What was found in ZIP 94066
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 | 7325 µg/L 73% of the EPA limit 10000 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 286420 µg/L — SAN FRANCISCO REGIONAL WATER SYSTEM · 600 people · 2019 | 3/3 | SYR4 |
| Nitrate | 6736 µg/L 67% of the EPA limit 10000 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 21400 µg/L — SAN FRANCISCO REGIONAL WATER SYSTEM · 600 people · 2019 | 3/3 | SYR4 |
| Fluoride | 139 µg/L 3.5% of the EPA limit 4000 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 819.5 µg/L — SAN FRANCISCO REGIONAL WATER SYSTEM · 600 people · 2019 | 3/3 | SYR4 |
| Nitrite | 400 µg/L 40% of the EPA limit 1000 µg/L Highest in the ZIP: SAN FRANCISCO REGIONAL WATER SYSTEM · 600 people · 2019 | 1/3 | SYR4 |
| Barium | 180 µg/L 9% of the EPA limit 2000 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Copper | 52.3142 µg/L 4% of the EPA limit 1300 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| TTHM | 51.34 µg/L 64% of the EPA limit 80 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 3/3 | SYR4 |
| Chloroform | 51.176 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 46 µg/L 77% of the EPA limit 60 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Lithium | 23.6 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2025
Highest in the ZIP: 40 µg/L — CITY OF SAN BRUNO · 42,631 people · 2025 | 2/3 | UCMR-5 |
| Dichloroacetic Acid | 29 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Chromium | 13.7722 µg/L 14% of the EPA limit 100 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 25.78 µg/L — SAN FRANCISCO REGIONAL WATER SYSTEM · 600 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 17 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Arsenic | 9.81355 µg/L 98% of the EPA limit 10 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 4.5755 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 7.255 µg/L — CITY OF SAN BRUNO · 42,631 people · 2019 | 3/3 | SYR4 |
| Dibromochloromethane | 3.098 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 4.1475 µg/L — CITY OF SAN BRUNO · 42,631 people · 2019 | 2/3 | SYR4 |
| Combined Radium (-226 And -228) | 3.8 pCi/L 76% of the EPA limit 5 pCi/L Highest in the ZIP: SAN FRANCISCO REGIONAL WATER SYSTEM · 600 people · 2019 | 1/3 | SYR4 |
| Bromoform | 3.356 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Monochloroacetic Acid | 2.87 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019
Highest in the ZIP: 3.2 µg/L — CITY OF SAN BRUNO · 42,631 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 3.005 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 2/3 | SYR4 |
| Lead | 2.9949 µg/L 20% of the EPA limit 15 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Combined Uranium | 2.0895 µg/L 7% of the EPA limit 30 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Selenium | 1.5479 µg/L 3.1% of the EPA limit 50 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 1.2 µg/L No EPA limit set Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| 1,2-Dichloropropane | 1.015 µg/L 20% of the EPA limit 5 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Toluene | 0.7800 µg/L 0.1% of the EPA limit 1000 µg/L Highest in the ZIP: CITY OF SAN BRUNO · 42,631 people · 2019 | 1/3 | SYR4 |
| Trichloroethylene | 0.7370 µg/L 15% of the EPA limit 5 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Antimony, Total | 0.1208 µg/L 2% of the EPA limit 6 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Thallium, Total | 0.0224 µg/L 1.1% of the EPA limit 2 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Cadmium | 0.0135 µg/L 0.3% of the EPA limit 5 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Mercury | 0.0130 µg/L 0.7% of the EPA limit 2 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Beryllium, Total | 0.0078 µg/L 0.2% of the EPA limit 4 µg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2019 | 1/3 | SYR4 |
| Lead | 0.0041 mg/L 27% of the EPA limit 0.0150 mg/L Main supplier: CALIFORNIA WATER SERVICE-S SAN FRANCISCO · 64,146 people · 2025 | 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 94066
| Supplier | State | Population served |
|---|---|---|
| CALIFORNIA WATER SERVICE-S SAN FRANCISCO | CA | 64,146 |
| CITY OF SAN BRUNO | CA | 42,631 |
| SAN FRANCISCO REGIONAL WATER SYSTEM | CA | 600 |
Frequently asked questions about ZIP 94066 tap water
Is the tap water in ZIP 94066 safe to drink?
EPA testing detected 33 contaminants across the water suppliers serving ZIP 94066. 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 94066?
3 public water suppliers report EPA drinking-water monitoring for ZIP 94066. Each is listed above with its population served.
What contaminants are in ZIP 94066's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Nitrite, Barium, and others across this ZIP's suppliers. The full list with levels and sources is above.