Is Wauwatosa, WI Tap Water Safe? Quality & Contaminants

What was found in Wauwatosa's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

Contaminant	Level vs EPA limit	Suppliers	Source
Copper	164.5 µg/L 13% of the EPA limit 1300 µg/L Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2017	1/1	SYR4
TTHM	15.79 µg/L 20% of the EPA limit 80 µg/L Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Lead	11 µg/L 73% of the EPA limit 15 µg/L Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2017	1/1	SYR4
Chloroform	6.875 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Total Haloacetic Acids (HAA5)	6.03 µg/L 10% of the EPA limit 60 µg/L Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Bromodichloromethane	5.285 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Dichloroacetic Acid	3.52 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Dibromochloromethane	3.395 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Trichloroacetic Acid	1.73 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Monochloroacetic Acid	1.6 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Dibromoacetic Acid	0.8725 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Monobromoacetic Acid	0.5460 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Bromoform	0.5400 µg/L No EPA limit set Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2019	1/1	SYR4
Lead	0.0084 mg/L 56% of the EPA limit 0.0150 mg/L Main supplier: WAUWATOSA WATERWORKS · 49,064 people · 2023	1/1	LCR

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Wauwatosa

Supplier	Population served
WAUWATOSA WATERWORKS	49,064

Frequently asked questions about Wauwatosa tap water

Is Wauwatosa tap water safe to drink?

EPA testing detected 14 contaminants in the water serving Wauwatosa. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Wauwatosa?

1 public water supplier report drinking-water monitoring for Wauwatosa, Wisconsin to the EPA. Each is listed above with its population served.

What contaminants are in Wauwatosa's water?

The contaminants EPA monitoring detected in Wauwatosa include Copper, TTHM, Lead, Chloroform, Total Haloacetic Acids (HAA5). The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.