What was found in ZIP 91790
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 | 235059.99999999919 µg/L 2351% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 2/3 | SYR4 |
| Nitrate | 11752 µg/L 118% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 12000 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Fluoride | 696.9999999999999 µg/L 17% of the EPA limit 4000 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 3/3 | SYR4 |
| Barium | 207.00000000000003 µg/L 10% of the EPA limit 2000 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 221.99999999999994 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Tetrachloroethylene | 110 µg/L 2200% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 3/3 | SYR4 |
| TTHM | 10 µg/L 13% of the EPA limit 80 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 68.39999999999998 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Trichloroethylene | 61 µg/L 1220% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 2/3 | SYR4 |
| Lithium | 54 µg/L No EPA limit set Highest in the ZIP: SUBURBAN WATER SYSTEMS-SAN JOSE · 168,843 people · 2025 | 1/3 | UCMR-5 |
| Chloroform | 1.8 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 29 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Dibromochloromethane | 4.429999999999999 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 25.899999999999977 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Bromoform | 4.6 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 21.5 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 1.9100000000000001 µg/L 3.2% of the EPA limit 60 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 21.349999999999994 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 2.4 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 18 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Chromium | 16.7 µg/L 17% of the EPA limit 100 µg/L Highest in the ZIP: SUBURBAN WATER SYSTEMS-SAN JOSE · 168,843 people · 2019 | 1/3 | SYR4 |
| Arsenic | 3.005 µg/L 30% of the EPA limit 10 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 16 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Combined Uranium | 13.737799999999998 µg/L 46% of the EPA limit 30 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 3/3 | SYR4 |
| 1,1-Dichloroethylene | 12 µg/L 171% of the EPA limit, at the 95th percentile of samples — 7 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 2/3 | SYR4 |
| Dichloroacetic Acid | 11.149999999999977 µg/L No EPA limit set Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 9.734999999999996 µg/L No EPA limit set Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 1.9100000000000001 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019
Highest in the ZIP: 8.225 µg/L — AZUSA LIGHT AND WATER · 110,044 people · 2019 | 3/3 | SYR4 |
| Carbon Tetrachloride | 7.8299999999999725 µg/L 157% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 2/3 | SYR4 |
| Gross Beta Particle Activity | 5.645 pCi/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2018 | 1/3 | SYR4 |
| trans-1,2-Dichloroethylene | 5.325 µg/L 5.3% of the EPA limit 100 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 2/3 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 5.1 µg/L 85% of the EPA limit 6 µg/L Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2019 | 1/3 | SYR4 |
| Selenium | 5 µg/L 10% of the EPA limit 50 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| cis-1,2-Dichloroethylene | 3.8 µg/L 5.4% of the EPA limit 70 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 2/3 | SYR4 |
| 1,1,2-Trichloroethane | 3.775 µg/L 76% of the EPA limit 5 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| Monochloroacetic Acid | 3 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| 1,2-Dichloroethane | 2.3 µg/L 46% of the EPA limit 5 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 1.58 µg/L No EPA limit set Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2019 | 1/3 | SYR4 |
| Chlorobenzene | 1.3289999999999997 µg/L 1.3% of the EPA limit 100 µg/L Highest in the ZIP: SUBURBAN WATER SYSTEMS-SAN JOSE · 168,843 people · 2019 | 1/3 | SYR4 |
| Pentachlorophenol | 0.8470 µg/L 85% of the EPA limit 1 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| Toluene | 0.5200 µg/L 0.1% of the EPA limit 1000 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| Nitrite | 0.4700 µg/L 0% of the EPA limit 1000 µg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2019 | 1/3 | SYR4 |
| Pfba | 0.0100 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2025 | 2/3 | UCMR-5 |
| PFOA | 0.0077 µg/L No EPA limit set Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2024 | 1/3 | UCMR-5 |
| PFOS | 0.0058 µg/L No EPA limit set Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2024 | 1/3 | UCMR-5 |
| Pfpea | 0.0056 µg/L No EPA limit set Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 people · 2025 | 2/3 | UCMR-5 |
| PFBS | 0.0036 µg/L No EPA limit set Highest in the ZIP: SUBURBAN WATER SYSTEMS-SAN JOSE · 168,843 people · 2025 | 1/3 | UCMR-5 |
| Pfhxa | 0.0035 µg/L No EPA limit set Highest in the ZIP: AZUSA LIGHT AND WATER · 110,044 people · 2024 | 2/3 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: SAN GABRIEL VALLEY WATER CO.-EL MONTE · 248,000 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 91790
| Supplier | State | Population served |
|---|---|---|
| SAN GABRIEL VALLEY WATER CO.-EL MONTE | CA | 248,000 |
| SUBURBAN WATER SYSTEMS-SAN JOSE | CA | 168,843 |
| AZUSA LIGHT AND WATER | CA | 110,044 |
Frequently asked questions about ZIP 91790 tap water
Is the tap water in ZIP 91790 safe to drink?
EPA testing detected 41 contaminants across the water suppliers serving ZIP 91790. 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 91790?
3 public water suppliers report EPA drinking-water monitoring for ZIP 91790. Each is listed above with its population served.
What contaminants are in ZIP 91790's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Barium, Tetrachloroethylene, and others across this ZIP's suppliers. The full list with levels and sources is above.