What was found in ZIP 94022
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 | 8440.5604 µg/L 84% of the EPA limit 10000 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 3/4 | SYR4 |
| Nitrate-Nitrite | 7100 µg/L 71% of the EPA limit 10000 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 2/4 | SYR4 |
| Barium | 183.92244999999997 µg/L 9.2% of the EPA limit 2000 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 614 µg/L — CITY OF PALO ALTO · 67,231 people · 2018 | 3/4 | SYR4 |
| Fluoride | 207.5 µg/L 5.2% of the EPA limit 4000 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 377.5 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 3/4 | SYR4 |
| TTHM | 60.51 µg/L 76% of the EPA limit 80 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 71.02 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 4/4 | SYR4 |
| Chloroform | 16.064999999999976 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 61.333999999999996 µg/L — PURISSIMA HILLS WATER DISTRICT · 6,245 people · 2019 | 4/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 29.25 µg/L 49% of the EPA limit 60 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 54 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 4/4 | SYR4 |
| Bromoform | 15.95 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 33.73199999999997 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 3/4 | SYR4 |
| Dichloroacetic Acid | 12 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 32 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 4/4 | SYR4 |
| Copper | 3.741399999999999 µg/L 0.3% of the EPA limit 1300 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 27.98395 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 2/4 | SYR4 |
| Dibromochloromethane | 25 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 4/4 | SYR4 |
| Trichloroacetic Acid | 11 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 24.904999999999994 µg/L — PURISSIMA HILLS WATER DISTRICT · 6,245 people · 2019 | 4/4 | SYR4 |
| Bromodichloromethane | 19.557999999999996 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 4/4 | SYR4 |
| Dibromoacetic Acid | 11 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 3/4 | SYR4 |
| Chromium | 10.35245 µg/L 10% of the EPA limit 100 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 2/4 | SYR4 |
| Combined Uranium | 1.980806 µg/L 6.6% of the EPA limit 30 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 5.4235999999999995 µg/L — CITY OF PALO ALTO · 67,231 people · 2016 | 3/4 | SYR4 |
| Monochloroacetic Acid | 3.82 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 5.3500000000000005 µg/L — CITY OF PALO ALTO · 67,231 people · 2019 | 4/4 | SYR4 |
| Monobromoacetic Acid | 1.564999999999999 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 4.059999999999999 µg/L — CITY OF PALO ALTO · 67,231 people · 2019 | 3/4 | SYR4 |
| Selenium | 3.9272499999999986 µg/L 7.9% of the EPA limit 50 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 2/4 | SYR4 |
| Arsenic | 0.5176 µg/L 5.2% of the EPA limit 10 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 2.1 µg/L — CITY OF PALO ALTO · 67,231 people · 2018 | 3/4 | SYR4 |
| Lead | 0.3208 µg/L 2.1% of the EPA limit 15 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 0.4694 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 2/4 | SYR4 |
| Antimony, Total | 0.0181 µg/L 0.3% of the EPA limit 6 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 0.2215 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 2/4 | SYR4 |
| Cadmium | 0.0125 µg/L 0.2% of the EPA limit 5 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 0.0280 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 2/4 | SYR4 |
| Mercury | 0.0195 µg/L 1% of the EPA limit 2 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 1/4 | SYR4 |
| Beryllium, Total | 0.0020 µg/L 0.1% of the EPA limit 4 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019
Highest in the ZIP: 0.0118 µg/L — CALIFORNIA WATER SERVICE - BEAR GULCH · 61,431 people · 2019 | 2/4 | SYR4 |
| Thallium, Total | 0.0080 µg/L 0.4% of the EPA limit 2 µg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2019 | 1/4 | SYR4 |
| Lead | 0.0015 mg/L 10% of the EPA limit 0.0150 mg/L Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2025
Highest in the ZIP: 0.0060 mg/L — PURISSIMA HILLS WATER DISTRICT · 6,245 people · 2023 | 4/4 | LCR |
| PFHXS | 0.0035 µg/L No EPA limit set Main supplier: CWSC LOS ALTOS SUBURBAN · 69,973 people · 2025 | 1/4 | UCMR-5 |
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 94022
| Supplier | State | Population served |
|---|---|---|
| CWSC LOS ALTOS SUBURBAN | CA | 69,973 |
| CITY OF PALO ALTO | CA | 67,231 |
| CALIFORNIA WATER SERVICE - BEAR GULCH | CA | 61,431 |
| PURISSIMA HILLS WATER DISTRICT | CA | 6,245 |
Frequently asked questions about ZIP 94022 tap water
Is the tap water in ZIP 94022 safe to drink?
EPA testing detected 28 contaminants across the water suppliers serving ZIP 94022. 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 94022?
4 public water suppliers report EPA drinking-water monitoring for ZIP 94022. Each is listed above with its population served.
What contaminants are in ZIP 94022's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Barium, Fluoride, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.