What was found in Oklahoma 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 |
|---|---|---|---|
| Nitrate | 439.75 µg/L 4.4% of the EPA limit 10000 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019
Highest in the city: 2420 µg/L — HILLTOP MHP · 125 people · 2019 | 5/6 | SYR4 |
| Nitrate-Nitrite | 442 µg/L 4.4% of the EPA limit 10000 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019
Highest in the city: 2390 µg/L — HILLCREST MHP · 400 people · 2019 | 6/6 | SYR4 |
| Fluoride | 845 µg/L 21% of the EPA limit 4000 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2013 | 4/6 | SYR4 |
| Barium | 56.23 µg/L 2.8% of the EPA limit 2000 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2013
Highest in the city: 598.2 µg/L — TINKER AIR FORCE BASE · 24,645 people · 2019 | 6/6 | SYR4 |
| Nitrite | 58.15 µg/L 5.8% of the EPA limit 1000 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019
Highest in the city: 339.5 µg/L — HOLLIDAY OUTT MHP · 100 people · 2012 | 3/6 | SYR4 |
| Copper | 260.926 µg/L 20% of the EPA limit 1300 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019
Highest in the city: 300.65 µg/L — TINKER AIR FORCE BASE · 24,645 people · 2019 | 6/6 | SYR4 |
| TTHM | 76.688 µg/L 96% of the EPA limit 80 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 4/6 | SYR4 |
| Lithium | 67.8 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2024 | 2/6 | UCMR-5 |
| Chloroform | 57.322 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 4/6 | SYR4 |
| Total Haloacetic Acids (HAA5) | 46.716 µg/L 78% of the EPA limit 60 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 3/6 | SYR4 |
| Combined Uranium | 35.4 µg/L 118% of the EPA limit, at the 95th percentile of samples — 30 µg/L Highest in the city: HOLLIDAY OUTT MHP · 100 people · 2018 | 4/6 | SYR4 |
| Bromate | 34.14 µg/L 341% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 1/6 | SYR4 |
| Lead | 13.313 µg/L 89% of the EPA limit 15 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019
Highest in the city: 29.4 µg/L — TINKER AIR FORCE BASE · 24,645 people · 2019 | 3/6 | SYR4 |
| Dichloroacetic Acid | 26.352 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 3/6 | SYR4 |
| Chromium | 20.8 µg/L 21% of the EPA limit 100 µg/L Highest in the city: TINKER AIR FORCE BASE · 24,645 people · 2019 | 1/6 | SYR4 |
| Trichloroacetic Acid | 20.705 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 2/6 | SYR4 |
| Gross Alpha, Excl. Radon And U | 18.6 pCi/L 124% of the EPA limit, at the 95th percentile of samples — 15 pCi/L Highest in the city: HOLLIDAY OUTT MHP · 100 people · 2018 | 4/6 | SYR4 |
| Bromodichloromethane | 17.3725 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 3/6 | SYR4 |
| Gross Beta Particle Activity | 8.4806 pCi/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2018
Highest in the city: 14.68 pCi/L — HOLLIDAY OUTT MHP · 100 people · 2018 | 5/6 | SYR4 |
| Arsenic | 14.39 µg/L 144% of the EPA limit, at the 95th percentile of samples — 10 µg/L Highest in the city: HOLLIDAY OUTT MHP · 100 people · 2018 | 2/6 | SYR4 |
| Dibromochloromethane | 8.63 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 5/6 | SYR4 |
| Bromoform | 7.825 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 5/6 | SYR4 |
| Carbon Tetrachloride | 6.4 µg/L 128% of the EPA limit, at the 95th percentile of samples — 5 µg/L Highest in the city: TINKER AIR FORCE BASE · 24,645 people · 2019 | 1/6 | SYR4 |
| Monobromoacetic Acid | 6.284 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 1/6 | SYR4 |
| Monochloroacetic Acid | 4.499 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 1/6 | SYR4 |
| Dibromoacetic Acid | 4.2255 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 2/6 | SYR4 |
| Combined Radium (-226 And -228) | 3.616 pCi/L 72% of the EPA limit 5 pCi/L Highest in the city: TINKER AIR FORCE BASE · 24,645 people · 2019 | 4/6 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 2.59 µg/L 43% of the EPA limit 6 µg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2019 | 2/6 | SYR4 |
| Toluene | 1 µg/L 0.1% of the EPA limit 1000 µg/L Highest in the city: HILLCREST MHP · 400 people · 2017 | 2/6 | SYR4 |
| Trichloroethylene | 0.9000 µg/L 18% of the EPA limit 5 µg/L Highest in the city: TINKER AIR FORCE BASE · 24,645 people · 2019 | 1/6 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: OKLAHOMA CITY · 644,000 people · 2025
Highest in the city: 0.0435 mg/L — HOLLIDAY OUTT MHP · 100 people · 2025 | 6/6 | LCR |
| PFHXS | 0.0052 µg/L No EPA limit set Highest in the city: TINKER AIR FORCE BASE · 24,645 people · 2025 | 1/6 | UCMR-5 |
| Pfpea | 0.0047 µg/L No EPA limit set Main supplier: OKLAHOMA CITY · 644,000 people · 2024 | 1/6 | 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 Oklahoma City
| Supplier | Population served |
|---|---|
| OKLAHOMA CITY | 644,000 |
| TINKER AIR FORCE BASE | 24,645 |
| HILLCREST MHP | 400 |
| ABES RV PARK | 175 |
| HILLTOP MHP | 125 |
| HOLLIDAY OUTT MHP | 100 |
Frequently asked questions about Oklahoma City tap water
Is Oklahoma City tap water safe to drink?
EPA testing detected 33 contaminants in the water serving Oklahoma 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 Oklahoma City?
6 public water suppliers report drinking-water monitoring for Oklahoma City, Oklahoma to the EPA. Each is listed above with its population served.
What contaminants are in Oklahoma City's water?
The contaminants EPA monitoring detected in Oklahoma City include Nitrate, Nitrate-Nitrite, Fluoride, Barium, 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.