Milwaukee County, Wisconsin: drinking water report. Milwaukee County encompasses the city of Milwaukee and surrounding communities including Wauwatosa,
Milwaukee County encompasses the city of Milwaukee and surrounding communities including Wauwatosa, West Allis, Cudahy, and Shorewood. The region draws drinking water primarily from Lake Michigan, with the Milwaukee Water Works operating one of the nation's oldest and largest municipal water systems. Several smaller municipalities run their own treatment facilities, while others purchase treated water from the city of Milwaukee.
Milwaukee's water supply has faced multiple challenges tied to its Lake Michigan source and aging distribution infrastructure. The city operates two treatment plants that draw water through intake pipes extending miles into the lake, treating an average of 100 million gallons daily. While the lake provides relatively clean raw water, the distribution system includes thousands of lead service lines that remain a significant concern for older neighborhoods.
Lead sampling data from Milwaukee County utilities has shown elevated readings in homes with lead service lines, particularly when water sits stagnant or during periods of temperature fluctuation. The Milwaukee Water Works has accelerated its lead service line replacement program after Wisconsin updated its regulations, but an estimated 70,000 lead lines still connect homes to water mains across the county. Properties built before 1951 face the highest risk, though homes constructed through the 1980s may still contain lead plumbing components.
PFAS contamination represents an emerging concern throughout Wisconsin, and Milwaukee County is no exception. The EPA's fifth Unregulated Contaminant Monitoring Rule detected PFAS compounds in water systems across the Great Lakes region. Milwaukee's lake-based supply shows lower PFAS levels than groundwater systems elsewhere in Wisconsin, but runoff from fire training facilities, industrial sites, and wastewater treatment plants continues to introduce these persistent chemicals into the watershed. The county's industrial history, particularly tanneries and metal finishing operations, left behind contamination that occasionally resurfaces during development or flooding events.
If your home was built before 1990, consider testing for lead, especially if you have young children or are pregnant. Flushing cold water for several minutes before first use and using cold water for drinking and cooking reduces lead exposure from pipes. Check your water to see current data for your specific address, review our water filter guide for certified filtration options, or access a detailed report on contaminants detected in your area. For broader context on Wisconsin's water challenges, visit the state page.
Drinking water is one exposure route. These federal datasets also cover Milwaukee County, WI.
The EPA places Milwaukee County, WI in Zone 2 - a moderate-risk category, with a predicted average indoor radon level between 2 and 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
80% of homes in Milwaukee County, WI were built before 1980, and 38% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Milwaukee County, WI averages 8.3 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide