What was found in ZIP 91780
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 | 15000 µg/L 150% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 772500 µg/L — CAL-AM WATER COMPANY - EAST PASADENA · 9,949 people · 2018 | 4/5 | SYR4 |
| Nitrate | 10353.1 µg/L 104% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 4/5 | SYR4 |
| Fluoride | 990 µg/L 25% of the EPA limit 4000 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 4/5 | SYR4 |
| Copper | 153.3 µg/L 12% of the EPA limit 1300 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 288.5 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2018 | 2/5 | SYR4 |
| TTHM | 24.6 µg/L 31% of the EPA limit 80 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 122.275 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 5/5 | SYR4 |
| Chloroform | 12.88 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 94.645 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 4/5 | SYR4 |
| Lithium | 91.9 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2025 | 1/5 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 20 µg/L 33% of the EPA limit 60 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 62.71 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 5/5 | SYR4 |
| Barium | 50.8 µg/L 2.5% of the EPA limit 2000 µg/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2013 | 1/5 | SYR4 |
| Trichloroacetic Acid | 9.855 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 36.03 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/5 | SYR4 |
| Combined Uranium | 14.2444 µg/L 47% of the EPA limit 30 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 35.164 µg/L — CAL-AM WATER COMPANY - EAST PASADENA · 9,949 people · 2019 | 4/5 | SYR4 |
| Dichloroacetic Acid | 9.95 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 30.355 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/5 | SYR4 |
| Bromodichloromethane | 12.645 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 24.055 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 5/5 | SYR4 |
| Chromium | 18.4 µg/L 18% of the EPA limit 100 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 3/5 | SYR4 |
| Lead | 1 µg/L 6.7% of the EPA limit 15 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 18.392 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2018 | 2/5 | SYR4 |
| Trichloroethylene | 2.8 µg/L 56% of the EPA limit 5 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 14 µg/L — GSWC-SOUTH ARCADIA · 27,072 people · 2019 | 4/5 | SYR4 |
| Dibromochloromethane | 11.46 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 5/5 | SYR4 |
| Monochloroacetic Acid | 3 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 8.368 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 3/5 | SYR4 |
| Bromoform | 4.89 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 7.16 µg/L — CAL-AM WATER COMPANY - EAST PASADENA · 9,949 people · 2019 | 5/5 | SYR4 |
| Tetrachloroethylene | 6.5 µg/L 130% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 4/5 | SYR4 |
| Dibromoacetic Acid | 4.41 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 5/5 | SYR4 |
| Monobromoacetic Acid | 3.6495 µg/L No EPA limit set Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/5 | SYR4 |
| Dichloromethane | 3.32 µg/L 66% of the EPA limit 5 µg/L Highest in the ZIP: GSWC-SOUTH ARCADIA · 27,072 people · 2019 | 1/5 | SYR4 |
| Arsenic | 2.9 µg/L 29% of the EPA limit 10 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 3.2 µg/L — SUNNY SLOPE WATER CO. · 25,252 people · 2018 | 2/5 | SYR4 |
| 1,2-Dichloropropane | 2.77 µg/L 55% of the EPA limit 5 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/5 | SYR4 |
| Gross Beta Particle Activity | 2.054 pCi/L No EPA limit set Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/5 | SYR4 |
| Mercury | 2.01 µg/L 100% of the EPA limit, at the 95th percentile of samples — 2 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/5 | SYR4 |
| Carbon Tetrachloride | 0.8000 µg/L 16% of the EPA limit 5 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019
Highest in the ZIP: 1.8 µg/L — SUNNY SLOPE WATER CO. · 25,252 people · 2019 | 2/5 | SYR4 |
| 1,1-Dichloroethylene | 1.3 µg/L 19% of the EPA limit 7 µg/L Highest in the ZIP: CAL-AM WATER COMPANY - EAST PASADENA · 9,949 people · 2019 | 1/5 | SYR4 |
| Combined Radium (-226 And -228) | 1.095 pCi/L 22% of the EPA limit 5 pCi/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/5 | SYR4 |
| cis-1,2-Dichloroethylene | 1.04 µg/L 1.5% of the EPA limit 70 µg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2019 | 1/5 | SYR4 |
| 2,4-D | 0.9000 µg/L 1.3% of the EPA limit 70 µg/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/5 | SYR4 |
| trans-1,2-Dichloroethylene | 0.5300 µg/L 0.5% of the EPA limit 100 µg/L Highest in the ZIP: CAL-AM WATER COMPANY - EAST PASADENA · 9,949 people · 2019 | 1/5 | SYR4 |
| PFOS | 0.0220 µg/L No EPA limit set Highest in the ZIP: GSWC-SOUTH ARCADIA · 27,072 people · 2024 | 1/5 | UCMR-5 |
| PFHXS | 0.0070 µg/L No EPA limit set Highest in the ZIP: GSWC-SOUTH ARCADIA · 27,072 people · 2024 | 1/5 | UCMR-5 |
| PFOA | 0.0055 µg/L No EPA limit set Highest in the ZIP: GSWC-SOUTH ARCADIA · 27,072 people · 2024 | 1/5 | UCMR-5 |
| Pfba | 0.0053 µg/L No EPA limit set Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2025 | 1/5 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CAL/AM WATER COMPANY - SAN MARINO · 47,995 people · 2023
Highest in the ZIP: 0.0010 mg/L — CAL-AM WATER COMPANY - EAST PASADENA · 9,949 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.
Water suppliers serving ZIP 91780
| Supplier | State | Population served |
|---|---|---|
| CAL/AM WATER COMPANY - SAN MARINO | CA | 47,995 |
| GSWC-SOUTH ARCADIA | CA | 27,072 |
| SUNNY SLOPE WATER CO. | CA | 25,252 |
| CAL-AM WATER COMPANY - EAST PASADENA | CA | 9,949 |
| BRYAN CO. RWS & SWMD #2 | OK | 6,270 |
Frequently asked questions about ZIP 91780 tap water
Is the tap water in ZIP 91780 safe to drink?
EPA testing detected 38 contaminants across the water suppliers serving ZIP 91780. 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 91780?
5 public water suppliers report EPA drinking-water monitoring for ZIP 91780. Each is listed above with its population served.
What contaminants are in ZIP 91780's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Copper, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.