What was found in ZIP 91778
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 | 7684 µg/L 77% of the EPA limit 10000 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Nitrate-Nitrite | 2900 µg/L 29% of the EPA limit 10000 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2018 | 1/1 | SYR4 |
| Fluoride | 1700 µg/L 43% of the EPA limit 4000 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Copper | 120 µg/L 9.2% of the EPA limit 1300 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2018 | 1/1 | SYR4 |
| Combined Uranium | 15.1384 µg/L 50% of the EPA limit 30 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| TTHM | 8.92 µg/L 11% of the EPA limit 80 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Arsenic | 4.44 µg/L 44% of the EPA limit 10 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Tetrachloroethylene | 4.2 µg/L 84% of the EPA limit 5 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Bromoform | 3.8 µg/L No EPA limit set Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Dibromochloromethane | 3.78 µg/L No EPA limit set Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Bromodichloromethane | 2.07 µg/L No EPA limit set Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Chloroform | 1.5 µg/L No EPA limit set Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 1.43 µg/L No EPA limit set Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 1.43 µg/L 2.4% of the EPA limit 60 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Trichloroethylene | 0.7700 µg/L 15% of the EPA limit 5 µg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2019 | 1/1 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: SAN GABRIEL COUNTY WD · 39,345 people · 2025 | 1/1 | 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 91778
| Supplier | State | Population served |
|---|---|---|
| SAN GABRIEL COUNTY WD | CA | 39,345 |
Frequently asked questions about ZIP 91778 tap water
Is the tap water in ZIP 91778 safe to drink?
EPA testing detected 16 contaminants across the water suppliers serving ZIP 91778. 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 91778?
1 public water supplier report EPA drinking-water monitoring for ZIP 91778. Each is listed above with its population served.
What contaminants are in ZIP 91778's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Fluoride, Copper, Combined Uranium, and others across this ZIP's suppliers. The full list with levels and sources is above.