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 |
|---|---|---|---|
| RPT | Monitoring | Unaddressed | 2025-07-02 |
| MR | Monitoring | Resolved | 2024-10-01 |
| MR | Monitoring | Resolved | 2024-10-01 |
| Other | Monitoring | Resolved | 2022-07-01 |
| Other | Monitoring | Resolved | 2022-07-01 |
| MR | Monitoring | Resolved | 2000-01-01 → 2000-12-31 |
| MR | Monitoring | Resolved | 2000-01-01 → 2000-12-31 |
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 25/25 | LCR | 2025 |
| Arsenic | 2.405 µg/L 24% of the EPA limit 10 µg/L
worst single sample: 2.9 µg/L | 12/13 | SYR4 | 2012–2019 |
| Fluoride | 233 µg/L 5.8% of the EPA limit 4000 µg/L
worst single sample: 260 µg/L | 10/13 | SYR4 | 2012–2019 |
| Barium | 50 µg/L 2.5% of the EPA limit 2000 µg/L | 7/13 | SYR4 | 2012–2019 |
| Nitrate-Nitrite | 275 µg/L 2.8% of the EPA limit 10000 µg/L
worst single sample: 300 µg/L | 6/6 | SYR4 | 2017–2019 |
| Nitrate | 500 µg/L 5% of the EPA limit 10000 µg/L | 4/34 | SYR4 | 2012–2019 |
| Bromodichloromethane | 9.6 µg/L No EPA limit set
worst single sample: 10 µg/L | 3/3 | SYR4 | 2015–2019 |
| Chloroform | 53.9 µg/L No EPA limit set
worst single sample: 57 µg/L | 3/3 | SYR4 | 2015–2019 |
| Dibromochloromethane | 2.94 µg/L No EPA limit set
worst single sample: 3 µg/L | 3/3 | SYR4 | 2015–2019 |
| Dichloroacetic Acid | 14.9 µg/L No EPA limit set
worst single sample: 15 µg/L | 3/3 | SYR4 | 2015–2019 |
| Lead | 2.8 µg/L 19% of the EPA limit 15 µg/L
worst single sample: 2.9 µg/L | 3/13 | SYR4 | 2012–2019 |
| TTHM | 66.3 µg/L 83% of the EPA limit 80 µg/L
worst single sample: 70 µg/L | 3/3 | SYR4 | 2015–2019 |
| Total Haloacetic Acids (HAA5) | 31.4 µg/L 52% of the EPA limit 60 µg/L
worst single sample: 32 µg/L | 3/3 | SYR4 | 2015–2019 |
| Trichloroacetic Acid | 12.7 µg/L No EPA limit set
worst single sample: 13 µg/L | 3/3 | SYR4 | 2015–2019 |
| Monochloroacetic Acid | 4.38 µg/L No EPA limit set
worst single sample: 4.5 µg/L | 2/3 | SYR4 | 2015–2019 |
| Bromoform | 3 µg/L No EPA limit set | 1/3 | SYR4 | 2015–2019 |
| Copper | 44 µg/L 3.4% of the EPA limit 1300 µg/L | 1/13 | SYR4 | 2012–2019 |
| Cyanide | 5.4 µg/L 2.7% of the EPA limit 200 µg/L | 1/6 | SYR4 | 2012–2016 |
| Chromium | 2.7 µg/L 2.7% of the EPA limit 100 µg/L | 1/13 | SYR4 | 2012–2019 |
| Combined Uranium | 2.682 µg/L 8.9% of the EPA limit 30 µg/L | 1/1 | SYR4 | 2019 |
37 contaminants tested, none detected
Utility contact
Frequently asked questions about Nps-Ash Mountain
Is Nps-Ash Mountain tap water safe to drink?
EPA monitoring detected 20 contaminants in Nps-Ash Mountain'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 Nps-Ash Mountain's water?
EPA monitoring detected Lead, Arsenic, Fluoride, Barium, Nitrate-Nitrite, and others. The full list with the level and data source for each is above.
How many people does Nps-Ash Mountain serve?
Nps-Ash Mountain reports serving 2,930 people in California, per its EPA record.
Has Nps-Ash Mountain had any water quality violations?
The EPA has 7 violations on file for Nps-Ash Mountain, of which 0 are health-based (a contaminant limit or required treatment was breached) and 1 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.