What was found in Ames'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 | 599.5 µg/L 15% of the EPA limit 4000 µg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2012
Highest in the city: 1500 µg/L — SQUAW VALLEY SOUTH SUBDIVISION · 105 people · 2013 | 2/4 | SYR4 |
| Copper | 86.4 µg/L 6.6% of the EPA limit 1300 µg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 942 µg/L — SQUAW VALLEY SOUTH SUBDIVISION · 105 people · 2019 | 4/4 | SYR4 |
| Nitrate | 457 µg/L 4.6% of the EPA limit 10000 µg/L Highest in the city: SQUAW VALLEY SOUTH SUBDIVISION · 105 people · 2019 | 1/4 | SYR4 |
| Barium | 430 µg/L 22% of the EPA limit 2000 µg/L Highest in the city: SQUAW VALLEY SOUTH SUBDIVISION · 105 people · 2013 | 1/4 | SYR4 |
| Nitrite | 96.25 µg/L 9.6% of the EPA limit 1000 µg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019 | 1/4 | SYR4 |
| TTHM | 7.54 µg/L 9.4% of the EPA limit 80 µg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 70.3 µg/L — MAPLE GROVE MHC · 160 people · 2019 | 3/4 | SYR4 |
| Chloroform | 6.36 µg/L No EPA limit set Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 53.1 µg/L — MAPLE GROVE MHC · 160 people · 2019 | 3/4 | SYR4 |
| Lithium | 26 µg/L No EPA limit set Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2025
Highest in the city: 29 µg/L — ISU · 42,000 people · 2025 | 2/4 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 6 µg/L 10% of the EPA limit 60 µg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 23.2 µg/L — MAPLE GROVE MHC · 160 people · 2019 | 3/4 | SYR4 |
| Lead | 18.7 µg/L 125% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 22.645 µg/L — ISU · 42,000 people · 2018 | 4/4 | SYR4 |
| Dichloroacetic Acid | 4 µg/L No EPA limit set Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 17.1 µg/L — MAPLE GROVE MHC · 160 people · 2019 | 3/4 | SYR4 |
| Bromodichloromethane | 1.16 µg/L No EPA limit set Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 13.1 µg/L — MAPLE GROVE MHC · 160 people · 2019 | 3/4 | SYR4 |
| Dibromochloromethane | 5.86 µg/L No EPA limit set Highest in the city: MAPLE GROVE MHC · 160 people · 2019 | 1/4 | SYR4 |
| Monochloroacetic Acid | 2 µg/L No EPA limit set Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 4.6275 µg/L — ISU · 42,000 people · 2019 | 3/4 | SYR4 |
| Trichloroacetic Acid | 3 µg/L No EPA limit set Highest in the city: MAPLE GROVE MHC · 160 people · 2019 | 2/4 | SYR4 |
| Bromoform | 2.67 µg/L No EPA limit set Highest in the city: ISU · 42,000 people · 2019 | 2/4 | SYR4 |
| Dibromoacetic Acid | 2 µg/L No EPA limit set Highest in the city: MAPLE GROVE MHC · 160 people · 2019 | 2/4 | SYR4 |
| Monobromoacetic Acid | 1 µg/L No EPA limit set Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2019
Highest in the city: 1.78 µg/L — ISU · 42,000 people · 2019 | 2/4 | SYR4 |
| Combined Radium (-226 And -228) | 1.58 pCi/L 32% of the EPA limit 5 pCi/L Highest in the city: SQUAW VALLEY SOUTH SUBDIVISION · 105 people · 2018 | 1/4 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: AMES WATER TREATMENT PLANT · 55,177 people · 2025
Highest in the city: 0.0300 mg/L — SQUAW VALLEY SOUTH SUBDIVISION · 105 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 Ames
| Supplier | Population served |
|---|---|
| AMES WATER TREATMENT PLANT | 55,177 |
| ISU | 42,000 |
| MAPLE GROVE MHC | 160 |
| SQUAW VALLEY SOUTH SUBDIVISION | 105 |
Frequently asked questions about Ames tap water
Is Ames tap water safe to drink?
EPA testing detected 20 contaminants in the water serving Ames. 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 Ames?
4 public water suppliers report drinking-water monitoring for Ames, Iowa to the EPA. Each is listed above with its population served.
What contaminants are in Ames's water?
The contaminants EPA monitoring detected in Ames include Fluoride, Copper, Nitrate, 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.