Is Columbus, OH Tap Water Safe? Quality & Contaminants

What was found in Columbus's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

Contaminant	Level vs EPA limit	Suppliers	Source
Nitrate	12500 µg/L 125% of the EPA limit, in the worst sample — 10000 µg/L	2/5	SYR4
Nitrate-Nitrite	12500 µg/L 125% of the EPA limit, in the worst sample — 10000 µg/L	2/5	SYR4
Fluoride	1270 µg/L 32% of the EPA limit 4000 µg/L	2/5	SYR4
Copper	758 µg/L 58% of the EPA limit 1300 µg/L	4/5	SYR4
TTHM	128 µg/L 160% of the EPA limit, in the worst sample — 80 µg/L	4/5	SYR4
Bromodichloromethane	97 µg/L No EPA limit set	4/5	SYR4
Chloroform	94 µg/L No EPA limit set	4/5	SYR4
Total Haloacetic Acids (HAA5)	80.1 µg/L 134% of the EPA limit, in the worst sample — 60 µg/L	3/5	SYR4
Lead	39.5 µg/L 263% of the EPA limit, in the worst sample — 15 µg/L	4/5	SYR4
Dichloroacetic Acid	39 µg/L No EPA limit set	4/5	SYR4
Trichloroacetic Acid	37.7 µg/L No EPA limit set	4/5	SYR4
Barium	26.2 µg/L 1.3% of the EPA limit 2000 µg/L	2/5	SYR4
Monochloroacetic Acid	21.7 µg/L No EPA limit set	3/5	SYR4
Dibromoacetic Acid	14.6 µg/L No EPA limit set	3/5	SYR4
Dibromochloromethane	13.9 µg/L No EPA limit set	4/5	SYR4
Bromoform	9.1 µg/L No EPA limit set	3/5	SYR4
Arsenic	5.5 µg/L 55% of the EPA limit 10 µg/L	1/5	SYR4
Atrazine	2.8 µg/L 93% of the EPA limit 3 µg/L	1/5	SYR4
Monobromoacetic Acid	2.3 µg/L No EPA limit set	1/5	SYR4
Simazine	0.3900 µg/L 9.8% of the EPA limit 4 µg/L	1/5	SYR4
Lasso	0.3700 µg/L 19% of the EPA limit 2 µg/L	1/5	SYR4
Pfhxa	0.0220 µg/L No EPA limit set	2/5	UCMR-5
Pfba	0.0170 µg/L No EPA limit set	2/5	UCMR-5
Pfpea	0.0170 µg/L No EPA limit set	2/5	UCMR-5
PFBS	0.0111 µg/L No EPA limit set	2/5	UCMR-5
PFOA	0.0072 µg/L No EPA limit set	2/5	UCMR-5
Pfhpa	0.0054 µg/L No EPA limit set	2/5	UCMR-5
Lead	0.0018 mg/L 12% of the EPA limit 0.0150 mg/L	4/5	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 single worst sample on record — 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 Columbus

Supplier	Population served
COLUMBUS PUBLIC WATER SYSTEM	1,305,946
SANITARY DISTRICT #4	8,575
TIMBERLAKE WATER SYSTEM	1,600
GALLOWAY WATER SYSTEM PWS	350
LEONARD PARK PWS	266

Frequently asked questions about Columbus tap water

Is Columbus tap water safe to drink?

EPA testing detected 28 contaminants in the water serving Columbus. 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 Columbus?

5 public water suppliers report drinking-water monitoring for Columbus, Ohio to the EPA. Each is listed above with its population served.

What contaminants are in Columbus's water?

The contaminants EPA monitoring detected in Columbus include Nitrate, Nitrate-Nitrite, Fluoride, Copper, TTHM. The full list, with the highest level found 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.