What was found in Los Angeles'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 | 642000 µg/L 6420% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Nitrate | 7210 µg/L 72% of the EPA limit 10000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Fluoride | 807.2 µg/L 20% of the EPA limit 4000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Barium | 186.6 µg/L 9.3% of the EPA limit 2000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Chromium | 171.5 µg/L 172% of the EPA limit, at the 95th percentile of samples — 100 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Lithium | 100 µg/L No EPA limit set Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2024 | 1/1 | UCMR-5 |
| Copper | 79.54 µg/L 6.1% of the EPA limit 1300 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| TTHM | 59.945 µg/L 75% of the EPA limit 80 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 52.59 µg/L 88% of the EPA limit 60 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Lead | 31.9 µg/L 213% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Trichloroethylene | 26.5 µg/L 530% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Combined Uranium | 22.8074 µg/L 76% of the EPA limit 30 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Tetrachloroethylene | 19.6 µg/L 392% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Selenium | 19.44 µg/L 39% of the EPA limit 50 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Bromate | 11.5 µg/L 115% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Arsenic | 10.875 µg/L 109% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Gross Beta Particle Activity | 10.05 pCi/L No EPA limit set Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| 1,1-Dichloroethylene | 9.116 µg/L 130% of the EPA limit, at the 95th percentile of samples — 7 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| cis-1,2-Dichloroethylene | 3.29 µg/L 4.7% of the EPA limit 70 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Carbon Tetrachloride | 2.32 µg/L 46% of the EPA limit 5 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| 1,1,1-Trichloroethane | 1.896 µg/L 0.9% of the EPA limit 200 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Xylenes, Total | 1.89 µg/L 0% of the EPA limit 10000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Combined Radium (-226 And -228) | 1.2135 pCi/L 24% of the EPA limit 5 pCi/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2018 | 1/1 | SYR4 |
| Cadmium | 1.2 µg/L 24% of the EPA limit 5 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| 1,2-Dichloroethane | 0.5758 µg/L 12% of the EPA limit 5 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Toluene | 0.5220 µg/L 0.1% of the EPA limit 1000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Nitrite | 0.0259 µg/L 0% of the EPA limit 1000 µg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2019 | 1/1 | SYR4 |
| Lead | 0.0039 mg/L 26% of the EPA limit 0.0150 mg/L Main supplier: LOS ANGELES-CITY, DEPT. OF WATER & POWER · 3,875,566 people · 2023 | 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 Los Angeles
| Supplier | Population served |
|---|---|
| LOS ANGELES-CITY, DEPT. OF WATER & POWER | 3,875,566 |
Frequently asked questions about Los Angeles tap water
Is Los Angeles tap water safe to drink?
EPA testing detected 28 contaminants in the water serving Los Angeles. 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 Los Angeles?
1 public water supplier report drinking-water monitoring for Los Angeles, California to the EPA. Each is listed above with its population served.
What contaminants are in Los Angeles's water?
The contaminants EPA monitoring detected in Los Angeles include Nitrate-Nitrite, Nitrate, Fluoride, Barium, Chromium. 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.