What was found in Montara'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 | 9944 µg/L 99% of the EPA limit 10000 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Nitrate-Nitrite | 9375 µg/L 94% of the EPA limit 10000 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Fluoride | 1700 µg/L 43% of the EPA limit 4000 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Toluene | 120.035 µg/L 12% of the EPA limit 1000 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| TTHM | 51.3 µg/L 64% of the EPA limit 80 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Bromoform | 36.9 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Chromium | 22.95 µg/L 23% of the EPA limit 100 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Dibromochloromethane | 12.9 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Selenium | 8.345 µg/L 17% of the EPA limit 50 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 7.88 µg/L 13% of the EPA limit 60 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Arsenic | 7.7 µg/L 77% of the EPA limit 10 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 7.49 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Chloroform | 5.28 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| cis-1,2-Dichloroethylene | 5 µg/L 7.1% of the EPA limit 70 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Bromodichloromethane | 4.1 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Trichloroacetic Acid | 3.575 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Trichloroethylene | 3.095 µg/L 62% of the EPA limit 5 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Dichloroacetic Acid | 1.75 µg/L No EPA limit set Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| trans-1,2-Dichloroethylene | 1.74 µg/L 1.7% of the EPA limit 100 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Carbon Tetrachloride | 1.1 µg/L 22% of the EPA limit 5 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| 1,2-Dichloropropane | 0.5880 µg/L 12% of the EPA limit 5 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Xylenes, Total | 0.5200 µg/L 0% of the EPA limit 10000 µg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2019 | 1/1 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: MONTARA WATER AND SANITARY DISTRICT · 6,078 people · 2023 | 1/1 | 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 Montara
| Supplier | Population served |
|---|---|
| MONTARA WATER AND SANITARY DISTRICT | 6,078 |
Frequently asked questions about Montara tap water
Is Montara tap water safe to drink?
EPA testing detected 23 contaminants in the water serving Montara. 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 Montara?
1 public water supplier report drinking-water monitoring for Montara, California to the EPA. Each is listed above with its population served.
What contaminants are in Montara's water?
The contaminants EPA monitoring detected in Montara include Nitrate, Nitrate-Nitrite, Fluoride, Toluene, 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.