How does Water and Wastewater Treatment Plant and System Operators salary grow from entry-level to senior in Illinois? State salary progression based on 2024 BLS data.
144% career growth potentialData: BLS OEWS 2024 • Illinois salary data • Updated 2026-04-06
The salary range for Water and Wastewater Treatment Plant and System Operators in Illinois spans from $39,760 at entry-level to $97,130 at senior level — a difference of $57,370 per year.
Senior Water and Wastewater Treatment Plant and System Operatorss in Illinois earn $57,370 more per year than entry-level professionals.
Complete percentile breakdown showing how Water and Wastewater Treatment Plant and System Operators salary increases with experience in Illinois, from entry-level (10th percentile) to senior (90th percentile).
| Experience Level | Percentile | Annual Salary | Monthly | Hourly |
|---|---|---|---|---|
| Entry-Level | P10 | $39,760 | $3,313 | $19.12 |
| Early Career | P25 | $52,410 | $4,368 | $25.20 |
| Mid-Career | Median | $69,070 | $5,756 | $33.21 |
| Experienced | P75 | $79,580 | $6,632 | $38.26 |
| Senior / Expert | P90 | $97,130 | $8,094 | $46.70 |
Water and Wastewater Treatment Plant and System Operators in Illinois shows strong salary progression over a career. Entry-level professionals start around $39,760, while senior-level professionals earn $97,130 — a 144% increase. The biggest salary jump typically occurs between mid-career ($69,070) and experienced level ($79,580), suggesting that specialization and leadership responsibilities are the key drivers of higher pay.
Where does Illinois rank for Water and Wastewater Treatment Plant and System Operators senior-level salaries? Compare Illinois's P90 pay to other top-paying states.
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Entry-level Water and Wastewater Treatment Plant and System Operatorss (10th percentile) earn approximately $39,760 per year, or $3,313 per month. Early-career professionals (25th percentile) earn around $52,410. Based on 2024 BLS OEWS data across all U.S. states.
Senior Water and Wastewater Treatment Plant and System Operatorss (90th percentile) earn approximately $97,130 per year. Experienced professionals (75th percentile) earn around $79,580. This represents a career premium of 144% over entry-level pay.
The career salary growth potential for Water and Wastewater Treatment Plant and System Operatorss is 144%. Entry-level professionals start at $39,760, while senior-level can earn up to $97,130 — a difference of $57,370 per year.
The highest-paying state for senior Water and Wastewater Treatment Plant and System Operatorss is Illinois, where 90th-percentile salaries reach $97,130 per year. See the full state-by-state comparison above.
We use BLS Occupational Employment and Wage Statistics (OEWS) 2024 data. The 10th percentile (P10) approximates entry-level pay — the salary that 90% of workers earn more than. The 90th percentile (P90) approximates senior/expert-level pay — only 10% of workers earn above this threshold. National averages are computed across all reporting U.S. states.
Salary percentile data for Illinois from the U.S. Bureau of Labor Statistics (BLS) Occupational Employment and Wage Statistics (OEWS), May 2024. P10 approximates entry-level compensation; P90 approximates senior/expert-level compensation. State averages differ from national averages due to regional variations in cost of living, demand, and workforce composition. Actual salaries vary based on employer, experience, education, certifications, and specific location within Illinois.
Our Methodology · Data Sources · Source: BLS OEWS