What was found in ZIP 94566
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 | 10190 µg/L 102% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 2/3 | SYR4 |
| Nitrate | 4972 µg/L 50% of the EPA limit 10000 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2019
Highest in the ZIP: 8967.2 µg/L — CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 3/3 | SYR4 |
| Copper | 382.55 µg/L 29% of the EPA limit 1300 µg/L Highest in the ZIP: KOHALA RANCH WATER CO. · 850 people · 2019 | 2/3 | SYR4 |
| Barium | 326 µg/L 16% of the EPA limit 2000 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2018
Highest in the ZIP: 340 µg/L — CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 2/3 | SYR4 |
| Fluoride | 160 µg/L 4% of the EPA limit 4000 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2018
Highest in the ZIP: 173.5 µg/L — CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 2/3 | SYR4 |
| Lead | 117.19 µg/L 781% of the EPA limit, at the 95th percentile of samples — 15 µg/L Highest in the ZIP: KOHALA RANCH WATER CO. · 850 people · 2019 | 2/3 | SYR4 |
| Glyphosate | 50 µg/L 7.1% of the EPA limit 700 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2018 | 1/3 | SYR4 |
| TTHM | 45.34 µg/L 57% of the EPA limit 80 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 3/3 | SYR4 |
| Lithium | 16.8 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025
Highest in the ZIP: 25.1 µg/L — CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2024 | 2/3 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 22.4 µg/L 37% of the EPA limit 60 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Bromoform | 22.318 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 3/3 | SYR4 |
| Chloroform | 19.7325 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Dibromochloromethane | 17.832 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Chromium | 17.4951 µg/L 17% of the EPA limit 100 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 7.004 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019
Highest in the ZIP: 14.098 µg/L — CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 2/3 | SYR4 |
| Dichloroacetic Acid | 11.925 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 11.4 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 10.255 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Tetrachloroethylene | 6.322 µg/L 126% of the EPA limit, at the 95th percentile of samples — 5 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
| Gross Beta Particle Activity | 0.5290 pCi/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2018
Highest in the ZIP: 5.74 pCi/L — KOHALA RANCH WATER CO. · 850 people · 2019 | 3/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.4 pCi/L 29% of the EPA limit 15 pCi/L Highest in the ZIP: KOHALA RANCH WATER CO. · 850 people · 2019 | 1/3 | SYR4 |
| Combined Uranium | 2.831 µg/L 9.4% of the EPA limit 30 µg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2018 | 2/3 | SYR4 |
| Monochloroacetic Acid | 2.4 µg/L No EPA limit set Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 1.99 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2019 | 2/3 | SYR4 |
| Arsenic | 1.3638 µg/L 14% of the EPA limit 10 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
| Selenium | 1.0466 µg/L 2.1% of the EPA limit 50 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
| Antimony, Total | 0.0634 µg/L 1.1% of the EPA limit 6 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
| PFOS | 0.0260 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 2/3 | UCMR-5 |
| PFHXS | 0.0220 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 2/3 | UCMR-5 |
| Cadmium | 0.0127 µg/L 0.3% of the EPA limit 5 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CITY OF PLEASANTON · 76,689 people · 2025
Highest in the ZIP: 0.0107 mg/L — KOHALA RANCH WATER CO. · 850 people · 2021 | 3/3 | LCR |
| Pfba | 0.0063 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 1/3 | UCMR-5 |
| PFBS | 0.0061 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 2/3 | UCMR-5 |
| PFOA | 0.0051 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 2/3 | UCMR-5 |
| Pfpes | 0.0043 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 1/3 | UCMR-5 |
| Pfhxa | 0.0041 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 2/3 | UCMR-5 |
| Pfpea | 0.0041 µg/L No EPA limit set Main supplier: CITY OF PLEASANTON · 76,689 people · 2025 | 2/3 | UCMR-5 |
| Beryllium, Total | 0.0040 µg/L 0.1% of the EPA limit 4 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - LIVERMORE · 60,414 people · 2019 | 1/3 | SYR4 |
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 94566
| Supplier | State | Population served |
|---|---|---|
| CITY OF PLEASANTON | CA | 76,689 |
| CALIFORNIA WATER SERVICE - LIVERMORE | CA | 60,414 |
| KOHALA RANCH WATER CO. | HI | 850 |
Frequently asked questions about ZIP 94566 tap water
Is the tap water in ZIP 94566 safe to drink?
EPA testing detected 38 contaminants across the water suppliers serving ZIP 94566. 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 94566?
3 public water suppliers report EPA drinking-water monitoring for ZIP 94566. Each is listed above with its population served.
What contaminants are in ZIP 94566's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Copper, Barium, Fluoride, and others across this ZIP's suppliers. The full list with levels and sources is above.