What was found in Mankato'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-Nitrite | 3965 µg/L 40% of the EPA limit 10000 µg/L Main supplier: Mankato · 42,803 people · 2019 | 6/8 | SYR4 |
| Fluoride | 1100 µg/L 28% of the EPA limit 4000 µg/L Main supplier: Mankato · 42,803 people · 2019
Highest in the city: 1640 µg/L — South Bend Township · 325 people · 2019 | 6/8 | SYR4 |
| Copper | 111.95 µg/L 8.6% of the EPA limit 1300 µg/L Main supplier: Mankato · 42,803 people · 2019
Highest in the city: 709.9 µg/L — GC Mankato Hill LLC · 140 people · 2019 | 8/8 | SYR4 |
| Cyanide | 80 µg/L 40% of the EPA limit 200 µg/L Highest in the city: Hillcrest Health Care Center · 94 people · 2015 | 1/8 | SYR4 |
| Barium | 31.25 µg/L 1.6% of the EPA limit 2000 µg/L Main supplier: Mankato · 42,803 people · 2017
Highest in the city: 50.6 µg/L — Riverbend Homes and More · 60 people · 2017 | 6/8 | SYR4 |
| Lead | 4.04 µg/L 27% of the EPA limit 15 µg/L Main supplier: Mankato · 42,803 people · 2019
Highest in the city: 44.245 µg/L — GC Mankato Hill LLC · 140 people · 2019 | 8/8 | SYR4 |
| Chloroform | 37.8 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 6/8 | SYR4 |
| Lithium | 34.8 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2023 | 1/8 | UCMR-5 |
| Bromodichloromethane | 18.4 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 2/8 | SYR4 |
| Chromium | 0.4710 µg/L 0.5% of the EPA limit 100 µg/L Main supplier: Mankato · 42,803 people · 2017
Highest in the city: 15.1 µg/L — Rapidan Development Company, Inc. · 164 people · 2015 | 2/8 | SYR4 |
| Dichloroacetic Acid | 15 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 2/8 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.78 pCi/L 32% of the EPA limit 15 pCi/L Main supplier: Mankato · 42,803 people · 2017
Highest in the city: 11.69 pCi/L — Rapidan Development Company, Inc. · 164 people · 2018 | 7/8 | SYR4 |
| Dibromochloromethane | 9.44 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 1/8 | SYR4 |
| Arsenic | 4.736 µg/L 47% of the EPA limit 10 µg/L Main supplier: Mankato · 42,803 people · 2017
Highest in the city: 7.7695 µg/L — GC Mankato Hill LLC · 140 people · 2019 | 5/8 | SYR4 |
| Trichloroacetic Acid | 7 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 1/8 | SYR4 |
| Dibromoacetic Acid | 3 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 1/8 | SYR4 |
| Bromoform | 2.2 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 1/8 | SYR4 |
| Monobromoacetic Acid | 1.3 µg/L No EPA limit set Main supplier: Mankato · 42,803 people · 2019 | 1/8 | SYR4 |
| Toluene | 0.9800 µg/L 0.1% of the EPA limit 1000 µg/L Highest in the city: Hillcrest Health Care Center · 94 people · 2018 | 1/8 | SYR4 |
| Ethylbenzene | 0.5100 µg/L 0.1% of the EPA limit 700 µg/L Highest in the city: South Bend Township · 325 people · 2019 | 1/8 | SYR4 |
| Atrazine | 0.1000 µg/L 3.3% of the EPA limit 3 µg/L Main supplier: Mankato · 42,803 people · 2019 | 1/8 | SYR4 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: Mankato · 42,803 people · 2025
Highest in the city: 0.0050 mg/L — GC Mankato Hill LLC · 140 people · 2025 | 8/8 | 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 Mankato
| Supplier | Population served |
|---|---|
| Mankato | 42,803 |
| South Bend Township | 325 |
| Skyline | 289 |
| Rapidan Development Company, Inc. | 164 |
| GC Mankato Hill LLC | 140 |
| Hillcrest Health Care Center | 94 |
| Riverbend Homes and More | 60 |
| Terrace View East Condominium Assoc. | 38 |
Frequently asked questions about Mankato tap water
Is Mankato tap water safe to drink?
EPA testing detected 22 contaminants in the water serving Mankato. 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 Mankato?
8 public water suppliers report drinking-water monitoring for Mankato, Minnesota to the EPA. Each is listed above with its population served.
What contaminants are in Mankato's water?
The contaminants EPA monitoring detected in Mankato include Nitrate-Nitrite, Fluoride, Copper, Cyanide, 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.