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Tap water quality report

West Allis, WI

EPA monitoring detected 13 contaminants across the 1 water supplier serving West Allis. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
63,240
people served
13
contaminants found
Wisconsin rankings Lead in Wisconsin PFAS in Wisconsin

What was found in West Allis'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.

ContaminantLevel vs EPA limitSuppliersSource
Copper
87.2 µg/L 6.7%
of the EPA limit 1300 µg/L
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2017
1/1 SYR4
TTHM
15.4225 µg/L 19%
of the EPA limit 80 µg/L
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Lead
7.385 µg/L 49%
of the EPA limit 15 µg/L
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2017
1/1 SYR4
Chloroform
6.4 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Bromodichloromethane
5.4 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Total Haloacetic Acids (HAA5)
5.394 µg/L 9%
of the EPA limit 60 µg/L
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Dichloroacetic Acid
3.3 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Dibromochloromethane
3.21 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Trichloroacetic Acid
1.56 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Dibromoacetic Acid
0.8100 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Monobromoacetic Acid
0.6860 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Bromoform
0.6460 µg/L
No EPA limit set
Main supplier: WEST ALLIS WATERWORKS · 63,240 people · 2019
1/1 SYR4
Lead
0.0024 mg/L 16%
of the EPA limit 0.0150 mg/L
Main supplier: WEST ALLIS WATERWORKS · 63,240 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 West Allis

SupplierPopulation served
WEST ALLIS WATERWORKS 63,240

Frequently asked questions about West Allis tap water

Is West Allis tap water safe to drink?

EPA testing detected 13 contaminants in the water serving West Allis. 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 West Allis?

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

What contaminants are in West Allis's water?

The contaminants EPA monitoring detected in West Allis include Copper, TTHM, Lead, Chloroform, Bromodichloromethane. 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.