Water Quality Report · Updated May 12, 2026
Madison Department of Public Works
Madison Department of Public Works delivers tap water graded D (60/100) by TapWaterSafety.org. The utility serves approximately 259,000 residents in Madison, Wisconsin using groundwater from the Madison aquifer wells. The most significant water quality concerns are: Lead detected in source water; Arsenic significantly above health guideline; Chromium-6 detected; Radium-228 detected. For questions, the utility can be reached at (414) 403-6648.
Is Madison tap water safe to drink?
Madison Department of Public Works delivers tap water that earns a grade of D (60/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including lead detected in source water.
The utility serves 259,000 residents in Madison, drawing from groundwater (Madison aquifer wells) and disinfecting with free chlorine.
Public testing data identifies 21 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Arsenic, Arsenic, Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Haloacetic Acids (HAA5), Chromium-6 (Hexavalent), Chromium-6 (Hexavalent), Chromium-6 (Hexavalent), Total Trihalomethanes (TTHMs), Total Trihalomethanes (TTHMs), Nitrate, Nitrate, Total Trihalomethanes (TTHMs), Nitrate, Radium-228, Radium-228, Radium-228, Lead, Lead, Lead. 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.
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for Madison Department of Public Works.
Lead detected in source water
Severe concernLead detected at 1.1 ppb. EWG considers no level of lead safe; EPA's action level is 15 ppb.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 0.648 ppb, 162x above the EWG health guideline of 0.004 ppb.
Chromium-6 detected
Moderate concernChromium-6 detected at 0.44 ppb.
Radium-228 detected
Moderate concernRadium-228 detected at 0.06 pCi/L.
Contact Madison Department of Public Works
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Water Quality Contact
For questions about contaminants, test results, or your Consumer Confidence Report.
Treatment Plant
Recommended water filters for Madison
Filters matched to the specific contaminants in this water supply.
NSF/ANSI 53 certified for lead removal
$80-$750NSF 53 is the gold standard certification for lead removal. Required when lead is a documented concern.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Reverse Osmosis or water softener
$249-$750RO removes radium effectively; ion-exchange water softeners also reduce radium concentration.
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 60/100 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 |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
0.648 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2023 | 162× over |
| Arsenic Heavy metal |
0.6 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2024 | 150× over |
| Arsenic Heavy metal |
0.431 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 2022 | 108× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
5.87 ppb | 0.1 | 60 | 60 | — | — | 2023 | 59× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
4.99 ppb | 0.1 | 60 | 60 | — | — | 2022 | 50× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
4.8 ppb | 0.1 | 60 | 60 | — | — | 2024 | 48× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.44 ppb | 0.02 | — | — | — | 0.02 | 2024 | 22× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.419 ppb | 0.02 | — | — | — | 0.02 | 2023 | 21× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.398 ppb | 0.02 | — | — | — | 0.02 | 2022 | 20× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
5.2 ppb | 0.6 | 80 | 100 | — | — | 2024 | 8.7× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
4.7 ppb | 0.6 | 80 | 100 | — | — | 2023 | 7.8× over |
| Nitrate Inorganic |
1.02 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2022 | 7.3× over |
| Nitrate Inorganic |
0.9 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 6.4× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
3.66 ppb | 0.6 | 80 | 100 | — | — | 2022 | 6.1× over |
| Nitrate Inorganic |
0.83 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2023 | 5.9× over |
| Radium-228 Radiological |
0.069 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2023 | 3.6× over |
| Radium-228 Radiological |
0.06 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2024 | 3.2× over |
| Radium-228 Radiological |
0.05 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2022 | 2.6× over |
| Lead Heavy metal |
1.1 ppb | 0 | 15 | 5 | 10 | 0.2 | 2024 | — |
| Lead Heavy metal |
1.03 ppb | 0 | 15 | 5 | 10 | 0.2 | 2023 | — |
| Lead Heavy metal |
0.86 ppb | 0 | 15 | 5 | 10 | 0.2 | 2022 | — |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
5.2 ppb | 0.6 | 80 | 100 | — | — | 8.7× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
4.8 ppb | 0.1 | 60 | 60 | — | — | 48× over |
| Lead Heavy metal |
1.1 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Arsenic Heavy metal |
0.6 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 150× over |
| Radium-228 Radiological |
0.06 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 3.2× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.44 ppb | 0.02 | — | — | — | 0.02 | 22× over |
| Nitrate Inorganic |
0.9 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 6.4× over |
| Contaminant | Detected (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
4.7 ppb | 0.6 | 80 | 100 | — | — | 7.8× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
5.87 ppb | 0.1 | 60 | 60 | — | — | 59× over |
| Lead Heavy metal |
1.03 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Arsenic Heavy metal |
0.648 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 162× over |
| Radium-228 Radiological |
0.069 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 3.6× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.419 ppb | 0.02 | — | — | — | 0.02 | 21× over |
| Nitrate Inorganic |
0.83 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 5.9× over |
| Contaminant | Detected (2022) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
3.66 ppb | 0.6 | 80 | 100 | — | — | 6.1× over |
| Haloacetic Acids (HAA5) Disinfection byproduct |
4.99 ppb | 0.1 | 60 | 60 | — | — | 50× over |
| Lead Heavy metal |
0.86 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
| Arsenic Heavy metal |
0.431 ppb | 0.004 | 10 | 10 | 10 | 0.004 | 108× over |
| Radium-228 Radiological |
0.05 pCi/L | 0.019 | 5 | — | 0.1 | 0.019 | 2.6× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.398 ppb | 0.02 | — | — | — | 0.02 | 20× over |
| Nitrate Inorganic |
1.02 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 7.3× over |
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, and Madison Department of Public Works's Consumer Confidence Report.
Madison Department of Public Works service area
This water system serves 1 community in Dane County, Wisconsin. Click any city for its dedicated tap water quality page.
Find the right filter for Madison water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.