What was found in Mexico'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 | 1244 µg/L 31% of the EPA limit 4000 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 1286.5 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Nitrate | 320 µg/L 3.2% of the EPA limit 10000 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 1/2 | SYR4 |
| Nitrate-Nitrite | 316.5 µg/L 3.2% of the EPA limit 10000 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 1/2 | SYR4 |
| Copper | 110.3 µg/L 8.5% of the EPA limit 1300 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 169.45 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Lithium | 146 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2024 | 1/2 | UCMR-5 |
| Barium | 46.55 µg/L 2.3% of the EPA limit 2000 µg/L Highest in the city: AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 1/2 | SYR4 |
| TTHM | 33.805 µg/L 42% of the EPA limit 80 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 12.925 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 4.85 µg/L 8.1% of the EPA limit 60 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 12.5 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Bromoform | 11.59 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 7.77 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 2/2 | SYR4 |
| Lead | 5.25 µg/L 35% of the EPA limit 15 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 7.3145 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 1.98 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 6.9485 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Gross Alpha, Excl. Radon And U | 6.285 pCi/L 42% of the EPA limit 15 pCi/L Highest in the city: AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 1/2 | SYR4 |
| Chromium | 1.385 µg/L 1.4% of the EPA limit 100 µg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 5.929 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 2.9 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 3.7295 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 3.2 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019 | 1/2 | SYR4 |
| Chloroform | 2.96 µg/L No EPA limit set Main supplier: MO AMERICAN MEXICO · 13,000 people · 2019
Highest in the city: 3.1955 µg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 2/2 | SYR4 |
| Combined Radium (-226 And -228) | 2.165 pCi/L 43% of the EPA limit 5 pCi/L Highest in the city: AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 1/2 | SYR4 |
| Trichloroacetic Acid | 1.16 µg/L No EPA limit set Highest in the city: AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2019 | 1/2 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: MO AMERICAN MEXICO · 13,000 people · 2025
Highest in the city: 0.0018 mg/L — AUDRAIN COUNTY CONSOLIDATED PWSD 2 · 4,016 people · 2025 | 2/2 | 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 Mexico
| Supplier | Population served |
|---|---|
| MO AMERICAN MEXICO | 13,000 |
| AUDRAIN COUNTY CONSOLIDATED PWSD 2 | 4,016 |
Frequently asked questions about Mexico tap water
Is Mexico tap water safe to drink?
EPA testing detected 21 contaminants in the water serving Mexico. 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 Mexico?
2 public water suppliers report drinking-water monitoring for Mexico, Missouri to the EPA. Each is listed above with its population served.
What contaminants are in Mexico's water?
The contaminants EPA monitoring detected in Mexico include Fluoride, Nitrate, Nitrate-Nitrite, Copper, 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.