What was found in ZIP 90241
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 |
|---|---|---|---|
| Nitrate | 3700 µg/L 37% of the EPA limit 10000 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the ZIP: 8175 µg/L — GSWC - NORWALK · 43,167 people · 2019 | 2/2 | SYR4 |
| 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 ZIP: 8150 µg/L — GSWC - NORWALK · 43,167 people · 2018 | 2/2 | 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 ZIP: 465 µg/L — GSWC - NORWALK · 43,167 people · 2019 | 2/2 | SYR4 |
| Copper | 200 µg/L 15% of the EPA limit 1300 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019 | 2/2 | 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 ZIP: 156.5 µg/L — GSWC - NORWALK · 43,167 people · 2018 | 2/2 | SYR4 |
| Lithium | 58 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2025 | 1/2 | UCMR-5 |
| Tetrachloroethylene | 3.155 µg/L 63% of the EPA limit 5 µg/L Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2019
Highest in the ZIP: 55.55 µg/L — GSWC - NORWALK · 43,167 people · 2019 | 2/2 | SYR4 |
| TTHM | 54.8 µg/L 69% of the EPA limit 80 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | 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 ZIP: 40.6 µg/L — GSWC - NORWALK · 43,167 people · 2019 | 2/2 | 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 | 1/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 24.9 µg/L 42% of the EPA limit 60 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| Dibromochloromethane | 18 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| Bromodichloromethane | 15.6 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| Chloroform | 14.95 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| 1,1-Dichloroethylene | 14 µg/L 200% of the EPA limit, at the 95th percentile of samples — 7 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| Bromoform | 14 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | 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 | 1/2 | SYR4 |
| Selenium | 12 µg/L 24% of the EPA limit 50 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2018 | 1/2 | SYR4 |
| Dichloroacetic Acid | 11.35 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | 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 ZIP: 9.983 µg/L — GSWC - NORWALK · 43,167 people · 2019 | 2/2 | SYR4 |
| Trichloroacetic Acid | 7.4 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | 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
Highest in the ZIP: 6.4 µg/L — GSWC - NORWALK · 43,167 people · 2019 | 2/2 | SYR4 |
| Chromium | 6.27 µg/L 6.3% of the EPA limit 100 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2018 | 1/2 | SYR4 |
| Dibromoacetic Acid | 5.645 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| Monochloroacetic Acid | 5.15 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | 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 ZIP: 4.2 µg/L — GSWC - NORWALK · 43,167 people · 2018 | 2/2 | SYR4 |
| Monobromoacetic Acid | 2.2 µg/L No EPA limit set Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| 1,2-Dichloroethane | 1.8 µg/L 36% of the EPA limit 5 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| 1,2-Dichloropropane | 0.8040 µg/L 16% of the EPA limit 5 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2019 | 1/2 | SYR4 |
| Mercury | 0.2100 µg/L 11% of the EPA limit 2 µg/L Highest in the ZIP: GSWC - NORWALK · 43,167 people · 2018 | 1/2 | SYR4 |
| PFOS | 0.0440 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 1/2 | UCMR-5 |
| Pfpea | 0.0270 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/2 | UCMR-5 |
| Pfhxa | 0.0210 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/2 | UCMR-5 |
| PFOA | 0.0150 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 1/2 | UCMR-5 |
| Pfba | 0.0100 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 2/2 | UCMR-5 |
| PFBS | 0.0089 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 1/2 | UCMR-5 |
| PFHXS | 0.0089 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 1/2 | UCMR-5 |
| Pfhpa | 0.0042 µg/L No EPA limit set Main supplier: DOWNEY - CITY, WATER DEPT. · 110,556 people · 2025 | 1/2 | 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 | 2/2 | 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 90241
| Supplier | State | Population served |
|---|---|---|
| DOWNEY - CITY, WATER DEPT. | CA | 110,556 |
| GSWC - NORWALK | CA | 43,167 |
Frequently asked questions about ZIP 90241 tap water
Is the tap water in ZIP 90241 safe to drink?
EPA testing detected 39 contaminants across the water suppliers serving ZIP 90241. 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 90241?
2 public water suppliers report EPA drinking-water monitoring for ZIP 90241. Each is listed above with its population served.
What contaminants are in ZIP 90241's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Fluoride, Copper, Barium, and others across this ZIP's suppliers. The full list with levels and sources is above.