107,369 residents in GREEN BAY, Wisconsin using surface water. 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.
Is GREEN BAY tap water safe to drink?
GREEN BAY WATERWORKS delivers tap water that earns a grade of F (50/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 107,369 residents in GREEN BAY, drawing from surface water.
Public testing data identifies 18 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Total PFOS and PFOA, Total trihalomethanes (TTHMs), Perfluorohexane sulfonate (PFHXS), Bromodichloromethane, Haloacetic acids (HAA5), Dibromochloromethane, Dibromoacetic acid, Chloroform, Bromate, Trichloroacetic acid, Dichloroacetic acid, Chromium (hexavalent), Perfluorooctanoic acid (PFOA), Perfluorononanoic acid (PFNA), Radium, combined (-226 and -228), Bromoform, Perfluorooctane sulfonate (PFOS). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for GREEN BAY residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for GREEN BAY WATERWORKS.
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.
Contact GREEN BAY WATERWORKS
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for GREEN BAY
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 50/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
GREEN BAY WATERWORKS service area
This water system serves 1 community in Brown County, Wisconsin. Click any city for its dedicated tap water quality page.
Find the right filter for GREEN BAY water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.