What was found in Downey'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 | 3935 µg/L 39% of the EPA limit 10000 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the city: 989500 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 3/5 | SYR4 |
| Fluoride | 400 µg/L 10% of the EPA limit 4000 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the city: 3960 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 4/5 | SYR4 |
| Nitrate | 3700 µg/L 37% of the EPA limit 10000 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 3/5 | SYR4 |
| Barium | 120 µg/L 6% of the EPA limit 2000 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the city: 281 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 3/5 | SYR4 |
| Copper | 200 µg/L 15% of the EPA limit 1300 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 2/5 | SYR4 |
| Lithium | 88.6 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2024 | 3/5 | UCMR-5 |
| TTHM | 52.6 µg/L 66% of the EPA limit 80 µg/L Highest in the city: LIBERTY UTILITIES - MESA CREST · 1,619 people · 2019 | 4/5 | SYR4 |
| Lead | 25 µg/L 167% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 1/5 | SYR4 |
| Total Haloacetic Acids (HAA5) | 21.3 µg/L 36% of the EPA limit 60 µg/L Highest in the city: LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2019 | 4/5 | SYR4 |
| Chloroform | 18.8 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2019 | 4/5 | SYR4 |
| Dibromochloromethane | 17.4 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - MESA CREST · 1,619 people · 2019 | 4/5 | SYR4 |
| Bromodichloromethane | 16.4 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - MESA CREST · 1,619 people · 2019 | 4/5 | SYR4 |
| Combined Uranium | 5.65455 µg/L 19% of the EPA limit 30 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2018
Highest in the city: 14.4828 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 3/5 | SYR4 |
| Antimony, Total | 13 µg/L 217% of the EPA limit, at the 95th percentile of samples — 6 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 1/5 | SYR4 |
| Dichloroacetic Acid | 11.7 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2019 | 4/5 | SYR4 |
| Trichloroacetic Acid | 9.7 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2019 | 4/5 | SYR4 |
| Bromoform | 8.255 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2019 | 4/5 | SYR4 |
| Gross Beta Particle Activity | 7.9 pCi/L No EPA limit set Highest in the city: LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2017 | 2/5 | SYR4 |
| Arsenic | 2.78 µg/L 28% of the EPA limit 10 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the city: 7.5 µg/L — LIBERTY UTILITIES - LYNWOOD · 24,701 people · 2019 | 3/5 | SYR4 |
| Dibromoacetic Acid | 5.68 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - MESA CREST · 1,619 people · 2019 | 4/5 | SYR4 |
| Tetrachloroethylene | 3.155 µg/L 63% of the EPA limit 5 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 3/5 | SYR4 |
| Trichloroethylene | 1.2 µg/L 24% of the EPA limit 5 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the city: 2.85 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 2/5 | SYR4 |
| Monobromoacetic Acid | 2.5 µg/L No EPA limit set Highest in the city: LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 1/5 | SYR4 |
| Dichloromethane | 1.4 µg/L 28% of the EPA limit 5 µg/L Highest in the city: LIBERTY UTILITIES - COMPTON · 26,371 people · 2019 | 3/5 | SYR4 |
| 1,1-Dichloroethylene | 1.16 µg/L 17% of the EPA limit 7 µg/L Highest in the city: LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 1/5 | SYR4 |
| cis-1,2-Dichloroethylene | 0.6560 µg/L 0.9% of the EPA limit 70 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 1/5 | SYR4 |
| trans-1,2-Dichloroethylene | 0.5800 µg/L 0.6% of the EPA limit 100 µg/L Highest in the city: LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2019 | 1/5 | SYR4 |
| PFOS | 0.0440 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025
Highest in the city: 0.0590 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2024 | 3/5 | UCMR-5 |
| Pfpea | 0.0270 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/5 | UCMR-5 |
| Pfhxa | 0.0210 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/5 | UCMR-5 |
| PFOA | 0.0150 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025
Highest in the city: 0.0160 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2024 | 3/5 | UCMR-5 |
| PFHXS | 0.0089 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025
Highest in the city: 0.0110 µg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2024 | 3/5 | UCMR-5 |
| Pfba | 0.0100 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/5 | UCMR-5 |
| PFBS | 0.0089 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/5 | UCMR-5 |
| Pfhpa | 0.0042 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/5 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2023
Highest in the city: 0.0019 mg/L — LIBERTY UTILITIES - BELLFLOWER-NORWALK · 72,624 people · 2025 | 5/5 | 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 Downey
| Supplier | Population served |
|---|---|
| DOWNEY - CITY, WATER DEPT. | 110,556 |
| LIBERTY UTILITIES - BELLFLOWER-NORWALK | 72,624 |
| LIBERTY UTILITIES - COMPTON | 26,371 |
| LIBERTY UTILITIES - LYNWOOD | 24,701 |
| LIBERTY UTILITIES - MESA CREST | 1,619 |
Frequently asked questions about Downey tap water
Is Downey tap water safe to drink?
EPA testing detected 36 contaminants in the water serving Downey. 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 Downey?
5 public water suppliers report drinking-water monitoring for Downey, California to the EPA. Each is listed above with its population served.
What contaminants are in Downey's water?
The contaminants EPA monitoring detected in Downey include Nitrate-Nitrite, Fluoride, Nitrate, Barium, Copper. 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.