Is Chicago, IL Tap Water Safe? Quality & Contaminants

What was found in Chicago'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
Fluoride	950 µg/L 24% of the EPA limit 4000 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Nitrate	436.7 µg/L 4.4% of the EPA limit 10000 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Nitrate-Nitrite	427.5 µg/L 4.3% of the EPA limit 10000 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019	2/3	SYR4
Copper	157 µg/L 12% of the EPA limit 1300 µg/L Main supplier: CHICAGO · 2,721,308 people · 2018 Highest in the city: 172.5 µg/L — BLACKHAWK ESTATES LLC · 1,238 people · 2018	3/3	SYR4
Barium	22.4 µg/L 1.1% of the EPA limit 2000 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019 Highest in the city: 49.625 µg/L — WILLOWAY TERRACE MHP · 900 people · 2018	3/3	SYR4
Lead	11 µg/L 73% of the EPA limit 15 µg/L Main supplier: CHICAGO · 2,721,308 people · 2018 Highest in the city: 34.778 µg/L — BLACKHAWK ESTATES LLC · 1,238 people · 2018	3/3	SYR4
TTHM	32.895 µg/L 41% of the EPA limit 80 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Total Haloacetic Acids (HAA5)	17.6 µg/L 29% of the EPA limit 60 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Chloroform	17.2 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Bromodichloromethane	10.8 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Dichloroacetic Acid	9.1 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019	3/3	SYR4
Trichloroacetic Acid	7.8 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019	1/3	SYR4
Monochloroacetic Acid	4.8 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019 Highest in the city: 7.5265 µg/L — WILLOWAY TERRACE MHP · 900 people · 2019	2/3	SYR4
Dibromochloromethane	5.9 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019	2/3	SYR4
Selenium	2.48 µg/L 5% of the EPA limit 50 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019	1/3	SYR4
Combined Radium (-226 And -228)	0.8230 pCi/L 16% of the EPA limit 5 pCi/L Main supplier: CHICAGO · 2,721,308 people · 2014 Highest in the city: 1.942 pCi/L — BLACKHAWK ESTATES LLC · 1,238 people · 2016	3/3	SYR4
Arsenic	0.7528 µg/L 7.5% of the EPA limit 10 µg/L Main supplier: CHICAGO · 2,721,308 people · 2019 Highest in the city: 1.78585 µg/L — WILLOWAY TERRACE MHP · 900 people · 2018	3/3	SYR4
Dibromoacetic Acid	1.7 µg/L No EPA limit set Main supplier: CHICAGO · 2,721,308 people · 2019	2/3	SYR4
Lead	0.0070 mg/L 47% of the EPA limit 0.0150 mg/L Main supplier: CHICAGO · 2,721,308 people · 2026	3/3	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 Chicago

Supplier	Population served
CHICAGO	2,721,308
BLACKHAWK ESTATES LLC	1,238
WILLOWAY TERRACE MHP	900

Frequently asked questions about Chicago tap water

Is Chicago tap water safe to drink?

EPA testing detected 19 contaminants in the water serving Chicago. 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 Chicago?

3 public water suppliers report drinking-water monitoring for Chicago, Illinois to the EPA. Each is listed above with its population served.

What contaminants are in Chicago's water?

The contaminants EPA monitoring detected in Chicago include Fluoride, Nitrate, Nitrate-Nitrite, Copper, Barium. 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.