What was found in Monterey Park'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 | 6175 µg/L 62% of the EPA limit 10000 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Nitrate | 5800 µg/L 58% of the EPA limit 10000 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Fluoride | 908 µg/L 23% of the EPA limit 4000 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Copper | 145.14999999999998 µg/L 11% of the EPA limit 1300 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Tetrachloroethylene | 78.25 µg/L 1565% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Combined Uranium | 16.7625 µg/L 56% of the EPA limit 30 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Arsenic | 15 µg/L 150% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| TTHM | 9.029999999999998 µg/L 11% of the EPA limit 80 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Bromoform | 6.359999999999999 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Dibromochloromethane | 3.064999999999999 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Monochloroacetic Acid | 3.04 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Trichloroethylene | 2.9 µg/L 58% of the EPA limit 5 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Dichloromethane | 2.4400000000000004 µg/L 49% of the EPA limit 5 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 2.4 µg/L 4% of the EPA limit 60 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 2.31 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Bromodichloromethane | 1.46 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| cis-1,2-Dichloroethylene | 1.3 µg/L 1.9% of the EPA limit 70 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Xylenes, Total | 1.2 µg/L 0% of the EPA limit 10000 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| 1,2,4-Trichlorobenzene | 0.6100 µg/L 0.9% of the EPA limit 70 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| 1,1-Dichloroethylene | 0.5300 µg/L 7.6% of the EPA limit 7 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| trans-1,2-Dichloroethylene | 0.2680 µg/L 0.3% of the EPA limit 100 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Chloroform | 0.2260 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Toluene | 0.1000 µg/L 0% of the EPA limit 1000 µg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2019 | 1/1 | SYR4 |
| Pfba | 0.0074 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2025 | 1/1 | UCMR-5 |
| Pfpea | 0.0050 µg/L No EPA limit set Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2025 | 1/1 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: MONTEREY PARK-CITY, WATER DEPT. · 62,183 people · 2024 | 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 Monterey Park
| Supplier | Population served |
|---|---|
| MONTEREY PARK-CITY, WATER DEPT. | 62,183 |
Frequently asked questions about Monterey Park tap water
Is Monterey Park tap water safe to drink?
EPA testing detected 26 contaminants in the water serving Monterey Park. 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 Monterey Park?
1 public water supplier report drinking-water monitoring for Monterey Park, California to the EPA. Each is listed above with its population served.
What contaminants are in Monterey Park's water?
The contaminants EPA monitoring detected in Monterey Park include Nitrate-Nitrite, Nitrate, Fluoride, Copper, Tetrachloroethylene. 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.