Compliance record
Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.
| Violation | Type | Status | Period |
|---|---|---|---|
| MCL | Health-based | Archived | 2025-07-01 → 2025-09-30 |
| MCL | Health-based | Resolved | 2013-04-01 → 2013-04-30 |
| MCL | Health-based | Resolved | 2013-04-01 → 2013-04-30 |
| MCL | Health-based | Resolved | 2011-09-01 → 2011-09-30 |
| MCL | Health-based | Resolved | 2011-09-01 → 2011-09-30 |
| MCL | Health-based | Resolved | 2007-07-01 → 2007-09-30 |
| MCL | Health-based | Resolved | 2007-07-01 → 2007-09-30 |
| MCL | Health-based | Resolved | 2007-04-01 → 2007-06-30 |
| MCL | Health-based | Resolved | 2007-04-01 → 2007-06-30 |
| MCL | Health-based | Resolved | 2003-08-01 → 2003-08-31 |
PFAS detected
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Nitrate | 9718 µg/L 97% of the EPA limit 10000 µg/L
worst single sample: 15368 µg/L | 846/1478 | SYR4 | 2012–2019 |
| Fluoride | 3100 µg/L 78% of the EPA limit 4000 µg/L
worst single sample: 4100 µg/L | 665/686 | SYR4 | 2012–2019 |
| Arsenic | 15 µg/L 150% of the EPA limit, at the 95th percentile of samples — 10 µg/L
worst single sample: 25 µg/L | 305/600 | SYR4 | 2012–2019 |
| TTHM | 49.69 µg/L 62% of the EPA limit 80 µg/L
worst single sample: 88.9 µg/L | 134/143 | SYR4 | 2012–2019 |
| Dibromochloromethane | 13.98 µg/L No EPA limit set
worst single sample: 16.9 µg/L | 129/143 | SYR4 | 2012–2019 |
| Bromoform | 31.04 µg/L No EPA limit set
worst single sample: 69.1 µg/L | 128/143 | SYR4 | 2012–2019 |
| Bromodichloromethane | 5.355 µg/L No EPA limit set
worst single sample: 12.2 µg/L | 90/143 | SYR4 | 2012–2019 |
| Dibromoacetic Acid | 9.18 µg/L No EPA limit set
worst single sample: 10.6 µg/L | 89/148 | SYR4 | 2012–2019 |
| Total Haloacetic Acids (HAA5) | 9.9 µg/L 17% of the EPA limit 60 µg/L
worst single sample: 11.8 µg/L | 89/148 | SYR4 | 2012–2019 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 36/36 | LCR | 2024 |
| Chloroform | 5.115 µg/L No EPA limit set
worst single sample: 7.2 µg/L | 34/143 | SYR4 | 2012–2019 |
| Dichloroacetic Acid | 2.95 µg/L No EPA limit set
worst single sample: 3.9 µg/L | 20/148 | SYR4 | 2012–2019 |
| Benzene | 0.9520 µg/L 19% of the EPA limit 5 µg/L
worst single sample: 0.9700 µg/L | 13/30 | SYR4 | 2012–2018 |
| Combined Uranium | 18.774 µg/L 63% of the EPA limit 30 µg/L
worst single sample: 19.37 µg/L | 9/12 | SYR4 | 2012–2017 |
| Lithium | 35.9 µg/L No EPA limit set | 8/14 | UCMR-5 | 2024 |
| Barium | 168 µg/L 8.4% of the EPA limit 2000 µg/L
worst single sample: 170 µg/L | 3/9 | SYR4 | 2012–2017 |
| Nitrate-Nitrite | 2690 µg/L 27% of the EPA limit 10000 µg/L
worst single sample: 2700 µg/L | 3/6 | SYR4 | 2014–2017 |
| Trichloroacetic Acid | 2.48 µg/L No EPA limit set
worst single sample: 2.6 µg/L | 3/148 | SYR4 | 2012–2019 |
| Monochloroacetic Acid | 4.58 µg/L No EPA limit set
worst single sample: 4.6 µg/L | 2/148 | SYR4 | 2012–2019 |
| Gross Beta Particle Activity | 12 pCi/L No EPA limit set | 1/4 | SYR4 | 2012 |
85 contaminants tested, none detected
Utility contact
Frequently asked questions about Norco, City of
Is Norco, City of tap water safe to drink?
EPA monitoring detected 27 contaminants in Norco, City of's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.
What contaminants were detected in Norco, City of's water?
EPA monitoring detected Nitrate, Fluoride, Arsenic, TTHM, Dibromochloromethane, and others. The full list with the level and data source for each is above.
How many people does Norco, City of serve?
Norco, City of reports serving 25,068 people in California, per its EPA record.
Has Norco, City of had any water quality violations?
The EPA has 143 violations on file for Norco, City of, of which 36 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.
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.