Madison, WI

Madison tap water has 1 contaminant currently measured above EPA legal standards (Maximum Contaminant Levels), and 14 above independent health guidelines. 35 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.

Monitoring has detected 35 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, Fluoride, PFPeA (Perfluoropentanoic Acid), cis-1,2-Dichloroethylene, Trichlorofluoromethane, PFPeS (Perfluoropentane Sulfonate), PFHpA (Perfluoroheptanoic Acid), 6:2 FTS (Fluorotelomer Sulfonate), Chloromethane, Styrene, 1,1-Dichloroethane, Trichlorotrifluoroethane Freon, Benzene, 1,1-Dichloroethylene, Barium, Beryllium, Chromium (total), Nitrite, Metolachlor, PFBA (Perfluorobutanoic Acid). Additionally, 6 PFAS compounds have been detected at trace levels. 1 of these are above EPA legal limits. 14 exceed health guidelines. See individual system reports for concentrations relative to EPA limits.

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.

Yes. Madison water has a hardness of 320 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.

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).