What was found in ZIP 94928
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 | 508000 µg/L 5080% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 2/3 | SYR4 |
| Nitrate | 700.27 µg/L 7% of the EPA limit 10000 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019
Highest in the ZIP: 8177.6 µg/L — ROHNERT PARK, CITY OF · 43,821 people · 2019 | 3/3 | SYR4 |
| Fluoride | 950 µg/L 24% of the EPA limit 4000 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 3/3 | SYR4 |
| Nitrite | 400 µg/L 40% of the EPA limit 1000 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 1/3 | SYR4 |
| Barium | 100 µg/L 5% of the EPA limit 2000 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019
Highest in the ZIP: 159.5 µg/L — ROHNERT PARK, CITY OF · 43,821 people · 2019 | 2/3 | SYR4 |
| Copper | 50 µg/L 3.8% of the EPA limit 1300 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019
Highest in the ZIP: 79 µg/L — ROHNERT PARK, CITY OF · 43,821 people · 2019 | 2/3 | SYR4 |
| TTHM | 56.095 µg/L 70% of the EPA limit 80 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 3/3 | SYR4 |
| Chloroform | 41.214 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 41 µg/L 68% of the EPA limit 60 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 3/3 | SYR4 |
| Lithium | 39 µg/L No EPA limit set Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 2/3 | UCMR-5 |
| Dichloroacetic Acid | 24.51 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 15.715 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 13.676 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 3/3 | SYR4 |
| Combined Uranium | 11.3478 µg/L 38% of the EPA limit 30 µg/L Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/3 | SYR4 |
| Chromium | 10 µg/L 10% of the EPA limit 100 µg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 1/3 | SYR4 |
| Arsenic | 8.6 µg/L 86% of the EPA limit 10 µg/L Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 2/3 | SYR4 |
| Lead | 7.325 µg/L 49% of the EPA limit 15 µg/L Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2015 | 1/3 | SYR4 |
| Dibromochloromethane | 5.5 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019
Highest in the ZIP: 5.9425 µg/L — ROHNERT PARK, CITY OF · 43,821 people · 2019 | 3/3 | SYR4 |
| Selenium | 5.1 µg/L 10% of the EPA limit 50 µg/L Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/3 | SYR4 |
| Bromoform | 2.225 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019
Highest in the ZIP: 3.994 µg/L — SONOMA STATE UNIVERSITY · 10,986 people · 2019 | 3/3 | SYR4 |
| Dibromoacetic Acid | 3.74 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 3.45 µg/L No EPA limit set Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 people · 2019 | 1/3 | SYR4 |
| Xylenes, Total | 3.3 µg/L 0% of the EPA limit 10000 µg/L Highest in the ZIP: SONOMA STATE UNIVERSITY · 10,986 people · 2019 | 1/3 | SYR4 |
| Toluene | 1 µg/L 0.1% of the EPA limit 1000 µg/L Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/3 | SYR4 |
| 6:2 Fts | 0.0071 µg/L No EPA limit set Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 1/3 | UCMR-5 |
| PFHXS | 0.0057 µg/L No EPA limit set Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 1/3 | UCMR-5 |
| PFOS | 0.0045 µg/L No EPA limit set Highest in the ZIP: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 1/3 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: MARIN MUNICIPAL WATER DISTRICT · 186,895 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 94928
| Supplier | State | Population served |
|---|---|---|
| MARIN MUNICIPAL WATER DISTRICT | CA | 186,895 |
| ROHNERT PARK, CITY OF | CA | 43,821 |
| SONOMA STATE UNIVERSITY | CA | 10,986 |
Frequently asked questions about ZIP 94928 tap water
Is the tap water in ZIP 94928 safe to drink?
EPA testing detected 28 contaminants across the water suppliers serving ZIP 94928. 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 94928?
3 public water suppliers report EPA drinking-water monitoring for ZIP 94928. Each is listed above with its population served.
What contaminants are in ZIP 94928'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.