Is Johnston City, IL Tap Water Safe? Quality & Contaminants

What was found in Johnston City'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
Lead	65.4499999999999 µg/L 436% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: JOHNSTON CITY · 3,509 people · 2017	1/1	SYR4
TTHM	52.27249999999999 µg/L 65% of the EPA limit 80 µg/L Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Copper	41.649999999999984 µg/L 3.2% of the EPA limit 1300 µg/L Main supplier: JOHNSTON CITY · 3,509 people · 2017	1/1	SYR4
Chloroform	40.14749999999999 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Total Haloacetic Acids (HAA5)	36.545 µg/L 61% of the EPA limit 60 µg/L Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Dichloroacetic Acid	26 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Monobromoacetic Acid	19.639999999999997 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Bromodichloromethane	10.746 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Trichloroacetic Acid	7.519000000000002 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Monochloroacetic Acid	4.6259999999999994 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Dibromochloromethane	4.079999999999999 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Dibromoacetic Acid	2.646999999999999 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Bromoform	0.5430 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2019	1/1	SYR4
Lead	0.0077 mg/L 51% of the EPA limit 0.0150 mg/L Main supplier: JOHNSTON CITY · 3,509 people · 2026	1/1	LCR
Pfba	0.0052 µg/L No EPA limit set Main supplier: JOHNSTON CITY · 3,509 people · 2023	1/1	UCMR-5

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 Johnston City

Supplier	Population served
JOHNSTON CITY	3,509

Frequently asked questions about Johnston City tap water

Is Johnston City tap water safe to drink?

EPA testing detected 15 contaminants in the water serving Johnston City. 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 Johnston City?

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

What contaminants are in Johnston City's water?

The contaminants EPA monitoring detected in Johnston City include Lead, TTHM, Copper, 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.