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 |
|---|---|---|---|
| TT | Health-based | Resolved | 1994-01-01 |
| TT | Health-based | Resolved | 1992-12-07 |
| TT | Health-based | Resolved | 1992-12-07 |
| MR | Monitoring | Resolved | 1997-04-01 → 1997-06-30 |
| MR | Monitoring | Resolved | 1997-01-01 → 1997-03-31 |
| MR | Monitoring | Archived | 1994-01-01 → 1993-09-23 |
| MR | Monitoring | Archived | 1993-07-01 → 1993-09-23 |
| MR | Monitoring | Resolved | 1992-07-01 → 1992-12-31 |
| MR | Monitoring | Archived | 1992-07-01 → 1993-09-23 |
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Bromodichloromethane | 13.6 µg/L No EPA limit set
worst single sample: 15.4 µg/L | 141/141 | SYR4 | 2012–2019 |
| Chloroform | 26.9 µg/L No EPA limit set
worst single sample: 35.5 µg/L | 141/141 | SYR4 | 2012–2019 |
| Dibromochloromethane | 6.69 µg/L No EPA limit set
worst single sample: 9.2 µg/L | 141/141 | SYR4 | 2012–2019 |
| Dichloroacetic Acid | 11.9 µg/L No EPA limit set
worst single sample: 14.6 µg/L | 141/141 | SYR4 | 2012–2019 |
| TTHM | 46.6 µg/L 58% of the EPA limit 80 µg/L
worst single sample: 55.3 µg/L | 141/141 | SYR4 | 2012–2019 |
| Total Haloacetic Acids (HAA5) | 24.9 µg/L 42% of the EPA limit 60 µg/L
worst single sample: 30 µg/L | 141/141 | SYR4 | 2012–2019 |
| Trichloroacetic Acid | 10.6 µg/L No EPA limit set
worst single sample: 13.7 µg/L | 141/141 | SYR4 | 2012–2019 |
| Monobromoacetic Acid | 1.9105 µg/L No EPA limit set
worst single sample: 3.39 µg/L | 108/141 | SYR4 | 2012–2019 |
| Dibromoacetic Acid | 1.674 µg/L No EPA limit set
worst single sample: 1.75 µg/L | 47/141 | SYR4 | 2012–2019 |
| Lead | 16.23 µg/L 108% of the EPA limit, at the 95th percentile of samples — 15 µg/L
worst single sample: 22.4 µg/L | 35/104 | SYR4 | 2012–2018 |
| Lead | 0.0051 mg/L 34% of the EPA limit 0.0150 mg/L | 23/23 | LCR | 2025 |
| Monochloroacetic Acid | 4.9175 µg/L No EPA limit set
worst single sample: 5.11 µg/L | 12/141 | SYR4 | 2012–2019 |
| Copper | 264 µg/L 20% of the EPA limit 1300 µg/L
worst single sample: 265 µg/L | 11/104 | SYR4 | 2012–2018 |
31 contaminants tested, none detected
Utility contact
Frequently asked questions about Oak Park
Is Oak Park tap water safe to drink?
EPA monitoring detected 13 contaminants in Oak Park'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 Oak Park's water?
EPA monitoring detected Bromodichloromethane, Chloroform, Dibromochloromethane, Dichloroacetic Acid, TTHM, and others. The full list with the level and data source for each is above.
How many people does Oak Park serve?
Oak Park reports serving 54,583 people in Illinois, per its EPA record.
Has Oak Park had any water quality violations?
The EPA has 9 violations on file for Oak Park, of which 3 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.