The median annual wage for Water and Wastewater Treatment Plant and System Operators in Illinois is $63,790 (May 2024 BLS OES). The mean (average) is $69,250.
Pay spans roughly $45,460 at the 10th percentile to $98,820 at the 90th, so experience and specialisation move this figure a lot. At the median that is about $30.67 per hour. An estimated 3,870 people work as water and wastewater treatment plant and system operators in Illinois.
| Median (annual) | $63,790 |
| Mean (annual) | $69,250 |
| Median (hourly) | $30.67 |
| 10th percentile | $45,460 |
| 90th percentile | $98,820 |
| Employment | 3,870 |
Updated 2026-07-23.
Source: BLS OES May 2024 — bls.gov/oes. Checked 2026-07-23.