Water Quality Report
Madison, WI
Dane County · 278,417 residents · 8 water systems
38
Contaminants detected
6
PFAS compounds
287
Hardness (mg/L)
1
Above legal limits
15
Above health guidelines
Madison drinking water comes from groundwater wells. Based on the most recent monitoring data, 38 contaminants have been detected in the water supply, including Lead, Nitrate, Arsenic, Copper, and 34 others. PFAS compounds have been detected at trace levels in Madison water. Water hardness is 287 mg/L (very hard), which can cause scale buildup in appliances and reduce soap effectiveness.
Contaminants detected in Madison water
Detection does not necessarily mean unsafe levels. See individual reports for concentrations and EPA limits.
Lead0.0018 / 0.015 mg/L
12% of EPA limit
Nitrate2.7 / 10 mg/L
27% of EPA limit
Arsenic0.0067 / 0.01 mg/L
67% of EPA limit
Copper110 / 1300 ug/L
8% of EPA limit
Radon223 pCi/L
UnregulatedRadionuclide
Radium4.1 / 5 pCi/L
82% of EPA limit
Uranium0.66 / 30 ug/L
2% of EPA limit
Gross Alpha Radiation10.7 / 15 pCi/L
71% of EPA limit
Trichloroethylene0.26 / 5 ug/L
5% of EPA limit
Tetrachloroethylene1.3 / 5 ug/L
26% of EPA limit
Total Trihalomethanes3.6 / 80 ug/L
5% of EPA limit
Haloacetic Acids (HAA5)1.3 / 60 ug/L
2% of EPA limit
Atrazine0.044 / 3 ug/L
1% of EPA limit
Nickel0.0018 mg/L
UnregulatedInorganic
Selenium0.0012 / 0.05 mg/L
2% of EPA limit
Xylenes0.82 / 10000 ug/L
0% of EPA limit
PFPeA (Perfluoropentanoic Acid)3.6 ng/L
UnregulatedPFAS
6:2 FTS (Fluorotelomer Sulfonate)1.2 ng/L
UnregulatedPFAS
PFHpA (Perfluoroheptanoic Acid)1.5 ng/L
UnregulatedPFAS
Fluoride0.65 / 4 mg/L
16% of EPA limit
PFPeS (Perfluoropentane Sulfonate)0.71 ng/L
UnregulatedPFAS
Chloromethane0.45 ug/L
UnregulatedVOC
Trichlorofluoromethane0.41 ug/L
UnregulatedVOC
Styrene0.43 / 100 ug/L
0% of EPA limit
1,1-Dichloroethane0.11 ug/L
UnregulatedVOC
Trichlorotrifluoroethane Freon0.54 ug/L
Unregulated
Benzene0.39 / 5 ug/L
8% of EPA limit
1,1-Dichloroethylene0.18 / 7 ug/L
3% of EPA limit
cis-1,2-Dichloroethylene0.25 / 70 ug/L
0% of EPA limit
Ethylbenzene0.12 / 700 ug/L
0% of EPA limit
Metolachlor0.012 ug/L
UnregulatedVOC
Chromium (total)0.0016 / 0.1 mg/L
2% of EPA limit
Barium0.0133 / 2 mg/L
1% of EPA limit
Thallium0.00025 / 0.002 mg/L
13% of EPA limit
Beryllium0.0002 / 0.004 mg/L
5% of EPA limit
Nitrite0.0128 / 1 mg/L
1% of EPA limit
Turbidity0.15 NTU
Unregulated
PFBA (Perfluorobutanoic Acid)45 ng/L
UnregulatedPFAS
PFAS (6 compounds detected)
Microplastics (not routinely tested)
Water systems serving Madison
MADISON WATER UTILITY
272,000 servedGroundwater38 contaminants5 above guidelines
MENDOTA MENTAL HEALTH INST
2,787 servedGroundwater24 contaminants1 above legal limit2 above guidelines
SHOREWOOD HILLS WATERWORKS
1,670 servedGroundwater10 contaminants3 above guidelines
MAPLE BLUFF WATERWORKS
1,342 servedGroundwater6 contaminants2 above guidelines
LAKE FOREST WATER COOP
400 servedGroundwater7 contaminants1 above guideline
APPLEWOOD HILL
125 servedGroundwater7 contaminants1 above guideline
WOODBRIDGE ESTATES
48 servedGroundwater8 contaminants1 above guideline
PINE RIDGE APTS
45 servedGroundwater6 contaminants
Other cities in Dane County
Water quality reports for nearby Wisconsin communities.
Frequently asked questions
Is Madison, WI tap water safe to drink?
Madison tap water has 1 contaminant currently measured above EPA legal standards (Maximum Contaminant Levels), and 15 above independent health guidelines. 38 contaminants have been detected in the water supply, including Lead, Nitrate, Arsenic, Copper, Radon. View the detailed report for each water system to see specific levels, how they compare to both legal limits and health guidelines, and what actions to take.
What contaminants are in Madison water?
Monitoring has detected 38 contaminants in Madison's water supply: Lead, Nitrate, Arsenic, Copper, Radon, Radium, Uranium, Gross Alpha Radiation, Trichloroethylene, Tetrachloroethylene, Total Trihalomethanes, Haloacetic Acids (HAA5), Atrazine, Nickel, Selenium, Xylenes, PFPeA (Perfluoropentanoic Acid), 6:2 FTS (Fluorotelomer Sulfonate), PFHpA (Perfluoroheptanoic Acid), Fluoride, PFPeS (Perfluoropentane Sulfonate), Chloromethane, Trichlorofluoromethane, Styrene, 1,1-Dichloroethane, Trichlorotrifluoroethane Freon, Benzene, 1,1-Dichloroethylene, cis-1,2-Dichloroethylene, Ethylbenzene, Metolachlor, Chromium (total), Barium, Thallium, Beryllium, Nitrite, Turbidity, PFBA (Perfluorobutanoic Acid). Additionally, 6 PFAS compounds have been detected at trace levels. 1 of these are above EPA legal limits. 15 exceed health guidelines. See individual system reports for concentrations relative to EPA limits.
Does Madison water have PFAS?
Yes. 6 PFAS compounds have been detected in Madison's water supply at trace levels. PFAS are sometimes called "forever chemicals" because they do not break down in the environment. The EPA has set Maximum Contaminant Levels for several PFAS compounds. View the detailed report for specific concentrations.
Is Madison water hard?
Yes. Madison water has a hardness of 287 mg/L (very hard). Hard water is not a health concern but can cause scale buildup in water heaters and appliances, reduce soap effectiveness, and leave mineral deposits. Water softeners or conditioning systems can address hardness.
Where does Madison get its drinking water?
Madison's drinking water comes from groundwater wells that draw from underground aquifers. The water is treated and tested according to Wisconsin DNR and EPA requirements before distribution. Madison is served by 8 water systems, the largest being MADISON WATER UTILITY (serving 272,000 people).
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