What was found in ZIP 90503
The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Fluoride | 879.2 µg/L 22% of the EPA limit 4000 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 885.5 µg/L — CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2019 | 2/3 | SYR4 |
| Nitrate | 435 µg/L 4.4% of the EPA limit 10000 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 730 µg/L — CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2019 | 2/3 | SYR4 |
| Nitrate-Nitrite | 730 µg/L 7.3% of the EPA limit 10000 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2018 | 1/3 | SYR4 |
| Barium | 172 µg/L 8.6% of the EPA limit 2000 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 247.5 µg/L — CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2018 | 2/3 | SYR4 |
| TTHM | 77.28 µg/L 97% of the EPA limit 80 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Lithium | 64.7 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2025 | 3/3 | UCMR-5 |
| Copper | 15.114 µg/L 1.2% of the EPA limit 1300 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 42.6548 µg/L — CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2018 | 2/3 | SYR4 |
| Bromoform | 8.73 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 42.08 µg/L — TORRANCE-CITY, WATER DEPT. · 106,183 people · 2019 | 3/3 | SYR4 |
| Chloroform | 41.354 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Selenium | 39.4 µg/L 79% of the EPA limit 50 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 2/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 29 µg/L 48% of the EPA limit 60 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Dibromochloromethane | 19.96 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 19.73 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Combined Uranium | 17.135 µg/L 57% of the EPA limit 30 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2018 | 1/3 | SYR4 |
| Monochloroacetic Acid | 15.185 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 15 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 12 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 3/3 | SYR4 |
| Gross Beta Particle Activity | 10 pCi/L No EPA limit set Highest in the ZIP: CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2018 | 1/3 | SYR4 |
| Dibromoacetic Acid | 7.8 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 8.49 µg/L — TORRANCE-CITY, WATER DEPT. · 106,183 people · 2019 | 3/3 | SYR4 |
| Trichloroethylene | 3.8145 µg/L 76% of the EPA limit 5 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 1/3 | SYR4 |
| Arsenic | 3.604 µg/L 36% of the EPA limit 10 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 2/3 | SYR4 |
| Dichloromethane | 3.455 µg/L 69% of the EPA limit 5 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 1.83 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 2.115 µg/L — TORRANCE-CITY, WATER DEPT. · 106,183 people · 2019 | 3/3 | SYR4 |
| Chromium | 1.663 µg/L 1.7% of the EPA limit 100 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 2/3 | SYR4 |
| Lead | 0.0260 µg/L 0.2% of the EPA limit 15 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019
Highest in the ZIP: 0.7370 µg/L — CALIFORNIA WATER SERVICE CO. - HERM/REDO · 96,853 people · 2018 | 2/3 | SYR4 |
| Antimony, Total | 0.0590 µg/L 1% of the EPA limit 6 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 2/3 | SYR4 |
| Cadmium | 0.0140 µg/L 0.3% of the EPA limit 5 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 2/3 | SYR4 |
| PFHXS | 0.0035 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2025 | 1/3 | UCMR-5 |
| Beryllium, Total | 0.0030 µg/L 0.1% of the EPA limit 4 µg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2019 | 2/3 | SYR4 |
| Lead | 0.0018 mg/L 12% of the EPA limit 0.0150 mg/L Main supplier: CALIFORNIA WATER SERVICE CO. - DOMINGUEZ · 143,996 people · 2023 | 3/3 | 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.
Water suppliers serving ZIP 90503
| Supplier | State | Population served |
|---|---|---|
| CALIFORNIA WATER SERVICE CO. - DOMINGUEZ | CA | 143,996 |
| TORRANCE-CITY, WATER DEPT. | CA | 106,183 |
| CALIFORNIA WATER SERVICE CO. - HERM/REDO | CA | 96,853 |
Frequently asked questions about ZIP 90503 tap water
Is the tap water in ZIP 90503 safe to drink?
EPA testing detected 30 contaminants across the water suppliers serving ZIP 90503. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.
Which water suppliers serve ZIP 90503?
3 public water suppliers report EPA drinking-water monitoring for ZIP 90503. Each is listed above with its population served.
What contaminants are in ZIP 90503's water?
EPA monitoring detected Fluoride, Nitrate, Nitrate-Nitrite, Barium, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.