What was found in Ottumwa'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 | 9000 µg/L 90% of the EPA limit 10000 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019 | 1/3 | SYR4 |
| Fluoride | 700 µg/L 18% of the EPA limit 4000 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 970 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2013 | 2/3 | SYR4 |
| Lithium | 48 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2023
Highest in the city: 420 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2024 | 2/3 | UCMR-5 |
| Lead | 13.91 µg/L 93% of the EPA limit 15 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 335.99 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 2/3 | SYR4 |
| TTHM | 78.23 µg/L 98% of the EPA limit 80 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 84 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 3/3 | SYR4 |
| Barium | 80.4 µg/L 4% of the EPA limit 2000 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2012 | 1/3 | SYR4 |
| Copper | 33.08 µg/L 2.5% of the EPA limit 1300 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 67.7 µg/L — LEISURE LIVING MANF HOME COMMUNITY · 150 people · 2019 | 3/3 | SYR4 |
| Chloroform | 63.63 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 65.3 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 41.4 µg/L 69% of the EPA limit 60 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 26.54 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 29.3 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 14.265 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 23.15 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 22.89 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019 | 2/3 | SYR4 |
| Dibromochloromethane | 5.193 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 19 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 3/3 | SYR4 |
| Xylenes, Total | 9 µg/L 0.1% of the EPA limit 10000 µg/L Highest in the city: WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 1/3 | SYR4 |
| Trichloroacetic Acid | 7.6285 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 8.93 µg/L — LEISURE LIVING MANF HOME COMMUNITY · 150 people · 2019 | 3/3 | SYR4 |
| Bromoform | 0.8060 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 5.58 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 2.414 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019
Highest in the city: 4.05 µg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2019 | 3/3 | SYR4 |
| Arsenic | 4 µg/L 40% of the EPA limit 10 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2012 | 1/3 | SYR4 |
| Monobromoacetic Acid | 3.5325 µg/L No EPA limit set Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019 | 2/3 | SYR4 |
| Ethylbenzene | 2.52 µg/L 0.4% of the EPA limit 700 µg/L Highest in the city: WAPELLO RURAL WATER ASSOC. · 17,263 people · 2016 | 1/3 | SYR4 |
| Atrazine | 0.8880 µg/L 30% of the EPA limit 3 µg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2019 | 1/3 | SYR4 |
| Pfba | 0.0050 µg/L No EPA limit set Highest in the city: WAPELLO RURAL WATER ASSOC. · 17,263 people · 2024 | 1/3 | UCMR-5 |
| Lead | 0.00080 mg/L 5.3% of the EPA limit 0.0150 mg/L Main supplier: OTTUMWA WATER WORKS · 25,529 people · 2025
Highest in the city: 0.0012 mg/L — WAPELLO RURAL WATER ASSOC. · 17,263 people · 2025 | 3/3 | 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 Ottumwa
| Supplier | Population served |
|---|---|
| OTTUMWA WATER WORKS | 25,529 |
| WAPELLO RURAL WATER ASSOC. | 17,263 |
| LEISURE LIVING MANF HOME COMMUNITY | 150 |
Frequently asked questions about Ottumwa tap water
Is Ottumwa tap water safe to drink?
EPA testing detected 23 contaminants in the water serving Ottumwa. 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 Ottumwa?
3 public water suppliers report drinking-water monitoring for Ottumwa, Iowa to the EPA. Each is listed above with its population served.
What contaminants are in Ottumwa's water?
The contaminants EPA monitoring detected in Ottumwa include Nitrate, Fluoride, Lithium, Lead, TTHM. 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.