What was found in ZIP 94558
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 | 942600 µg/L 9426% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Nitrate | 1900 µg/L 19% of the EPA limit 10000 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Copper | 96 µg/L 7.4% of the EPA limit 1300 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019
Highest in the ZIP: 382.55 µg/L — KOHALA RANCH WATER CO. · 850 people · 2019 | 3/3 | SYR4 |
| Fluoride | 213.4 µg/L 5.3% of the EPA limit 4000 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019
Highest in the ZIP: 278.5 µg/L — CITY OF VALLEJO-LAKES SYSTEM · 2,800 people · 2019 | 2/3 | SYR4 |
| Chlorite | 245 µg/L 25% of the EPA limit 1000 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Lead | 44.28 µg/L 295% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019
Highest in the ZIP: 117.19 µg/L — KOHALA RANCH WATER CO. · 850 people · 2019 | 2/3 | SYR4 |
| TTHM | 99.15 µg/L 124% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 3/3 | SYR4 |
| Chromium | 92.115 µg/L 92% of the EPA limit 100 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Chloroform | 77 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 57.16 µg/L 95% of the EPA limit 60 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Barium | 37.85 µg/L 1.9% of the EPA limit 2000 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Trichloroacetic Acid | 31.68 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 25 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Dichloroacetic Acid | 23 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Bromoform | 1.755 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019
Highest in the ZIP: 16.875 µg/L — KOHALA RANCH WATER CO. · 850 people · 2019 | 2/3 | SYR4 |
| Dibromochloromethane | 12 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Monochloroacetic Acid | 8.36 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Bromate | 5.775 µg/L 58% of the EPA limit 10 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Gross Beta Particle Activity | 1.6255 pCi/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2018
Highest in the ZIP: 5.74 pCi/L — KOHALA RANCH WATER CO. · 850 people · 2019 | 2/3 | SYR4 |
| Arsenic | 4.617 µg/L 46% of the EPA limit 10 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019
Highest in the ZIP: 4.91 µg/L — CITY OF VALLEJO-LAKES SYSTEM · 2,800 people · 2019 | 2/3 | 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 |
| Di(2-ethylhexyl) Phthalate | 3.8 µg/L 63% of the EPA limit 6 µg/L Highest in the ZIP: CITY OF VALLEJO-LAKES SYSTEM · 2,800 people · 2018 | 1/3 | SYR4 |
| Combined Uranium | 2.831 µg/L 9.4% of the EPA limit 30 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 2.355 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Cadmium | 2.245 µg/L 45% of the EPA limit 5 µg/L Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 1.7 µg/L No EPA limit set Main supplier: NAPA, CITY OF · 84,804 people · 2019 | 1/3 | SYR4 |
| Trichloroethylene | 0.9700 µg/L 19% of the EPA limit 5 µg/L Highest in the ZIP: CITY OF VALLEJO-LAKES SYSTEM · 2,800 people · 2019 | 1/3 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: NAPA, CITY OF · 84,804 people · 2024
Highest in the ZIP: 0.0107 mg/L — KOHALA RANCH WATER CO. · 850 people · 2021 | 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 94558
| Supplier | State | Population served |
|---|---|---|
| NAPA, CITY OF | CA | 84,804 |
| CITY OF VALLEJO-LAKES SYSTEM | CA | 2,800 |
| KOHALA RANCH WATER CO. | HI | 850 |
Frequently asked questions about ZIP 94558 tap water
Is the tap water in ZIP 94558 safe to drink?
EPA testing detected 28 contaminants across the water suppliers serving ZIP 94558. 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 94558?
3 public water suppliers report EPA drinking-water monitoring for ZIP 94558. Each is listed above with its population served.
What contaminants are in ZIP 94558's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Copper, Fluoride, Chlorite, and others across this ZIP's suppliers. The full list with levels and sources is above.