What was found in Dayton'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 |
|---|---|---|---|
| Nitrate | 1567.5 µg/L 16% of the EPA limit 10000 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Nitrate-Nitrite | 1472 µg/L 15% of the EPA limit 10000 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Fluoride | 977.5 µg/L 24% of the EPA limit 4000 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Chlorite | 519 µg/L 52% of the EPA limit 1000 µg/L Highest in the city: DAYTON VA BLDG 320 POD A · 95 people · 2019 | 2/3 | SYR4 |
| Copper | 68.23 µg/L 5.2% of the EPA limit 1300 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2017
Highest in the city: 381.385 µg/L — DAYTON VA BLDG 410 · 125 people · 2019 | 3/3 | SYR4 |
| Nitrite | 186 µg/L 19% of the EPA limit 1000 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Barium | 67.1 µg/L 3.4% of the EPA limit 2000 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| TTHM | 36.7688 µg/L 46% of the EPA limit 80 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019
Highest in the city: 43.185 µg/L — DAYTON VA BLDG 320 POD A · 95 people · 2019 | 3/3 | SYR4 |
| Gross Beta Particle Activity | 17.2 pCi/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Chloroform | 11.7683 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019
Highest in the city: 16.475 µg/L — DAYTON VA BLDG 320 POD A · 95 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 10.8745 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019
Highest in the city: 13.585 µg/L — DAYTON VA BLDG 320 POD A · 95 people · 2019 | 3/3 | SYR4 |
| Lead | 11.2 µg/L 75% of the EPA limit 15 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2017 | 3/3 | SYR4 |
| Dibromochloromethane | 9.35075 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019
Highest in the city: 10.67 µg/L — DAYTON VA BLDG 320 POD A · 95 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 8.6065 µg/L 14% of the EPA limit 60 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 4.2 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 3.65 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Dibromoacetic Acid | 3.5025 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 3/3 | SYR4 |
| Bromoform | 2.747 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 3/3 | SYR4 |
| Monobromoacetic Acid | 2.38 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Trichloroacetic Acid | 1.51425 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 2/3 | SYR4 |
| Combined Radium (-226 And -228) | 1.3 pCi/L 26% of the EPA limit 5 pCi/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Trichloroethylene | 1.063 µg/L 21% of the EPA limit 5 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| cis-1,2-Dichloroethylene | 0.6665 µg/L 1% of the EPA limit 70 µg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2019 | 1/3 | SYR4 |
| Lead | 0.4700 mg/L 3133% above the EPA limit of 0.0150 mg/L Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2026 | 3/3 | LCR |
| PFHXS | 0.0098 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2023
Highest in the city: 0.0107 µg/L — DAYTON VA BLDG 410 · 125 people · 2025 | 2/3 | UCMR-5 |
| PFOS | 0.0100 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2023
Highest in the city: 0.0105 µg/L — DAYTON VA BLDG 410 · 125 people · 2025 | 2/3 | UCMR-5 |
| Pfpea | 0.0046 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2023 | 2/3 | UCMR-5 |
| Pfhxa | 0.0044 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2023 | 2/3 | UCMR-5 |
| PFBS | 0.0030 µg/L No EPA limit set Main supplier: DAYTON PUBLIC WATER SYSTEM · 141,407 people · 2023 | 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 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 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, Chlorite, Copper. 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.