Is Dayton, OH Tap Water Safe? Quality & Contaminants

What was found in Dayton'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	1900 µg/L 19% of the EPA limit 10000 µg/L	1/3	SYR4
Nitrate-Nitrite	1790 µg/L 18% of the EPA limit 10000 µg/L	1/3	SYR4
Fluoride	1000 µg/L 25% of the EPA limit 4000 µg/L	1/3	SYR4
Copper	622 µg/L 48% of the EPA limit 1300 µg/L	3/3	SYR4
Chlorite	520 µg/L 52% of the EPA limit 1000 µg/L	2/3	SYR4
Nitrite	186 µg/L 19% of the EPA limit 1000 µg/L	1/3	SYR4
Barium	94.2 µg/L 4.7% of the EPA limit 2000 µg/L	1/3	SYR4
TTHM	46.875 µg/L 59% of the EPA limit 80 µg/L	3/3	SYR4
Total Haloacetic Acids (HAA5)	21.3 µg/L 36% of the EPA limit 60 µg/L	3/3	SYR4
Gross Beta Particle Activity	20 pCi/L No EPA limit set	1/3	SYR4
Chloroform	19.635 µg/L No EPA limit set	3/3	SYR4
Bromodichloromethane	13.9 µg/L No EPA limit set	3/3	SYR4
Lead	13.9 µg/L 93% of the EPA limit 15 µg/L	3/3	SYR4
Dibromochloromethane	13.045 µg/L No EPA limit set	3/3	SYR4
Dichloroacetic Acid	5.9 µg/L No EPA limit set	3/3	SYR4
Bromoform	5.837 µg/L No EPA limit set	3/3	SYR4
Dibromoacetic Acid	5.8 µg/L No EPA limit set	3/3	SYR4
Trichloroacetic Acid	4.4 µg/L No EPA limit set	2/3	SYR4
Monochloroacetic Acid	3.7 µg/L No EPA limit set	1/3	SYR4
Monobromoacetic Acid	2.5 µg/L No EPA limit set	1/3	SYR4
Combined Radium (-226 And -228)	1.3 pCi/L 26% of the EPA limit 5 pCi/L	1/3	SYR4
Trichloroethylene	1.063 µg/L 21% of the EPA limit 5 µg/L	1/3	SYR4
cis-1,2-Dichloroethylene	0.6730 µg/L 1% of the EPA limit 70 µg/L	1/3	SYR4
Lead	0.4700 mg/L 3133% above the EPA limit of 0.0150 mg/L	3/3	LCR
PFHXS	0.0107 µg/L No EPA limit set	2/3	UCMR-5
PFOS	0.0105 µg/L No EPA limit set	2/3	UCMR-5
Pfpea	0.0046 µg/L No EPA limit set	2/3	UCMR-5
Pfhxa	0.0044 µg/L No EPA limit set	2/3	UCMR-5
PFBS	0.0030 µg/L No EPA limit set	1/3	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 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 Dayton

Supplier	Population served
DAYTON PUBLIC WATER SYSTEM	141,407
DAYTON VA BLDG 410	125
DAYTON VA BLDG 320 POD A	95

Frequently asked questions about Dayton tap water

Is Dayton tap water safe to drink?

EPA testing detected 29 contaminants in the water serving Dayton. 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 Dayton?

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

What contaminants are in Dayton's water?

The contaminants EPA monitoring detected in Dayton include Nitrate, Nitrate-Nitrite, Fluoride, Copper, Chlorite. 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.