What was found in ZIP 91764
The highest level seen across the suppliers serving this ZIP, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate-Nitrite | 990000 µg/L 9900% of the EPA limit, in the worst sample — 10000 µg/L | 2/2 | SYR4 |
| Nitrate | 18758 µg/L 188% of the EPA limit, in the worst sample — 10000 µg/L | 2/2 | SYR4 |
| Nitrite | 4900 µg/L 490% of the EPA limit, in the worst sample — 1000 µg/L | 1/2 | SYR4 |
| Fluoride | 810 µg/L 20% of the EPA limit 4000 µg/L | 2/2 | SYR4 |
| TTHM | 160 µg/L 200% of the EPA limit, in the worst sample — 80 µg/L | 2/2 | SYR4 |
| Barium | 140 µg/L 7% of the EPA limit 2000 µg/L | 2/2 | SYR4 |
| Copper | 70 µg/L 5.4% of the EPA limit 1300 µg/L | 1/2 | SYR4 |
| Dibromochloromethane | 60 µg/L No EPA limit set | 2/2 | SYR4 |
| Bromodichloromethane | 50 µg/L No EPA limit set | 2/2 | SYR4 |
| Bromoform | 46 µg/L No EPA limit set | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 43 µg/L 72% of the EPA limit 60 µg/L | 2/2 | SYR4 |
| Chloroform | 37 µg/L No EPA limit set | 2/2 | SYR4 |
| Monochloroacetic Acid | 31 µg/L No EPA limit set | 1/2 | SYR4 |
| Combined Uranium | 14.602 µg/L 49% of the EPA limit 30 µg/L | 1/2 | SYR4 |
| Dibromoacetic Acid | 14.3 µg/L No EPA limit set | 2/2 | SYR4 |
| Trichloroacetic Acid | 14 µg/L No EPA limit set | 2/2 | SYR4 |
| Dichloroacetic Acid | 12 µg/L No EPA limit set | 2/2 | SYR4 |
| Chromium | 8.8 µg/L 8.8% of the EPA limit 100 µg/L | 1/2 | SYR4 |
| Monobromoacetic Acid | 7.8 µg/L No EPA limit set | 2/2 | SYR4 |
| Arsenic | 5.5 µg/L 55% of the EPA limit 10 µg/L | 2/2 | SYR4 |
| 1,2-DIBROMO-3-CHLOROPROPANE | 1.8 µg/L 900% of the EPA limit, in the worst sample — 0.2000 µg/L | 2/2 | SYR4 |
| Picloram | 1.4 µg/L 0.3% of the EPA limit 500 µg/L | 1/2 | SYR4 |
| Dichloromethane | 0.9800 µg/L 20% of the EPA limit 5 µg/L | 1/2 | SYR4 |
| PFOA | 0.0300 µg/L No EPA limit set | 1/2 | UCMR-5 |
| Ethylene Dibromide | 0.0210 µg/L 42% of the EPA limit 0.0500 µg/L | 1/2 | SYR4 |
| Pfhxa | 0.0071 µg/L No EPA limit set | 1/2 | UCMR-5 |
| Pfpea | 0.0067 µg/L No EPA limit set | 1/2 | UCMR-5 |
| Pfba | 0.0064 µg/L No EPA limit set | 1/2 | UCMR-5 |
| PFOS | 0.0052 µg/L No EPA limit set | 1/2 | UCMR-5 |
| PFHXS | 0.0042 µg/L No EPA limit set | 1/2 | UCMR-5 |
| Lead | 0.00060 mg/L 4% of the EPA limit 0.0150 mg/L | 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 single worst sample on
record — over 100% is worth reading, but is not by itself a violation.
Formal violations are listed separately.
Water suppliers serving ZIP 91764
| Supplier | State | Population served |
|---|---|---|
| CUCAMONGA VALLEY WATER DISTRICT | CA | 211,069 |
| ONTARIO MUNICIPAL UTILITIES COMPANY | CA | 185,010 |
Frequently asked questions about ZIP 91764 tap water
Is the tap water in ZIP 91764 safe to drink?
EPA testing detected 31 contaminants across the water suppliers serving ZIP 91764. 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 91764?
2 public water suppliers report EPA drinking-water monitoring for ZIP 91764. Each is listed above with its population served.
What contaminants are in ZIP 91764's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Nitrite, Fluoride, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.