What was found in Mercedes'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 |
|---|---|---|---|
| Copper | 896.9999999999905 µg/L 69% of the EPA limit 1300 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2017
Highest in the city: 2533.9999999999986 µg/L — LLANO GRANDE LAKE PARK EAST · 1,300 people · 2019 | 3/3 | SYR4 |
| Fluoride | 1056.9999999999998 µg/L 26% of the EPA limit 4000 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Nitrate | 860 µg/L 8.6% of the EPA limit 10000 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Cyanide | 108 µg/L 54% of the EPA limit 200 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| TTHM | 103.34999999999994 µg/L 129% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019
Highest in the city: 103.94999999999999 µg/L — LLANO GRANDE LAKE PARK EAST · 1,300 people · 2019 | 3/3 | SYR4 |
| Barium | 101.4 µg/L 5.1% of the EPA limit 2000 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Lithium | 61.4 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2023 | 1/3 | UCMR-5 |
| Bromoform | 37.845 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Dibromochloromethane | 35.77800000000001 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 34.62 µg/L 58% of the EPA limit 60 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Lead | 15.199999999999996 µg/L 101% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2017
Highest in the city: 24.679999999999996 µg/L — LLANO GRANDE LAKE PARK WEST · 300 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 24.135000000000005 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 12.999999999999993 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019
Highest in the city: 23.869999999999997 µg/L — LLANO GRANDE LAKE PARK EAST · 1,300 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 17.549999999999994 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Monobromoacetic Acid | 17.3 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 2/3 | SYR4 |
| Chloroform | 12.390000000000004 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 10.319999999999999 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019
Highest in the city: 10.859999999999998 µg/L — LLANO GRANDE LAKE PARK EAST · 1,300 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 7.1 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 3/3 | SYR4 |
| Gross Beta Particle Activity | 6.8 pCi/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2017 | 1/3 | SYR4 |
| Selenium | 5.1899999999999995 µg/L 10% of the EPA limit 50 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Arsenic | 4.1499999999999995 µg/L 41% of the EPA limit 10 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Carbon Tetrachloride | 1.9 µg/L 38% of the EPA limit 5 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Combined Radium (-226 And -228) | 1.5 pCi/L 30% of the EPA limit 5 pCi/L Main supplier: CITY OF MERCEDES · 16,258 people · 2017 | 1/3 | SYR4 |
| Atrazine | 0.1400 µg/L 4.7% of the EPA limit 3 µg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2019 | 1/3 | SYR4 |
| Lead | 0.0037 mg/L 25% of the EPA limit 0.0150 mg/L Main supplier: CITY OF MERCEDES · 16,258 people · 2025
Highest in the city: 0.0156 mg/L — LLANO GRANDE LAKE PARK WEST · 300 people · 2025 | 3/3 | LCR |
| Pfhxa | 0.0033 µg/L No EPA limit set Main supplier: CITY OF MERCEDES · 16,258 people · 2024 | 1/3 | UCMR-5 |
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 Mercedes
| Supplier | Population served |
|---|---|
| CITY OF MERCEDES | 16,258 |
| LLANO GRANDE LAKE PARK EAST | 1,300 |
| LLANO GRANDE LAKE PARK WEST | 300 |
Frequently asked questions about Mercedes tap water
Is Mercedes tap water safe to drink?
EPA testing detected 26 contaminants in the water serving Mercedes. 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 Mercedes?
3 public water suppliers report drinking-water monitoring for Mercedes, Texas to the EPA. Each is listed above with its population served.
What contaminants are in Mercedes's water?
The contaminants EPA monitoring detected in Mercedes include Copper, Fluoride, Nitrate, Cyanide, TTHM. 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.