What was found in ZIP 91803
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-Nitrite | 12200 µg/L 122% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019
Highest in the ZIP: 15000 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 2/2 | SYR4 |
| Nitrate | 12000 µg/L 120% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Fluoride | 880 µg/L 22% of the EPA limit 4000 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019
Highest in the ZIP: 990 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 2/2 | SYR4 |
| Copper | 153.3 µg/L 12% of the EPA limit 1300 µg/L Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| Lithium | 58 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2024
Highest in the ZIP: 91.9 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2025 | 2/2 | UCMR-5 |
| TTHM | 64.25 µg/L 80% of the EPA limit 80 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| cis-1,2-Dichloroethylene | 26 µg/L 37% of the EPA limit 70 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Chloroform | 24.3 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 23 µg/L 38% of the EPA limit 60 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Trichloroethylene | 22 µg/L 440% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 20.3 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 19.3 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Chromium | 18.4 µg/L 18% of the EPA limit 100 µg/L Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| Combined Uranium | 10.9664 µg/L 37% of the EPA limit 30 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2018
Highest in the ZIP: 14.2444 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 12 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Trichloroacetic Acid | 7.44 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019
Highest in the ZIP: 9.855 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 2/2 | SYR4 |
| Bromoform | 6.94 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Tetrachloroethylene | 3.135 µg/L 63% of the EPA limit 5 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019
Highest in the ZIP: 6.5 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 5.395 µg/L No EPA limit set Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 3 µg/L No EPA limit set Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| Arsenic | 2.9 µg/L 29% of the EPA limit 10 µg/L Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| 1,2-Dichloropropane | 2.77 µg/L 55% of the EPA limit 5 µg/L Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| Mercury | 2.01 µg/L 100% of the EPA limit, at the 95th percentile of samples — 2 µg/L Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| Lead | 1 µg/L 6.7% of the EPA limit 15 µg/L Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/2 | SYR4 |
| Carbon Tetrachloride | 0.5200 µg/L 10% of the EPA limit 5 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019
Highest in the ZIP: 0.8000 µg/L — CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 2/2 | SYR4 |
| trans-1,2-Dichloroethylene | 0.7800 µg/L 0.8% of the EPA limit 100 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 1/2 | SYR4 |
| 1,1-Dichloroethylene | 0.7160 µg/L 10% of the EPA limit 7 µg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2019 | 1/2 | SYR4 |
| Pfba | 0.0053 µg/L No EPA limit set Highest in the ZIP: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2025 | 1/2 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CITY OF ALHAMBRA · 79,776 people · 2024 | 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 91803
| Supplier | State | Population served |
|---|---|---|
| CITY OF ALHAMBRA | CA | 79,776 |
| CAL/AM WATER COMPANY - SAN MARINO | CA | 47,995 |
Frequently asked questions about ZIP 91803 tap water
Is the tap water in ZIP 91803 safe to drink?
EPA testing detected 29 contaminants across the water suppliers serving ZIP 91803. 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 91803?
2 public water suppliers report EPA drinking-water monitoring for ZIP 91803. Each is listed above with its population served.
What contaminants are in ZIP 91803's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Copper, Lithium, and others across this ZIP's suppliers. The full list with levels and sources is above.