What was found in Waterloo'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 | 8467.5 µg/L 85% of the EPA limit 10000 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Fluoride | 1000 µg/L 25% of the EPA limit 4000 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Copper | 291.5 µg/L 22% of the EPA limit 1300 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Barium | 220.2 µg/L 11% of the EPA limit 2000 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2012 | 1/1 | SYR4 |
| Lithium | 20 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2024 | 1/1 | UCMR-5 |
| TTHM | 12.75 µg/L 16% of the EPA limit 80 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Monochloroacetic Acid | 9.81 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Lead | 9.12 µg/L 61% of the EPA limit 15 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 6.8055 µg/L 11% of the EPA limit 60 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Chloroform | 5.88 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Bromodichloromethane | 3.745 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Selenium | 3.68 µg/L 7.4% of the EPA limit 50 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2012 | 1/1 | SYR4 |
| Dichloroacetic Acid | 3.2425 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Combined Radium (-226 And -228) | 2.9 pCi/L 58% of the EPA limit 5 pCi/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2018 | 1/1 | SYR4 |
| Dibromochloromethane | 2.755 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Trichloroethylene | 2.557 µg/L 51% of the EPA limit 5 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2018 | 1/1 | SYR4 |
| Tetrachloroethylene | 2.46 µg/L 49% of the EPA limit 5 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 1.665 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Monobromoacetic Acid | 1.57 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Trichloroacetic Acid | 1.32 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| 1,1,1-Trichloroethane | 1.056 µg/L 0.5% of the EPA limit 200 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2018 | 1/1 | SYR4 |
| cis-1,2-Dichloroethylene | 0.9950 µg/L 1.4% of the EPA limit 70 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2018 | 1/1 | SYR4 |
| Bromoform | 0.9725 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2019 | 1/1 | SYR4 |
| Antimony, Total | 0.5000 µg/L 8.3% of the EPA limit 6 µg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2012 | 1/1 | SYR4 |
| PFHXS | 0.0130 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2024 | 1/1 | UCMR-5 |
| Pfpea | 0.0048 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2024 | 1/1 | UCMR-5 |
| PFBS | 0.0032 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2024 | 1/1 | UCMR-5 |
| Pfhxa | 0.0031 µg/L No EPA limit set Main supplier: WATERLOO WATER WORKS · 69,504 people · 2024 | 1/1 | UCMR-5 |
| Lead | 0.0018 mg/L 12% of the EPA limit 0.0150 mg/L Main supplier: WATERLOO WATER WORKS · 69,504 people · 2025 | 1/1 | 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 Waterloo
| Supplier | Population served |
|---|---|
| WATERLOO WATER WORKS | 69,504 |
Frequently asked questions about Waterloo tap water
Is Waterloo tap water safe to drink?
EPA testing detected 29 contaminants in the water serving Waterloo. 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 Waterloo?
1 public water supplier report drinking-water monitoring for Waterloo, Iowa to the EPA. Each is listed above with its population served.
What contaminants are in Waterloo's water?
The contaminants EPA monitoring detected in Waterloo include Nitrate, Fluoride, Copper, Barium, Lithium. 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.