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 | 2005-11-01 → 2005-11-30 |
| MCL | Health-based | Resolved | 2005-11-01 → 2005-11-30 |
| MCL | Health-based | Resolved | 2005-11-01 → 2005-11-30 |
| MCL | Health-based | Resolved | 2005-11-01 → 2005-11-30 |
| MR | Monitoring | Resolved | 2025-09-29 |
| MR | Monitoring | Resolved | 2025-09-29 |
| MR | Monitoring | Resolved | 2024-07-01 |
| MR | Monitoring | Resolved | 2024-07-01 |
| MR | Monitoring | Resolved | 2024-07-01 |
| MR | Monitoring | Resolved | 2024-07-01 |
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Copper | 727.7 µg/L 56% of the EPA limit 1300 µg/L
worst single sample: 5650 µg/L | 60/98 | SYR4 | 2013–2019 |
| Bromodichloromethane | 11.9 µg/L No EPA limit set
worst single sample: 12.7 µg/L | 52/52 | SYR4 | 2013–2019 |
| Chloroform | 84.385 µg/L No EPA limit set
worst single sample: 106 µg/L | 52/52 | SYR4 | 2013–2019 |
| Dichloroacetic Acid | 39.885 µg/L No EPA limit set
worst single sample: 44.9 µg/L | 52/52 | SYR4 | 2013–2019 |
| TTHM | 94.915 µg/L 119% of the EPA limit, at the 95th percentile of samples — 80 µg/L
worst single sample: 117 µg/L | 52/52 | SYR4 | 2013–2019 |
| Total Haloacetic Acids (HAA5) | 69.48 µg/L 116% of the EPA limit, at the 95th percentile of samples — 60 µg/L
worst single sample: 79.1 µg/L | 52/52 | SYR4 | 2013–2019 |
| Trichloroacetic Acid | 28.295 µg/L No EPA limit set
worst single sample: 32.6 µg/L | 52/52 | SYR4 | 2013–2019 |
| Dibromochloromethane | 3.066 µg/L No EPA limit set
worst single sample: 3.32 µg/L | 35/52 | SYR4 | 2013–2019 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 21/21 | LCR | 2025 |
| Monochloroacetic Acid | 6.015 µg/L No EPA limit set
worst single sample: 7.66 µg/L | 15/52 | SYR4 | 2013–2019 |
| Lead | 331.65 µg/L 2211% of the EPA limit, at the 95th percentile of samples — 15 µg/L
worst single sample: 615 µg/L | 11/98 | SYR4 | 2013–2019 |
| Dibromoacetic Acid | 1.734 µg/L No EPA limit set
worst single sample: 1.8 µg/L | 4/52 | SYR4 | 2013–2019 |
2 contaminants tested, none detected
Utility contact
Frequently asked questions about Wister
Is Wister tap water safe to drink?
EPA monitoring detected 12 contaminants in Wister'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 Wister's water?
EPA monitoring detected Copper, Bromodichloromethane, Chloroform, Dichloroacetic Acid, TTHM, and others. The full list with the level and data source for each is above.
How many people does Wister serve?
Wister reports serving 1,002 people in Oklahoma, per its EPA record.
Has Wister had any water quality violations?
The EPA has 55 violations on file for Wister, of which 4 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.