What was found in Marshalltown'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 | 7075 µg/L 71% of the EPA limit 10000 µg/L Highest in the city: MARSHALLTOWN ESTATES · 382 people · 2019 | 1/3 | SYR4 |
| Fluoride | 750 µg/L 19% of the EPA limit 4000 µg/L Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2013 | 2/3 | SYR4 |
| Copper | 30 µg/L 2.3% of the EPA limit 1300 µg/L Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2019
Highest in the city: 321.9 µg/L — MARSHALLTOWN ESTATES · 382 people · 2018 | 3/3 | SYR4 |
| Chlorite | 190 µg/L 19% of the EPA limit 1000 µg/L Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2012 | 1/3 | SYR4 |
| Barium | 114 µg/L 5.7% of the EPA limit 2000 µg/L Highest in the city: MARSHALLTOWN ESTATES · 382 people · 2015 | 1/3 | SYR4 |
| Lithium | 20 µg/L No EPA limit set Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2025 | 1/3 | UCMR-5 |
| Lead | 5.05 µg/L 34% of the EPA limit 15 µg/L Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2019
Highest in the city: 8.52 µg/L — MARSHALLTOWN ESTATES · 382 people · 2018 | 3/3 | SYR4 |
| Monochloroacetic Acid | 3 µg/L No EPA limit set Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2019 | 2/3 | SYR4 |
| Selenium | 1.8 µg/L 3.6% of the EPA limit 50 µg/L Highest in the city: MARSHALLTOWN ESTATES · 382 people · 2015 | 1/3 | SYR4 |
| Dichloroacetic Acid | 1.65 µg/L No EPA limit set Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2019
Highest in the city: 1.79 µg/L — SUNSET VILLAGE · 528 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 1.1 µg/L No EPA limit set Highest in the city: SUNSET VILLAGE · 528 people · 2019 | 1/3 | SYR4 |
| Dibromochloromethane | 0.9000 µg/L No EPA limit set Highest in the city: MARSHALLTOWN ESTATES · 382 people · 2017 | 1/3 | SYR4 |
| Dibromoacetic Acid | 0.6000 µg/L No EPA limit set Highest in the city: SUNSET VILLAGE · 528 people · 2019 | 1/3 | SYR4 |
| Chloroform | 0.5000 µg/L No EPA limit set Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2019 | 1/3 | SYR4 |
| Xylenes, Total | 0.5000 µg/L 0% of the EPA limit 10000 µg/L Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2017 | 1/3 | SYR4 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: MARSHALLTOWN WATER WORKS · 27,680 people · 2025
Highest in the city: 0.0030 mg/L — MARSHALLTOWN ESTATES · 382 people · 2024 | 3/3 | LCR |
Water suppliers serving Marshalltown
| Supplier | Population served |
|---|---|
| MARSHALLTOWN WATER WORKS | 27,680 |
| SUNSET VILLAGE | 528 |
| MARSHALLTOWN ESTATES | 382 |
Frequently asked questions about Marshalltown tap water
Is Marshalltown tap water safe to drink?
EPA testing detected 16 contaminants in the water serving Marshalltown. 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 Marshalltown?
3 public water suppliers report drinking-water monitoring for Marshalltown, Iowa to the EPA. Each is listed above with its population served.
What contaminants are in Marshalltown's water?
The contaminants EPA monitoring detected in Marshalltown include Nitrate, Fluoride, Copper, Chlorite, Barium. 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.