What was found in Rohnert Park's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 8177.6 µg/L 82% of the EPA limit 10000 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 5/5 | SYR4 |
| Nitrate-Nitrite | 6460 µg/L 65% of the EPA limit 10000 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/5 | SYR4 |
| Fluoride | 158.5 µg/L 4% of the EPA limit 4000 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 319.5 µg/L — TERRACE VIEW WATER SYSTEM · 60 people · 2017 | 5/5 | SYR4 |
| Barium | 159.5 µg/L 8% of the EPA limit 2000 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 180 µg/L — ROLLING OAKS ROAD ASSOCIATION · 25 people · 2018 | 2/5 | SYR4 |
| Copper | 79 µg/L 6.1% of the EPA limit 1300 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/5 | SYR4 |
| Lithium | 39 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 2/5 | UCMR-5 |
| TTHM | 24 µg/L 30% of the EPA limit 80 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 28.45 µg/L — GRATON MUTUAL WATER SYSTEM · 50 people · 2017 | 5/5 | SYR4 |
| Arsenic | 8.6 µg/L 86% of the EPA limit 10 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 12.815 µg/L — TERRACE VIEW WATER SYSTEM · 60 people · 2017 | 4/5 | SYR4 |
| Combined Uranium | 11.3478 µg/L 38% of the EPA limit 30 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/5 | SYR4 |
| Chloroform | 11.25 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 5/5 | SYR4 |
| Total Haloacetic Acids (HAA5) | 11.095 µg/L 18% of the EPA limit 60 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 5/5 | SYR4 |
| Bromodichloromethane | 8 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 10.62 µg/L — GRATON MUTUAL WATER SYSTEM · 50 people · 2017 | 5/5 | SYR4 |
| Dibromochloromethane | 5.9425 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 9.825 µg/L — GRATON MUTUAL WATER SYSTEM · 50 people · 2017 | 5/5 | SYR4 |
| Lead | 7.325 µg/L 49% of the EPA limit 15 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2015 | 1/5 | SYR4 |
| Trichloroacetic Acid | 5.84 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 3/5 | SYR4 |
| Bromoform | 2.82 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 5.785 µg/L — GRATON MUTUAL WATER SYSTEM · 50 people · 2017 | 3/5 | SYR4 |
| Dichloroacetic Acid | 5.285 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 3/5 | SYR4 |
| Selenium | 5.1 µg/L 10% of the EPA limit 50 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/5 | SYR4 |
| Dibromoacetic Acid | 2.44 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019
Highest in the city: 4.0905 µg/L — GRATON MUTUAL WATER SYSTEM · 50 people · 2017 | 3/5 | SYR4 |
| Xylenes, Total | 3.3 µg/L 0% of the EPA limit 10000 µg/L Highest in the city: SONOMA STATE UNIVERSITY · 10,986 people · 2019 | 1/5 | SYR4 |
| Monochloroacetic Acid | 2.2 µg/L No EPA limit set Highest in the city: ROLLING OAKS ROAD ASSOCIATION · 25 people · 2018 | 1/5 | SYR4 |
| Toluene | 1 µg/L 0.1% of the EPA limit 1000 µg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2019 | 1/5 | SYR4 |
| 6:2 Fts | 0.0071 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 1/5 | UCMR-5 |
| PFHXS | 0.0057 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 1/5 | UCMR-5 |
| PFOS | 0.0045 µg/L No EPA limit set Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2024 | 1/5 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: ROHNERT PARK, CITY OF · 43,821 people · 2025 | 5/5 | 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.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Rohnert Park
| Supplier | Population served |
|---|---|
| ROHNERT PARK, CITY OF | 43,821 |
| SONOMA STATE UNIVERSITY | 10,986 |
| TERRACE VIEW WATER SYSTEM | 60 |
| GRATON MUTUAL WATER SYSTEM | 50 |
| ROLLING OAKS ROAD ASSOCIATION | 25 |
Frequently asked questions about Rohnert Park tap water
Is Rohnert Park tap water safe to drink?
EPA testing detected 26 contaminants in the water serving Rohnert Park. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Rohnert Park?
5 public water suppliers report drinking-water monitoring for Rohnert Park, California to the EPA. Each is listed above with its population served.
What contaminants are in Rohnert Park's water?
The contaminants EPA monitoring detected in Rohnert Park include Nitrate, Nitrate-Nitrite, Fluoride, Barium, Copper. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.