Overview
SourcedOperate or control an entire process or system of machines, often through the use of control boards, to transfer or treat water or wastewater.
O*NET definition of Water and Wastewater Treatment Plant and System Operators (SOC 51-8031) · Job Zone 1-2: Very Little to Some Preparation Needed.
Titles employers use
Sources: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics (OEWS), May 2025 — national estimates by ownership; U.S. Department of Labor, Employment and Training Administration (USDOL/ETA), O*NET 31.0 Database; GovJobs Wiki (editorial). Data captured September 30, 2026.
Requirements
Sourced- Education needed to enter
- High school diploma or equivalent
- Related work experience
- None
- On-the-job training
- Long-term on-the-job training
Education workers say the job requires
Share of surveyed workers in Water and Wastewater Treatment Plant and System Operators (SOC 51-8031) naming each level as required to be hired, 24 respondents, O*NET survey August 2025. Each employer sets its own minimum.
Sources: U.S. Bureau of Labor Statistics, Employment Projections 2025–35 — education and training assignments by detailed occupation (Tables 5.3, 5.4); U.S. Department of Labor, Employment and Training Administration (USDOL/ETA), O*NET 31.0 Database. Data captured September 30, 2026.
How to get hired
SourcedWater and wastewater treatment plant and system operators typically need at least a high school diploma or equivalent. They also complete on-the-job training. A state license is usually required; however, entry-level workers often complete their licensing requirements during on-the-job training.
From the BLS Occupational Outlook Handbook profile “Water and Wastewater Treatment Plant and System Operators”, published August 27, 2026 · Read the full profile. National guidance; each employer runs its own hiring process.
Source: U.S. Bureau of Labor Statistics, Occupational Outlook Handbook, 2025–35 edition (XML compilation). Data captured September 30, 2026.
Academy and training
Sourced- SOC 51-8031
- Long-term on-the-job training
- Job zone
- Very Little to Some Preparation Needed
Academy length, curriculum and paid-training policies are set by each employer and state; they are part of the employer collection stage.
Source: U.S. Bureau of Labor Statistics, Employment Projections 2025–35 — education and training assignments by detailed occupation (Tables 5.3, 5.4). Data captured September 30, 2026.
Promotion ladder
EditorialCertification grade: state certification grade drives the class (operator I–IV). Typical structure for a certified operator; titles, steps and timing differ by employer.
- Operator-in-Training
- Grade I
- Grade II
- Grade III
- Grade IV / Chief Operator
Source: GovJobs Wiki (editorial).
Pay
SourcedMedian annual wage by employer type, national, May 2025. Federal includes the U.S. Postal Service; state and local include public schools and hospitals.
| Employer type | Workers | 10th pct. | 25th | Median | 75th | 90th |
|---|---|---|---|---|---|---|
| Federal | 500 | $61,530 | $67,580 | $72,700 | $78,670 | $85,280 |
| State | 1,130 | $45,450 | $55,600 | $73,900 | $87,700 | $103,260 |
| Local | 95,100 | $39,210 | $48,120 | $60,300 | $74,710 | $89,480 |
| All government | 96,730 | $39,290 | $48,190 | $60,450 | $74,960 | $90,130 |
| Private sector | 31,760 | $38,820 | $47,490 | $58,630 | $74,030 | $91,960 |
Source: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics (OEWS), May 2025 — national estimates by ownership. Data captured September 30, 2026.
Schedule
SourcedShare of surveyed workers in the occupation (O*NET work context, August 2025). Shift patterns and differentials depend on the employer.
Source: U.S. Department of Labor, Employment and Training Administration (USDOL/ETA), O*NET 31.0 Database. Data captured September 30, 2026.
Day-to-day work
Sourced- Collect and test water and sewage samples, using test equipment and color analysis standards.4.9
- Operate and adjust controls on equipment to purify and clarify water, process or dispose of sewage, and generate power.4.8
- Record operational data, personnel attendance, or meter and gauge readings on specified forms.4.8
- Add chemicals, such as ammonia, chlorine, or lime, to disinfect and deodorize water and other liquids.4.7
- Inspect equipment or monitor operating conditions, meters, and gauges to determine load requirements and detect malfunctions.4.3
- Direct and coordinate plant workers engaged in routine operations and maintenance activities.4.1
- Clean and maintain tanks, filter beds, and other work areas, using hand tools and power tools.4.0
- Maintain, repair, and lubricate equipment, using hand tools and power tools.3.8
The 8 most important of 8 core tasks for Water and Wastewater Treatment Plant and System Operators, ranked by importance (1–5) in the O*NET survey of August 2025.
Source: U.S. Department of Labor, Employment and Training Administration (USDOL/ETA), O*NET 31.0 Database. Data captured September 30, 2026.
Related jobs
DerivedExams and free practice tests
Sourced| Exam | Administered by | Used in | Type | Official page |
|---|---|---|---|---|
| ABC Standardized Water Treatment Operator Exams Standardized exams provided through ABC Testing; content defined by WPI Need-to-Know Criteria; administered with a Formula/Conversion Table. | Water Professionals International (WPI), ABC Testing | US | certification | Official page |
Each exam is checked against its administrator's official page. Employers choose which exam they use; confirm with the hiring agency.
Source: Exam administrators and hiring authorities (per record), Official exam administrator pages. Data captured September 30, 2026.
Free practice tests
ABC Wastewater Treatment Operator Class II Certification ExamEntrance or licensing exam · free on Open Exam Prep- ABC Wastewater Treatment Operator Class IV Certification ExamEntrance or licensing exam · free on Open Exam Prep
- ABC Water Treatment Operator Class II Certification ExamPractice for a named exam · free on Open Exam Prep
- ABC/WPI Very Small Water System (VSS) Operator Certification ExamEntrance or licensing exam · free on Open Exam Prep
- ABC/WPI Wastewater Treatment Operator Class I Certification ExamEntrance or licensing exam · free on Open Exam Prep
- ABC/WPI Wastewater Treatment Operator Class III Certification ExamEntrance or licensing exam · free on Open Exam Prep
- ABC/WPI Water Treatment Operator Class I Certification ExamPractice for a named exam · free on Open Exam Prep
- ABC/WPI Water Treatment Operator Class III Certification ExamPractice for a named exam · free on Open Exam Prep
- ABC/WPI Water Treatment Operator Class IV Certification ExamPractice for a named exam · free on Open Exam Prep
- Wastewater Treatment Plant Operator Certification ExamEntrance or licensing exam · free on Open Exam Prep
- Water Treatment Plant Operator Certification ExamPractice for a named exam · free on Open Exam Prep
State versions: 51 states. Pick yours:
Source: Open Exam Prep, Open Exam Prep free practice tests. Data captured October 1, 2026. Each link was opened and its exam title checked on the date shown.
By state
SourcedMedian annual wage for Water and Wastewater Treatment Plant and System Operators (SOC 51-8031) in each state, all employers (BLS state estimates do not separate government from private). Highest first.
| State | Workers | 10th pct. | Median | 90th pct. |
|---|---|---|---|---|
| California | 11,630 | $56,030 | $81,770 | $123,380 |
| Nevada | Not published | $56,110 | $81,440 | $101,820 |
| Washington | 2,030 | $57,720 | $80,800 | $106,270 |
| Connecticut | 980 | $60,900 | $78,820 | $98,850 |
| New Jersey | 2,500 | $51,050 | $78,760 | $99,240 |
| Minnesota | 2,290 | $52,130 | $74,670 | $87,250 |
| Colorado | 2,620 | $50,130 | $74,200 | $95,730 |
| Oregon | 1,240 | $50,270 | $69,720 | $87,880 |
| Massachusetts | 2,510 | $50,980 | $68,550 | $91,390 |
| Illinois | 3,500 | $42,240 | $67,810 | $103,690 |
| Hawaii | 610 | $46,900 | $65,560 | $82,680 |
| Delaware | 340 | $48,160 | $64,940 | $84,360 |
| New York | 5,300 | $48,350 | $63,990 | $102,260 |
| Vermont | 320 | $50,820 | $63,640 | $81,100 |
| Wisconsin | 2,230 | $50,340 | $63,550 | $78,790 |
| Pennsylvania | 4,660 | $45,670 | $63,310 | $80,480 |
| Wyoming | 500 | $46,960 | $63,260 | $107,370 |
| New Hampshire | 510 | $49,170 | $62,940 | $81,290 |
| Maryland | 1,770 | $44,990 | $61,870 | $88,970 |
| Maine | 710 | $49,220 | $61,870 | $84,730 |
| Rhode Island | 420 | $49,150 | $61,820 | $84,640 |
| Arizona | 3,950 | $46,690 | $61,340 | $80,040 |
| Utah | 1,900 | $45,710 | $61,290 | $79,860 |
| Nebraska | 740 | $44,620 | $61,220 | $76,250 |
| Iowa | 2,370 | $46,880 | $60,990 | $76,040 |
| North Dakota | 550 | $47,250 | $60,470 | $78,940 |
| Alaska | 750 | $35,200 | $60,160 | $99,840 |
| Virginia | 3,460 | $38,590 | $59,420 | $79,470 |
| Michigan | 3,400 | $46,710 | $59,270 | $75,910 |
| Ohio | 5,870 | $45,350 | $59,170 | $75,200 |
| Florida | 7,440 | $39,630 | $59,030 | $84,280 |
| Montana | 690 | $37,320 | $58,040 | $81,420 |
| Indiana | 3,140 | $40,590 | $53,540 | $75,290 |
| South Dakota | 1,060 | $43,890 | $53,370 | $73,170 |
| Idaho | 1,480 | $40,820 | $52,210 | $74,950 |
| South Carolina | 2,650 | $39,060 | $52,090 | $76,850 |
| Alabama | 2,770 | $35,100 | $51,870 | $79,950 |
| North Carolina | 3,620 | $37,860 | $51,680 | $75,600 |
| Tennessee | 3,140 | $35,430 | $50,670 | $75,540 |
| Missouri | 3,000 | $38,600 | $49,940 | $64,930 |
| Texas | 10,520 | $36,550 | $49,460 | $70,270 |
| Georgia | 3,310 | $36,970 | $48,930 | $67,520 |
| New Mexico | 2,110 | $36,110 | $48,190 | $80,090 |
| West Virginia | 1,100 | $35,360 | $47,560 | $75,240 |
| Kansas | 1,560 | $35,870 | $46,780 | $66,800 |
| Mississippi | 1,150 | $35,230 | $46,480 | $64,130 |
| Louisiana | 2,450 | $31,440 | $46,210 | $63,870 |
| Oklahoma | 2,280 | $35,250 | $45,890 | $63,040 |
| Kentucky | 2,540 | $33,210 | $45,430 | $63,740 |
| Arkansas | 2,010 | $31,480 | $44,320 | $61,780 |
50 states with published estimates.
Source: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics (OEWS), May 2025 — state estimates. Data captured September 30, 2026.
Not yet collected
These dimensions are part of every job page. We publish them only once they are sourced from official documents such as job postings, pay plans, union contracts and state standards.
- 05 ProbationNot yet collectedProbation length and what ends it
- 09 Benefits and pensionNot yet collectedPension plan and formula, retirement age and years, DROP, retiree health, Social Security coverage, 457(b) and PSLF eligibility
- 10 Union contractsNot yet collectedBargaining unit, union and the current contract, with its source and effective dates
- 11 Transfers and lateral entryNot yet collectedLateral entry policy, certification reciprocity, lateral bonuses and moves between agencies
- 15 Employer directoryNot yet collectedEvery public employer that hires this job, with its own pay and rules