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 | Resolved | 2017-01-01 → 2017-12-31 |
| MCL | Health-based | Resolved | 2017-01-01 → 2017-12-31 |
| MCL | Health-based | Resolved | 2017-01-01 → 2017-12-31 |
| MCL | Health-based | Resolved | 2016-01-01 → 2016-12-31 |
| MCL | Health-based | Resolved | 2016-01-01 → 2016-12-31 |
| MCL | Health-based | Resolved | 2016-01-01 → 2016-12-31 |
| MCL | Health-based | Resolved | 2012-08-01 → 2012-08-31 |
| MCL | Health-based | Resolved | 2012-08-01 → 2012-08-31 |
| MCL | Health-based | Resolved | 2012-08-01 → 2012-08-31 |
| MCL | Health-based | Resolved | 2012-01-01 → 2012-12-31 |
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Nitrate | 16000 µg/L 160% of the EPA limit, in the worst sample — 10000 µg/L | 218/218 | SYR4 | 2012–2019 |
| Copper | 168 µg/L 13% of the EPA limit 1300 µg/L | 84/90 | SYR4 | 2012–2018 |
| TTHM | 34.7 µg/L 43% of the EPA limit 80 µg/L | 81/115 | SYR4 | 2012–2019 |
| Nitrate-Nitrite | 11400 µg/L 114% of the EPA limit, in the worst sample — 10000 µg/L | 53/53 | SYR4 | 2013–2019 |
| Arsenic | 9.6 µg/L 96% of the EPA limit 10 µg/L | 21/22 | SYR4 | 2012–2018 |
| Chromium | 8.6 µg/L 8.6% of the EPA limit 100 µg/L | 21/21 | SYR4 | 2012–2018 |
| Fluoride | 1700 µg/L 43% of the EPA limit 4000 µg/L | 21/21 | SYR4 | 2012–2018 |
| Barium | 170 µg/L 8.5% of the EPA limit 2000 µg/L | 20/21 | SYR4 | 2012–2018 |
| Total Haloacetic Acids (HAA5) | 4.9 µg/L 8.2% of the EPA limit 60 µg/L | 15/112 | SYR4 | 2012–2019 |
| Lithium | 185 µg/L No EPA limit set | 14/14 | UCMR-5 | 2025 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 10/10 | LCR | 2024 |
| Combined Radium (-226 And -228) | 5.1 pCi/L 102% of the EPA limit, in the worst sample — 5 pCi/L | 6/14 | SYR4 | 2012–2018 |
| Combined Uranium | 10 µg/L 33% of the EPA limit 30 µg/L | 4/4 | SYR4 | 2015–2016 |
| Gross Alpha, Excl. Radon And U | 6.7 pCi/L 45% of the EPA limit 15 pCi/L | 4/4 | SYR4 | 2015–2016 |
| Lead | 7.9 µg/L 53% of the EPA limit 15 µg/L | 3/90 | SYR4 | 2012–2018 |
| Selenium | 8.1 µg/L 16% of the EPA limit 50 µg/L | 2/21 | SYR4 | 2012–2018 |
87 contaminants tested, none detected
Utility contact
Frequently asked questions about Epcor - San Tan
Is Epcor - San Tan tap water safe to drink?
EPA monitoring detected 16 contaminants in Epcor - San Tan'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 Epcor - San Tan's water?
EPA monitoring detected Nitrate, Copper, TTHM, Nitrate-Nitrite, Arsenic, and others. The full list with the level and data source for each is above.
How many people does Epcor - San Tan serve?
Epcor - San Tan reports serving 87,435 people in Arizona, per its EPA record.
Has Epcor - San Tan had any water quality violations?
The EPA has 380 violations on file for Epcor - San Tan, of which 13 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.