Water and Wastewater Treatment Plant and System Operators salary in Illinois
Water and Wastewater Treatment Plant and System Operators in Illinois earn a median of $67,810 a year ($32.60 an hour), based on BLS data for 3,500 workers.
Pay ranges from $42,240 for the lowest-paid 10% to $103,690 for the top 10%. That is 13% higher than the national median of $60,020. Illinois ranks 10th of 50 states for water and wastewater treatment plant and system operators pay. There are 0.57 water and wastewater treatment plant and system operators per 1,000 jobs here — the job is less common than nationally (location quotient 0.69). The average (mean) salary is $71,820, above the median because a few high earners pull it up.
Pay range for water and wastewater treatment plant and system operators in Illinois
| Pay level | Yearly | Hourly |
|---|---|---|
| 10th percentile (entry level) | $42,240 | $20.31 |
| 25th percentile | $55,260 | $26.57 |
| Median | $67,810 | $32.60 |
| 75th percentile | $83,140 | $39.97 |
| 90th percentile (top earners) | $103,690 | $49.85 |
| Average (mean) | $71,820 | $34.53 |
Half of water and wastewater treatment plant and system operators earn more than the median and half earn less. Percentiles show the spread: 10% earn less than the 10th percentile, and 10% earn more than the 90th.
Median paycheck, before taxes
| Pay period | Amount |
|---|---|
| Monthly | $5,650.83 |
| Semi-monthly (24 a year) | $2,825.42 |
| Biweekly (26 a year) | $2,608.08 |
| Weekly | $1,304.04 |
| Hourly | $32.60 |
Based on a full-time year of 2,080 hours. Convert any amount with the hourly to salary converter.
Buying a home? On a $67,810 salary, see how much house you can afford in Illinois at today's mortgage rates, or work out a payment with the mortgage calculator.
Water and Wastewater Treatment Plant and System Operators salary in cities in Illinois
| Metro area | Median salary | Workers |
|---|---|---|
| Chicago-Naperville-Elgin, IL-IN | $79,290 | 1,770 |
| Bloomington, IL | $79,220 | 60 |
| Rockford, IL | $77,830 | 90 |
| Davenport-Moline-Rock Island, IA-IL | $63,440 | 220 |
| Decatur, IL | $62,150 | 50 |
| Champaign-Urbana, IL | $61,720 | 90 |
| Peoria, IL | $60,380 | 120 |
| Kankakee, IL | $59,870 | 70 |
| Springfield, IL | $58,990 | 50 |
| St. Louis, MO-IL | $57,850 | 1,220 |
| Paducah, KY-IL | $52,160 | 70 |
| Cape Girardeau, MO-IL | $50,960 | 60 |
Highest-paying states for water and wastewater treatment plant and system operators
| State | Median salary |
|---|---|
| California | $81,770 |
| Nevada | $81,440 |
| Washington | $80,800 |
| Connecticut | $78,820 |
| New Jersey | $78,760 |
| Minnesota | $74,670 |
| Colorado | $74,200 |
| Oregon | $69,720 |
| Massachusetts | $68,550 |
| Illinois | $67,810 |
See Water and Wastewater Treatment Plant and System Operators pay in every state.
Related jobs in Illinois
| Job | Median salary | Hourly |
|---|---|---|
| Stationary Engineers and Boiler Operators | $115,780 | $55.66 |
| Power Plant Operator | $104,440 | $50.21 |
| Petroleum Pump System Operators, Refinery Operators, and Gaugers | $102,890 | $49.47 |
| Gas Plant Operator | $97,810 | $47.03 |
| Nuclear Power Reactor Operator | $123,980 | $59.60 |
| Power Distributors and Dispatchers | $101,470 | $48.79 |
| Plant and System Operators, All Other | $77,780 | $37.39 |
| Chemical Plant and System Operators | $65,710 | $31.59 |
| Miscellaneous Assemblers and Fabricators | $44,140 | $21.22 |
| Inspectors, Testers, Sorters, Samplers, and Weighers | $47,920 | $23.04 |
| First-Line Supervisors of Production and Operating Workers | $75,200 | $36.16 |
| Packaging and Filling Machine Operators and Tenders | $43,150 | $20.75 |
| Machinist | $58,520 | $28.13 |
| Welders, Cutters, Solderers, and Brazers | $51,320 | $24.67 |
Source: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2025 estimates, occupation code 51-8031. Wages include base pay, tips, commissions and shift pay, but not overtime, bonuses or benefits, and exclude the self-employed.
Frequently asked questions
How much does a water and wastewater treatment plant and system operators make in Illinois?
The median salary for water and wastewater treatment plant and system operators in Illinois is $67,810 a year, or $32.60 an hour. Pay ranges from $42,240 for the lowest-paid 10% to $103,690 for the top 10%.
How much do the highest-paid water and wastewater treatment plant and system operators make in Illinois?
The top 10% of water and wastewater treatment plant and system operators in Illinois earn at least $103,690 a year. The top 25% earn $83,140 or more.
What is the starting pay for water and wastewater treatment plant and system operators in Illinois?
Entry-level pay (the 10th percentile) is about $42,240 a year, and a quarter of water and wastewater treatment plant and system operators earn $55,260 or less.
How many water and wastewater treatment plant and system operators work in Illinois?
About 3,500 water and wastewater treatment plant and system operators are employed in Illinois, not counting the self-employed.