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 |
|---|---|---|---|
| Fluoride | 277.5 µg/L 6.9% of the EPA limit 4000 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2018
Highest in the city: 1535 µg/L — NORTHPARK WSC · 279 people · 2018 | 3/4 | SYR4 |
| Copper | 115.9 µg/L 8.9% of the EPA limit 1300 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019
Highest in the city: 826.25 µg/L — NORTHPARK WSC · 279 people · 2018 | 3/4 | SYR4 |
| Barium | 196.9 µg/L 9.8% of the EPA limit 2000 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019 | 3/4 | SYR4 |
| Nitrate | 180 µg/L 1.8% of the EPA limit 10000 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019 | 3/4 | SYR4 |
| Nitrate-Nitrite | 180 µg/L 1.8% of the EPA limit 10000 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019 | 2/4 | SYR4 |
| TTHM | 63.485 µg/L 79% of the EPA limit 80 µg/L Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 24.255 µg/L 40% of the EPA limit 60 µg/L Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Selenium | 22.71 µg/L 45% of the EPA limit 50 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019 | 1/4 | SYR4 |
| Bromodichloromethane | 21.44 µg/L No EPA limit set Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Dibromochloromethane | 21.16 µg/L No EPA limit set Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Chloroform | 17.44 µg/L No EPA limit set Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Lead | 16.628 µg/L 111% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019 | 3/4 | SYR4 |
| Lithium | 16.5 µg/L No EPA limit set Main supplier: CITY OF DAYTON · 15,393 people · 2023 | 1/4 | UCMR-5 |
| Dichloroacetic Acid | 13.295 µg/L No EPA limit set Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Trichloroacetic Acid | 7.68 µg/L No EPA limit set Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Bromoform | 5.28 µg/L No EPA limit set Highest in the city: HUNTERS COVE SEC 1 · 64 people · 2019 | 2/4 | SYR4 |
| Arsenic | 3.17 µg/L 32% of the EPA limit 10 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019
Highest in the city: 5.21 µg/L — NORTHPARK WSC · 279 people · 2019 | 3/4 | SYR4 |
| Dibromoacetic Acid | 4.615 µg/L No EPA limit set Highest in the city: NORTHPARK WSC · 279 people · 2019 | 2/4 | SYR4 |
| Combined Radium (-226 And -228) | 4.2 pCi/L 84% of the EPA limit 5 pCi/L Main supplier: CITY OF DAYTON · 15,393 people · 2017 | 2/4 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.9 pCi/L 19% of the EPA limit 15 pCi/L Main supplier: CITY OF DAYTON · 15,393 people · 2017 | 1/4 | SYR4 |
| Combined Uranium | 2.79 µg/L 9.3% of the EPA limit 30 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2017 | 1/4 | SYR4 |
| Xylenes, Total | 1.54 µg/L 0% of the EPA limit 10000 µg/L Main supplier: CITY OF DAYTON · 15,393 people · 2019 | 1/4 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CITY OF DAYTON · 15,393 people · 2025
Highest in the city: 0.00099 mg/L — NORTHPARK WSC · 279 people · 2025 | 4/4 | 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 Dayton
| Supplier | Population served |
|---|---|
| CITY OF DAYTON | 15,393 |
| NORTHPARK WSC | 279 |
| HUNTERS COVE SEC 1 | 64 |
| CITY OF DAYTON LAKES | 36 |
Frequently asked questions about Dayton tap water
Is Dayton tap water safe to drink?
EPA testing detected 23 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?
4 public water suppliers report drinking-water monitoring for Dayton, Texas 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 Fluoride, Copper, Barium, Nitrate, Nitrate-Nitrite. 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.