What was found in Imperial'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 |
|---|---|---|---|
| Fluoride | 375.5 µg/L 9.4% of the EPA limit 4000 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 570 µg/L — IID VILLAGE · 37 people · 2018 | 2/4 | SYR4 |
| Nitrate-Nitrite | 420 µg/L 4.2% of the EPA limit 10000 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 1/4 | SYR4 |
| Nitrate | 410 µg/L 4.1% of the EPA limit 10000 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 1/4 | SYR4 |
| Barium | 129 µg/L 6.5% of the EPA limit 2000 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 2/4 | SYR4 |
| TTHM | 110.71 µg/L 138% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 3/4 | SYR4 |
| Lithium | 61 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2025
Highest in the city: 78.8 µg/L — CENTINELA STATE PRISON · 4,100 people · 2024 | 3/4 | UCMR-5 |
| Chloroform | 43.5 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 3/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 29.15 µg/L 49% of the EPA limit 60 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 40.449999999999996 µg/L — CENTINELA STATE PRISON · 4,100 people · 2019 | 3/4 | SYR4 |
| Bromodichloromethane | 37 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 3/4 | SYR4 |
| Dibromochloromethane | 26.7 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019 | 3/4 | SYR4 |
| Dichloroacetic Acid | 13.869999999999985 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 22.959999999999965 µg/L — CENTINELA STATE PRISON · 4,100 people · 2019 | 3/4 | SYR4 |
| Monochloroacetic Acid | 1.08 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 12.249999999999996 µg/L — CENTINELA STATE PRISON · 4,100 people · 2019 | 3/4 | SYR4 |
| Arsenic | 2.6 µg/L 26% of the EPA limit 10 µg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 11 µg/L — IID VILLAGE · 37 people · 2019 | 2/4 | SYR4 |
| Trichloroacetic Acid | 9.498499999999998 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 10.539999999999997 µg/L — CENTINELA STATE PRISON · 4,100 people · 2019 | 3/4 | SYR4 |
| Monobromoacetic Acid | 6.9099999999999975 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 8.339999999999996 µg/L — CALIPATRIA STATE PRISON · 4,800 people · 2019 | 3/4 | SYR4 |
| Dibromoacetic Acid | 7.4799999999999995 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 8.209999999999997 µg/L — CENTINELA STATE PRISON · 4,100 people · 2019 | 3/4 | SYR4 |
| Bromoform | 4.703999999999995 µg/L No EPA limit set Main supplier: IMPERIAL, CITY OF · 21,591 people · 2019
Highest in the city: 7.534999999999987 µg/L — CALIPATRIA STATE PRISON · 4,800 people · 2019 | 3/4 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: IMPERIAL, CITY OF · 21,591 people · 2025
Highest in the city: 0.0024 mg/L — CALIPATRIA STATE PRISON · 4,800 people · 2023 | 4/4 | 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 Imperial
| Supplier | Population served |
|---|---|
| IMPERIAL, CITY OF | 21,591 |
| CALIPATRIA STATE PRISON | 4,800 |
| CENTINELA STATE PRISON | 4,100 |
| IID VILLAGE | 37 |
Frequently asked questions about Imperial tap water
Is Imperial tap water safe to drink?
EPA testing detected 18 contaminants in the water serving Imperial. 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 Imperial?
4 public water suppliers report drinking-water monitoring for Imperial, California to the EPA. Each is listed above with its population served.
What contaminants are in Imperial's water?
The contaminants EPA monitoring detected in Imperial include Fluoride, Nitrate-Nitrite, Nitrate, Barium, 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.