What was found in Ukiah'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 | 2735 µg/L 27% of the EPA limit 10000 µg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2019 | 7/9 | SYR4 |
| Nitrate-Nitrite | 2681 µg/L 27% of the EPA limit 10000 µg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2016 | 1/9 | SYR4 |
| Barium | 110 µg/L 5.5% of the EPA limit 2000 µg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 527 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 6/9 | SYR4 |
| Fluoride | 161 µg/L 4% of the EPA limit 4000 µg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 227 µg/L — CALPELLA COUNTY WATER DISTRICT · 548 people · 2019 | 9/9 | SYR4 |
| TTHM | 30.81 µg/L 39% of the EPA limit 80 µg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 85.8835 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 7/9 | SYR4 |
| Chloroform | 21.85 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 75.993 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 6/9 | SYR4 |
| Total Haloacetic Acids (HAA5) | 24.01 µg/L 40% of the EPA limit 60 µg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 42.285 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 7/9 | SYR4 |
| Dichloroacetic Acid | 11.965 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 24.135 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 6/9 | SYR4 |
| Trichloroacetic Acid | 11.94 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 22.68 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 6/9 | SYR4 |
| Bromodichloromethane | 8.1775 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 9.1475 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 7/9 | SYR4 |
| Monochloroacetic Acid | 6.65 µg/L No EPA limit set Highest in the city: REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 1/9 | SYR4 |
| Dibromochloromethane | 3.7585 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 5.85 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 7/9 | SYR4 |
| Arsenic | 4.7 µg/L 47% of the EPA limit 10 µg/L Highest in the city: RIVER ESTATES MUTUAL WATER COMPANY · 250 people · 2019 | 3/9 | SYR4 |
| Gross Beta Particle Activity | 4 pCi/L No EPA limit set Highest in the city: REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2017 | 1/9 | SYR4 |
| Bromoform | 2.5995 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 3.017 µg/L — HOPLAND PUBLIC UTILITY DISTRICT · 1,076 people · 2019 | 5/9 | SYR4 |
| Dibromoacetic Acid | 2.105 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 2.7 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 6/9 | SYR4 |
| Monobromoacetic Acid | 1.8 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2019
Highest in the city: 1.86 µg/L — REDWOOD VALLEY COUNTY WATER DISTRICT · 5,200 people · 2019 | 2/9 | SYR4 |
| Toluene | 0.7100 µg/L 0.1% of the EPA limit 1000 µg/L Highest in the city: MILLVIEW COUNTY WATER DISTRICT · 5,500 people · 2018 | 1/9 | SYR4 |
| Asbestos | 0.2000 MFL 2.9% of the EPA limit 7 MFL Main supplier: UKIAH, CITY OF · 16,607 people · 2019 | 1/9 | SYR4 |
| 6:2 Fts | 0.0178 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| Pfba | 0.0092 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| PFOS | 0.0074 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| PFHXS | 0.0073 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| PFOA | 0.0069 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| PFBS | 0.0062 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| Pfpea | 0.0051 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| Pfhxa | 0.0044 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| Pfhpa | 0.0033 µg/L No EPA limit set Main supplier: UKIAH, CITY OF · 16,607 people · 2024 | 1/9 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: UKIAH, CITY OF · 16,607 people · 2026 | 9/9 | 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 Ukiah
| Supplier | Population served |
|---|---|
| UKIAH, CITY OF | 16,607 |
| MILLVIEW COUNTY WATER DISTRICT | 5,500 |
| REDWOOD VALLEY COUNTY WATER DISTRICT | 5,200 |
| WILLOW COUNTY WATER DISTRICT | 3,797 |
| HOPLAND PUBLIC UTILITY DISTRICT | 1,076 |
| CALPELLA COUNTY WATER DISTRICT | 548 |
| CITY OF 10,000 BUDDHAS | 400 |
| RIVER ESTATES MUTUAL WATER COMPANY | 250 |
| COVELO MOBILE HOME PARK | 30 |
Frequently asked questions about Ukiah tap water
Is Ukiah tap water safe to drink?
EPA testing detected 29 contaminants in the water serving Ukiah. 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 Ukiah?
9 public water suppliers report drinking-water monitoring for Ukiah, California to the EPA. Each is listed above with its population served.
What contaminants are in Ukiah's water?
The contaminants EPA monitoring detected in Ukiah include Nitrate, Nitrate-Nitrite, Barium, Fluoride, TTHM. 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.