Is Milwaukee, WI Tap Water Safe to Drink?

Where Does Milwaukee Get Its Water?

Milwaukee's drinking water comes from Lake Michigan, one of the largest freshwater sources in the world. The primary provider is Milwaukee Waterworks, which serves the city directly. Several surrounding communities, including Brown Deer, Glendale, Shorewood, Wauwatosa, West Allis, and Whitefish Bay, operate their own water systems that draw from Milwaukee's supply or the same lake source.

The Linnwood Water Treatment Plant is a major recognizable facility in Milwaukee's treatment network, referenced in the distribution data as a key point of entry for the regional system. Water processed there reaches homes across multiple communities in the metro area.

The surrounding utilities, including Wauwatosa Water Utility and others, connect to Milwaukee's system through intertie points, meaning treated water from the same core sources reaches most of the 32 ZIP codes covered in this data.

How Is Milwaukee Tap Water Treated?

Milwaukee Waterworks uses a multi-step treatment process. Water goes through coagulation to clump fine particles together, followed by filtration to remove them. Biological treatment is also part of the process, which uses natural microbial activity to break down certain organic compounds before disinfection.

Disinfection uses a combination of ozone and chlorine-based methods, including free chlorine applied at various stages. Ozone is a powerful oxidant that helps neutralize organic matter and some chemical contaminants before the water reaches the distribution system. Residual chlorine keeps the water protected as it travels through pipes to your tap.

Ultraviolet light treatment is also part of the process, adding another barrier against microbial contamination. This layered approach, combining biological treatment, ozone, UV, and chlorine, is among the more thorough treatment trains used by large US utilities.

What's in Milwaukee Tap Water?

The most widely detected substances in recent EPA testing are PFAS compounds, a group of synthetic chemicals, found across all 32 tested ZIP codes. Four PFAS types were identified: PFTrDA, 8:2 FTS, 6:2 FTS, and PFBA, each detected at or near 0.005 micrograms per liter. None exceeded their respective EPA guidelines. Lithium was also detected across all ZIP codes at up to 9 micrograms per liter, which is at the reporting threshold.

6:2 FTS had a documented EPA drinking water standard of 0.005 micrograms per liter, and Milwaukee's measured maximum matched that level exactly without going above it. The other PFAS compounds and lithium were similarly at or below their respective benchmarks. No contaminant in this dataset exceeded an enforceable federal limit.

PFAS compounds are widely used in industrial and consumer products and can enter drinking water sources through manufacturing discharge or runoff. Their detection in Lake Michigan-sourced water is consistent with broader Great Lakes region patterns. Lithium occurs naturally in some source waters and is also present in certain industrial discharges; there is no federal enforceable maximum contaminant level for lithium in drinking water.

Health Risk Profile for Milwaukee

The PFAS compounds detected in Milwaukee's water are at or near their screening benchmarks but do not exceed enforceable federal limits. The EPA has set enforceable maximum contaminant levels for some PFAS compounds, including PFOA and PFPF, but the specific types found here (PFTrDA, 8:2 FTS, 6:2 FTS, PFBA) are regulated under different or non-enforceable benchmarks depending on the compound. All measured values fell within acceptable ranges.

Lithium in Milwaukee's water reached 9 micrograms per liter, which equals the reporting threshold used in EPA testing. There is no federal enforceable drinking water limit for lithium; the 9 micrograms per liter figure represents a non-regulatory screening benchmark, not a legal violation. Sensitive groups, including infants, pregnant individuals, and people with kidney conditions, may want to consult a doctor about long-term lithium exposure at any level, as research on health effects at low concentrations is still developing.

If you want additional protection against PFAS, look for a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI P473. NSF/ANSI is an independent third-party certification that confirms a filter actually removes what it claims to. For chlorine taste or odor, NSF/ANSI 42 covers carbon-based filters. These certifications appear on the product packaging or the manufacturer's website.

For most healthy adults, Milwaukee's tap water poses low risk based on current measurements. The science on some PFAS compounds at low concentrations is still evolving, and EPA continues to update its guidance. Staying informed through Milwaukee Waterworks' annual water quality report is the best way to track any changes.